Rotary Object Feeder

The present invention is directed to an object feeder, more particularly to a rotary object feeder that feed an object by rotating the object about at least one axis of rotation and preferably, about three parallel, axes of rotation.

Numerous rotary object feeders are known. For example, U.S. Pat. No. 4,518,301 issued May 21, 1985 to R.A. Jones & Co. Inc., discloses an orbital feeder suited for picking up folded cartons from a storage magazine and transporting them to a conveyor, where they are released.

The difficulties with rotary feeders are numerous. The objects to be picked up, such as folded cartons in a magazine, are stationary. It is therefore not possible to simply wipe past the cartons with a pick-up member, typically a suction cup, rotating past the object, with any degree of reliability. Accordingly, a solution to overcome this problem is to alter the path of the pick-up members so that they make contact with the object as they are travelling in a direction generally perpendicular to the plane of the cartons. Rotary carton feeders implementing this solution are known, and incorporate suction cups used as pick-up members mounted on planetary elements. The suction cups move along a hypocycloidal path, and will pick-up objects at points along their path where the suction-cups are travelling in a direction which is perpendicular to the objects. However, because the additional rotation of a planetary element, the perpendicular movement may be somewhat abrupt. Additionally, the object to be picked up is rotated about an additional axis, which may significantly increase the net velocity of the object at certain points along its path. Accordingly, object feeders using this solution do not lend themselves to operation at high speeds. Furthermore to achieve the desired movement, the object is rotated inwardly toward a central axis. This restricts the size and number of objects that can be handled simultaneously by the object feeder.

Moreover, conventional rotary feeders generally use pick-up members that are mechanically linked to the rotation of the feeder. Camming mechanisms, in combination with mechanical air valves, for example, may be used to provide air to suction cups of a feeder, as the feeder rotates. These mechanical arrangements are quite inflexible. They do not allow for the dynamic adjustment of pick-up and drop-off locations around the periphery of the feeder. Moreover, they do not allow adjustment of the release of picked-up objects in response to operating conditions, such as the speed of rotation of the carrier.

It is an object of the present invention to provide a rotary object feeder capable of operating at increased speeds and potentially having increased flexibility in picking-up and releasing objects fed by such a feeder.

In accordance with an aspect of the present invention, there is provided a rotary object feeder comprising: a support; a carrier member rotatably mounted to said support for rotation about a sun axis of rotation; an object pick-up member mounted to said carrier member for rotation therewith; said object pick-up member comprising a suction cup, having an outer surface for picking-up and releasing objects proximate a periphery of said feeder; a vacuum generator having an inlet and an outlet for generating a source of vacuum at said outlet from a source pressurized air at said inlet; said vacuum generator inlet in flow communication with a source of pressurized air; said vacuum generator outlet in flow communication with said suction cup.

In accordance with another aspect of the present invention, there is provided a rotary object feeder comprising: a support; a carrier member rotatably mounted to said support for rotation about a sun axis of rotation; an object pick-up member comprising a suction cup, having an outer surface for picking-up and releasing objects proximate a periphery of said feeder, mounted to said carrier member, for rotation therewith; an electrically controlled air control valve in flow communication with a source of pressurized air and said suction cup to provide suction at said outer surface; a controller, in communication with said control valve, to open and close said control valve to provide suction at said outer surface; a position sensor on said feeder, in communication with said controller to provide a signal indicative of an angular position of said carrier member about said sun axis wherein said controller is adapted to provide suction at said surface in response to sensed, pre-programmed angular positions of said carrier member.

In accordance with yet another aspect of the present invention, there is provided a method of feeding an object from a pick-up location to a drop-off location, on the periphery of a rotary object feeder. The rotary object feeder comprises: a support; a carrier member rotatably mounted to said support for rotation about a sun axis of rotation; an object pick-up member mounted to said support, for rotation therewith; said object pick-up member comprising a suction cup, having an outer surface that passes proximate said pick-up and drop-off location as said carrier member is rotated about said sun axis, said suction cup for picking-up and releasing objects proximate said pick-up and drop-off locations. The method comprises the steps of: a. continuously rotating said carrier member and said pick-up member about said sun axis; b. continuously sensing an angular position of said carrier and said pick-up member relative to said support; c. continuously determining the angular rate of rotation of said carrier; d. applying a vacuum at said suction cup before said suction cup reaches proximate said pick-up location to pick up an object at said pick-up location; e. determining a vacuum turn-off point, in advance of said drop off location, based on said angular rate-of rotation, said turn-off point calculated so that said picked-up object, retained by said vacuum at said suction cup is released at said drop-off location in response to turning-off said vacuum at said vacuum turn-off point; f. turning off said vacuum at said suction cup as said suction cup reaches said turn-off point.

Preferably, a rotary object feeder in accordance with this invention, feeds objects from a first location to a second location by rotating the object about three axes. Such an object feeder feeds the object from a pick-up location to an off-loading location, by moving an object pick-up member along a trajectory formed by rotating the object pick-up member about a first axis of rotation; rotating this first axis of rotation about a second axis of rotation substantially parallel to the first axis of rotation and spaced therefrom; rotating the second axis of rotation about a third axis of rotation substantially parallel to the second axis of rotation and spaced therefrom. The first, second and third axes of rotation may be analogized to moon, planet and sun axes in a solar system.

The resulting trajectory of the object about a third axis is hypocycloidal. The object passes at least one point at which the object is at a farthest distance from this third axis. This farthest location is reached when the object, the first axis, the second axis and the third axis of rotation are collinear. This location can be considered a vertex of the object's trajectory. At this point, the object will change its radial direction away from the first axis toward the second axis. The number of vertices along the object's trajectory as the object rotates about the third axis will vary deeding on the relative rates of rotation of the first axis about the second axis and the second axis about the third axis.

For example, if the first axis is rotated more quickly about the second axis than the second axis is rotated about the third axis, the object's trajectory will have at least one vertex for each rotation of the object about the third axis. Similarly, if the first axis rotates about the second axis at a rate of rotation slower than that of the second axis about the third axis, the object will only reach a vertex of its trajectory after the second axis has rotated about the third axis at least once.

Additionally, the choice of distances from the first axis to the second axis; from the second axis to the third axis; and from the third axis to the object combined with the relative rates of rotation of the object about its three axes may be chosen to minimize the tangential velocity of the object in its orbit about the third axis at these vertices.

Ideally, the rate of rotation of the second axis about the third axis (angular velocity .omega..sub.1), and the rate of rotation of the first axis about the second axis (angular velocity .omega..sub.2)will be chosen as integer multiples of each other, with .omega..sub.2 >.omega..sub.1. Thereby the trajectory of the object will have .omega..sub.2 /.omega..sub.1 vertices for each rotation of the second axis about the third axis. The location of these vertices relative to some fixed point, (for example, the location of the third axis) may be arbitrarily selected and will remain the same for each rotation of the second axis about the third axis.

The use of three axes of rotation may further permit the object as it rotates about the third axis to face generally outward from the third axis at all times. Thus when the invention is embodied in a rotary object feeder, relatively large objects may be picked-up and transported on a rotary carrier. The objects remain generally on the periphery of the carrier without being rotated toward its centre. Additionally, the path taken by the object may be made smoother and its velocity may be minimized the object is rotated about the third axis at an angular velocity equal in magnitude but opposite in direction to the magnitude and direction of the angular velocity of the first axis about the second axis. As a result, rotary object feeders in accordance with this invention lend themselves to use at very high speeds.

A rotary object feeder in accordance with this invention need not be limited to a single pick-up member rotatably mounted about three axes. An object feeder in accordance with this invention may have any number of pick-up members, each having arbitrary rates of rotation about a first, second and third axis. In this way, the invention may extend to a rotary canton feeder, in which the pick-up members may be analogized to moons in a solar system having numerous planets.

As the preferred embodiments detailed herein reveal, this invention is particularly well suited for use with a rotary carton feeder which will have enhanced advantages when numerous planetary members are mounted about a third axis such that the pick-up members reach vertices along their trajectories at equidistant points from the third axis. Moreover, if numerous pick-up members rotate about a third axis, it will be advantageous if a number of these pick-up members travel along identical trajectories so that they reach the vertices of their paths at the same locations. The vertices may then be used as pick-up, operating and drop-off locations for an object.

The preferred embodiments described herein are directed to

Embodiment 1--a rotary carton feeder having three pick-up members. travelling along an identical trajectory having three vertices along its path;

Embodiment 2--a rotary carton feeder having six pick-up members, each pick-up member travelling along a trajectory having three vertices, three of the pick-up members travelling along one trajectory, three other pick-up members travelling along a different trajectory;

Embodiment 3--a rotary carton feeder having six pick-up members, each pick-up member travelling along an identical trajectory having three vertices; and

Embodiment 4--a rotary carton feeder having six pick-up members, each pick-up member travelling along an identical trajectory having six vertices.

In the drawings which illustrate preferred embodiments of the present invention,

FIG. 1 is a perspective view of an object feeder having 3 pick-up heads, in accordance with one aspect of the present invention;

FIG. 2 is a schematic of the embodiment of FIG. 1, in operation;

FIG. 2a is another schematic of the embodiment of FIG. 1.

FIG. 3 is a scrap view of a portion of the object feeder of FIG. 1, marked as 3 in FIG. 4;

FIG. 4 is a cross sectional view from the side, of part ore object feeder of FIG. 1;

FIG. 5 is an end view of the embodiment of FIG. 1, taken along 5--5 of FIG. 4;

FIG. 6 is an end view of the embodiment of FIG. 1, taken along 6--6 of FIG. 4;

FIG. 7 is a perspective view of an object feeder having six pick-up heads in accordance with another embodiment of the present invention;

FIG. 8 is a plan view of the rear of the object feeder of FIG. 7;

FIG. 9 is a schematic view of another object feeder having six pick-up heads in accordance with another embodiment of the present invention in operation;

FIG. 10 is a schematic view of another object feeder having six pick-up heads in accordance with another embodiment of the present invention;

FIG. 11 is a schematic of the embodiment of FIG. 7, in operation;

FIG. 11a is a schematic view of the object feeder of FIGS. 7 and 11;

FIG. 12 is a block diagram of a programmable limit switch used in the feeder of FIGS. 1-6;

FIG. 13 is a block diagram of a programmable logic controller used in the feeder of FIGS. 1-6;

FIG. 14 illustrates a component used in the feeder of FIGS. 1-6;

FIG. 15 illustrates the relationship between valve turn-off points and drop-off points, for various carton feeder speeds, as used by a speed compensation method used by the controller of FIG. 12.

Embodiment 1

With reference to FIGS. 1-6, there is provided a rotary object feeder generally designated 18 having three identical planetary assemblies 22a, 22b and 22c.

As shown in FIGS. 1, 3, 4, 5 and 6, there is provided a rotary object feeder 18 having a carrier member 20. Carrier member 20 is comprised of two circular disks 50 and 52. Disks 50 and 52 are made of a durable, rigid material such as steel or aluminum. A main shaft 36 is fixedly mounted to disk 52. Main shaft 36 is coaxial with a sun axis 30. A sun gear 38 is fixedly mounted on a support frame 16, adjacent to the rear side of disk 52 farthest from disk 50. Sun gear 38 is mounted on main shaft 36 and has a centre axis coincident with sun axis 30. Shaft 36 is rotatable relative to fixed sun gear 38.

Three identical planetary members 22a, 22b and 22c are mounted on carrier member 20. The three planetary members 22a, 22b and 22c are mounted about planetary axes 32a, 32b and 32c at equal distances from sun axis 30, and at equal distances from each other. Only one planetary member 22a will be described herein in detail but it will be understood that planetary members 22b and 22c are identical in structure.

Planetary member 22a is rotatably mounted on carrier member 20 about a planetary axis 32a. Planetary axis 32a is oriented parallel to sun axis 30. Planetary member 22a is comprised of circular disk 54a and a lever 56a. Circular disk 54a and lever 56a are made of a material similar to that of circular disks 50 and 52. Circular disk 50 has a circular cut-out for seating planetary member 22a and particularly disk 54a. Disk 54a may be mounted with its outer surface flush with the outer surface of disk 50. Bearings 80a are interposed between disk 50 and disk 54a.

An idler gear 44a is rotatably mounted on disk 52 about shaft 33a so that it is freely rotatable about shaft 33a relative to disk 52 on the side of disk 52 farthest from disk 50. Idler gear 44a engages sun gear 38. Idler gear 44a also engages a planetary gear 46a. Planetary gear 46a is fixedly mounted on planetary shaft 48a, near an end of a planetary shaft 48a. Planetary shaft 48a extends through a cut away in circular disk 52, and through a cut away in circular disk 56a. A fixing shaft 58a is attached at one end to disk 54a and at another to lever 56a. Fixing shaft 58a acts as a counterweight mounted between disk 54a and lever 56a, diametrically opposite moon shaft 60a and is adapted in combination with the shaping of lever 56a to balance the weight of planetary system 22a about planetary shaft 48a, thereby providing a smooth balanced rotation about axis 32a.

A second end of planetary shaft 48a is fixedly attached to disk 54a at the centre of disk 54a. A housing 62a is fixedly mounted to the inner side of circular disk 52 and surrounds planetary shaft 48a. Ball bearings 84a are mounted in housing 62a and are interposed between planetary shaft 48a relative to housing 62a, thus permitting rotation of shaft 48a without housing 62a. Attached to the end of housing 62a proximate an inner side of lever 56a closest to lever 56a, is a planetary sun gear 70a. An idler gear 72a is rotatably mounted on an inner side of lever 56a closest to circular disk 54a on shaft 53a, and engages planetary sun gear 70a. A moon gear 74a is fixedly mounted to moon shaft 60a. Moon gear 74a is also engaged by idler gear 72a.

Moon member 24a is fixedly mounted on moon shaft 60a on planetary member 22a and is rotatable, about moon axis 34a with moon shaft 60a. Moon member 24a has an extension member 40a and a shaft 42a. Shaft 42a extends from extension member 40a in a direction parallel to moon axis 34a. Extension member 40a is mounted to moon shaft 60a near one of its ends 34. Extension member 40a is generally rectangular in shape, made of a rigid material, and mounted near one of its ends with its long axis perpendicular to moon axis 34a. Object pick-up member 26a is fixedly mounted on shaft 42a and has a pair of vacuum suction cups 28a.

Extension member 40a and shaft 42a are designed so that suction cups 28a have their pick-up surface along moon axis 34a.

Mounted on shaft 42a atop suction cups 28a is a vacuum generator 102a. Vacuum generator 102a is a venturi vacuum generator that uses compressed air at an inlet and converts this compressed air into a stream of attracted air (ie. a vacuum) at a vacuum outlet. The suction cups 28a are connected to the vacuum outlet by a very short hose 25a (less than 10 cm in length, and optimally less than 2.5 cm in length). As will be detailed below, this close proximity of vacuum generator 102a to suction cups 28a, allows for very fast, cut-off of the vacuum at suction cups 28a. A vacuum generator 102a suitable for use with the feeder is produced by Pisco.TM. Pneumatic Equipment, sold under model No. VCH10-016C or VCH10-018C. The vacuum generator is designed to operate at a pressure of approximately 72 psi. Advantageously, a vacuum generator of this type has near flat input pressure versus output vacuum characteristics near its chosen operating point. Thus, slight deviations in input pressure about the designed operating point (72 p.s.i.), have minimal effects on suction generated by the vacuum generator.

The inlet of vacuum generator 102a is connected to hose 110a. The other end of hose 110a is connected to nib 104a. Hose 110a thus provides a means of air communication between vacuum generator 102a and nib 104a. Nib 104a extends in a direction along axis 32a from moon shaft 60a which is hollow. The hollow interior of moon shaft 60a forms an air passage 114a from an end connector 106a to nib 104a. End connector 106a is mounted on swivel joint 122a which permits end connector 106a to rotate about axis 34a. End connector 106a is connected to an end of hose 112a. The other end of hose 112a is connected to nib 108a. Nib 108a extends in a direction perpendicular to axis 32a from planetary shaft 48a which is also hollow. Planetary shaft 48a defines air passage 116a which extends from connector 117a to nib 108a. Connector 117a is mounted on swivel joint 121a permitting connector 117a to rotate about axis 32a. Hose 118a extends from (connector 117a to an electronic control valve (not shown). A hose (also not shown) extends from the electronic control valve to manifold 124. The hose is connected to a nib (not shown) on the manifold. Corresponding electronic control valve 130b and nib 120b, associated with planetary member 22b, are however shown in FIG. 4.

Control valve 130b is connected by hose 131b to nib 120b and controls the air flow to vacuum generator 102b (FIG. 1). Control valve 130b is a normally closed solenoid valve, having an inlet and outlet. It limits pressurized air from flowing through from the inlet to the outlet, when de-energized and closed; it permits air to flow from inlet to outlet when energized and open. The valve may be energized by application of a +24 volt direct current signal to the solenoid. A suitable electronic control valve for use in this embodiment is sold by MAC.TM. Valves as part No. 111B/113B-111CA. Nib 120b extends from manifold 124 and air passage 119b passes through hollow shaft 36.

A connector 126 extending from an end of shaft 36 is connected to a source of pressurized air (not shown).

Control valve 130b is electrically connected to output control wires 140b and 142b which extend from slip ring 37. One of the control wires provides an electric off/on signal to energize and de-energize, thereby opening and closing control valve 130b, while the other is a ground connection. Of course, it would be possible to provide the ground connection of the control valve by means of the metal forming the carrier and planetary member. The output control wires 140b and 142b are fixed relative to disc 52 and make contact with input control wires 39 through slip ring 37. Input control wires 39 are stationary relative to support 16 on the opposite side of slip ring 37. A suitable slip ring for use as part of the feeder is sold by Litton.TM., as part No. AC4598. This slip ring has eight input and eight output wires and may be used to carry both control and ground signals to the three rotating solenoid control valves (130b, and those associated with planetary members 22a and 22c). The slip ring 37 is mounted about sun axis 30, which is the central axis about which control wires 140b and 142b (as well as the remaining control wires extending to the remaining control valves) rotate. Two of the wires of the eight wire slip ring are used for each solenoid control valve, while the two remaining wires are unused.

A computer control system or controller comprising programmable logic controller ("PLC") 178 and programmable limit switch ("PLS") 150, as illustrated in block diagram in FIGS. 12 and 13, forms part of feeder 18.

PLC 178 comprises processor 179, memory 180 (programmable and read-only); keyboard/keypad 182; output port 183; input port 189; and input/output port 181. Memory 180 stores a program governing the operation of PLC 178. This program may be stored in read-only-memory or in dynamic memory and may be input to PLC 178 by means of keyboard 182 or input/output port 181. A further display (not shown) may be interconnected with processor 179. Input/output port 181 is further connected to input/output port 170 of PLS 150. Output port 183 is interconnected to relay bank 184. Relay bank 184 comprises three solid state permissive relays 184a, 184b and 184c relays each controlled by PLC 178. Relay bank 184 has three outputs connected to input control wires 39. Each of the control wires 39 may be independently energized to energize a corresponding control valve at output control wires 140, directly from a PLC output from PLC output port 183. Additionally, connected to control wires 39 are three permissive solid state relays 184a, 184b, 184c that take as their inputs, outputs 164a, 164b, and 164c of PLS 150. Once energized, by the PLC 178 permissive relays provide a pass-through connection to outputs 164a, 164b and 164c. Thus, if the direct PLC outputs at port 183 are not energized, the state of control wires 39 is controlled directly by outputs 164a, 164b and 164c of PLS as long as permissive solid state relays 184a, 184b, 184c, are energized by PLC 178, Alternatively, the direct PLC outputs at port 183 may directly energize control relay 130b (and those associated with planetary members 22a and 22c).

Additional control points on feeder 18, or on a packaging system incorporating feeder 18 may be activated by additional control outputs 190 of control port 183. For example, PLC 178 may control the speed of the motor driving carrier 18 through shaft 36.

Further, input port 189 is in communication with a plurality of control sensors 185, 186, 187, and 188. These sensors may send operating conditions of feeder 18 or other conditions, such as the activation/deactivation of interlocks connected to feeder 18 and a packaging apparatus incorporating feeder 18; the presence or absence of objects to be fed; or the like.

Specifically sensors 185 and 186 are two proximity sensors mounted on feeder 18. Sensors 185 and 186 sense metal flags 195 and 196 mounted about shaft 36. Flags 195 and 196 are illustrated in FIG. 14. Flags 195 and 196 are two flat pieces of metal, forming a 240.degree. segment of a circle. They are rotatably mounted about shaft 36, at orientations offset by 120.degree.. By sensing the presence or absence of each of the flags near the proximity sensors 186, 186, processor 179 of PLC 178, can determine which of the planetary member 22a, 22b and 22c, are within each of three 120.degree. segments about sun axis 30. Thus, PLC 178 through sensors 185 and 186 may determine the presence or absence of any planetary member 22a, 22b and 22c in any segment.

PLS 150, comprises a processor 152, memory 154 (program and read-only), an input keyboard/keypad 156, a plurality of sensor inputs 158, 160, and 162 through input port 165, and control outputs 164a, 164b and 164c through output port 163. An input/output port 170 is further in communication with processor 152. This input/output port 170 allows for the exchange of data and controller programming instructions with PLC 178 or another external computer or controller (not shown). Input/output port 170 is interconnected to input/output port 181. Alternatively, program instructions and parameters may be provided to PLS 150 by means of keyboard/keypad 156. Display information may be presented by PLS 150 at display 155, which is typically an array of alphanumeric LEDs. PLS 150 provides control signals by means of control outputs 164b, through wires 39 and 140b and 142b, and relay panel 184 in order to energize and de-energize, and thereby open and close valve 130b. This in turn, may activate and de-activate the flow of compressed air to vacuum generator 102b on planetary member 22b. Compressed air provided to vacuum generators on planetary members 22a and 22c are similarly provided by providing control signals at outputs 164a and 164c. PLS 150 is a programmable limit switch, such as one produced by the PLUS Controls Division of Electrocam Corporation and sold as model no. 5144.

Additionally, with reference to FIG. 12 an electromechanical resolver 99 is connected to one of the sensor inputs 160 and is in communication with PLS 150. Preferably, the resolver is mounted about the drive mechanism that provides rotational power to shaft 36. Alternatively a resolver could be mounted to the periphery of the carrier 20. The resolver 99 is mounted to the drive mechanism of the feeder 18 so that it is mechanically linked with the rotation of carrier 20. The resolver 99 is geared so that one rotation of carrier 20 causes three complete rotations of resolver 99. Additionally, resolver 99, generates a digital eight or ten bit signal, corresponding to an angular rotation of the drive of feeder 18 and therefor, an angular position indicative of the position of carrier 20. However, as resolver 99 is geared to rotate three times for each rotation of carrier 20, the signal provided by resolver 99 is actually indicative of the orientation of any of the planetary members 22a, 22b, and 22c about their planetary axes. This digital eight or ten bit signal is provided to PLS 150 at input 160. Viewed another way, resolver 99 provides PLS 150 a 10 signal indicative of the position of carrier 20 within a 120.degree. segment of the rotation of carrier 20 about sun axis 30. Thus PLS 150 is provided with a sensed signal representative of the angular position of carrier 20, relative to support 16 about sun axis 30 at all times. The position sensed by PLS 150 is provided to PLC 178 by port 170. PLC 178 can calculate the precise position of each pick-up member 26a, 26b, and 26, by determining the 120.degree. segment in which each planetary member is located using proximity sensors 185 and 186 and discs 195 and 196, and the angular position within each segment using resolver 99 output sensed by PLS 150. An exemplary angular position sensor, used by PLC 178 to determine the angular position of carrier 20 about sun axis 30 is thus comprised of resolver 99, in combination with flags 185, 186 and proximity sensors 195 and 196.

PLS 150 further generates an internal time signal. By using the sensed signal representing angular position, and the internal Little signal, PLS 150, by means of its processor 152, may calculate the rotational speed (angular velocity) of carrier 20 at all times.

In operation, a source of rotational power, provided by motor (not shown), drives shaft 36 at an angular velocity of .omega..sub.1. Compressed air is fed to connector 126. Shaft 36 causes disk 52 and disk 50 along with planetary members 46a, 46b and 46c and their corresponding planetary axis, to rotate about the sun axis 30 at angular velocity .omega..sub.1 and relative to sun gear 42. Consequently, idler gear 44a is driven about sun gear 38 and engages sun gear 38 to cause idler gear 44a to rotate about its shaft 33 in a direction the same as the direction of rotation of disk 52, as illustrated in FIG. 5. Planetary spur gear 46a is engaged by idler gear 44a and is rotated about its planetary axis 32a in the opposite direction as idler gear 44a and disc 52 at an angular velocity .omega..sub.2. Planetary spur gear 46a, fixedly attached to planetary shaft 48a, causes planetary shaft 48a to rotate with spur gear 46a. Planetary shaft 48a, attached to disk 54a causes disk 54a to rotate along with planetary shaft 48a at an angular velocity .omega..sub.2. As lever 56a is attached to disk 54a by fixing shaft 58a, lever 56a rotates with disk 54a about axis 32a. As disk 54a rotates about planetary axis 32a, so does moon shaft 60a and its moon axis 34a.

Planetary sun gear 70a is attached to housing 62 and is stationary with respect to disk 52. Idler gear 72a, secured to lever 56a by shaft 53, is driven about and engages planetary sun gear 70a. Idler gear 72a thereby rotates about shaft 53a in the same direction of rotation as disk 56a. Moon spur gear 74a is engaged by idler gear 72a and moon spur gear 74a thereby rotates in the opposite direction as idler gear 72a and disc 54a, with an angular velocity .omega..sub.3 equal in magnitude to .omega..sub.2. As spur gear 74a is fixedly attached to moon shaft 60a, moon shaft 60a rotates with moon spur gear 74a. Moon member 24a rotates along with moon shaft 60a.

The gear ratios of sun gear 42, idler gear 44a and planetary spur gear 46a in this embodiment are chosen so that planetary system 21a and hence moon member 24a rotates 3 times about planetary axis 32a for each rotation of carrier 20 about its axis of rotation 30 (ie. .omega..sub.3 /.omega..sub.1 =3). The gear ratios of planetary sun gear 70a, planetary idler gear 72a and moon gear 74a are chosen so that moon member 24a rotates once about moon axis 34a for every rotation of sun member 22a about planetary axis 32a, but in the opposite direction (ie. .omega..sub.2 /.omega..sub.1 =-1).

As pick-up member 26a rotates in a direction opposite the direction of rotation of planetary member 22a at the same angular velocity as planetary member 22a, pick-up member 26a and suction cups 28a will always remain generally outwardly facing. Particularly, extension member 40a is mounted so that pick-up member 26a is always outwardly facing with respect to axis 30.

As carrier member 20 rotates, pick-up member 26a traverses a generally triangular trajectory 88 as shown in FIG. 2. At the vertices of this triangular trajectory 88, the velocity of suction cups 28a in a direction tangent to the rotation of the carrier is zero. This zero tangential velocity results from the contribution of the rotation of pick-up member 26a about axes 34a, 32a and 30. Zero tangential velocity at the vertices is achieved through a balancing choice of the ratios of rotation of planetary member 22a to carrier member 20; the positioning of axes of rotation 34a, 32a and 30 and the choice of the length of extension member 40a, as will be described later in further detail.

In FIG. 2a, all three pick-up members 26a, 26b and 26c are illustrated again, is showing how the apparatus is arranged so that each pick up member will reach a vertex at the same instant in time.

Referring again to FIG. 2, as pick-up member 26a passes along its triangular trajectory, suction cups 28a pass through pick-up location 90. Located at pick-up location 90 is a carton magazine or feeder (lot shown) for holding folded cartons. Suction cups 28a make contact with a top-most folded carton at pick-up location 90 while travelling in a direction perpendicular to the planar surface of the folded cartons. Before pick-up member 26a passes through pick-up location 90, an electric control valve (not shown, but corresponding to control valve 130b associated with planetary member 22b) receives a signal from controller (PLS 150 and PLC 178) (FIGS. 12, 13), to provide pressurized air to the inlet of vacuum generator 102a.

PLC 178 and PLS 150 (FIG. 12), are programmed to activate (ie. energize) the control valve associated with vacuum generator 102a in response to sensing the angular location of planetary member 22a on carrier 20, relative to sun axis 30. With reference to FIGS. 2 and 2a, typically, the control valve is activated about 60.degree. (measured about sun axis 30) before pick-up member 26a reaches pick-up location 90, approximately rotationally half-way between drop-off location 94 and pick-up location 90. The control valve is initially energized by a PLC output of PLC output port 183.

In response to receiving a signal at the control valve, pressurized air is fed to vacuum generator 102a via air passages or cavities 126, 116a, 114a and hoses 118a and 112a. Vacuum generator 102a converts this pressurized air into a constant source of suction. As noted, because of the relatively flat relationship between vacuum output and air pressure input, the precise pressure at the vacuum generator inlet may vary somewhat from its design point without materially affecting the operation of the vacuum cups 28a. This suction is fed to suction cups 28a, by hose 25a, thereby causing a folded carton at location 90 to adhere to suction cups 28a. The electrical control valve retains pressurized air at vacuum generator 102a and thereby suction at suction cups 28a until suction cups 28a releases the can near drop-off location 94.

Suction cups 28a transport a folded carton from pick-up location 90 along trajectory 88 to operating location 92. As the folded carton travels from pick-up location 90, suction cups 28a remain outwardly facing because of the rotation of suction cups 28a in an opposite direction and at an angular velocity equal to that of planetary member 22a.

As the shaft 36 and manifold 124 rotate, the distance between axis 32a and axis 30 does not change. Thus the distance between a nib on the manifold and its corresponding, connecting nibs on a planetary member does not change.

As connector 117a attached by swivel joint 121a to swivel about axis 32a, hose 118a does not become twisted as manifold 124 rotates.

The same principle applies to hose 112a between nib 108a and connector 106a, the latter of which is adapted to swivel about axis 34a by means of swivel joint 122a, and in respect of hose 110a which links vacuum generator 102a to nib 104a. Nib 104a need not rotate about axis 34a because there is no movement of shaft 42a relative to shaft 60a.

Located at operating location 92 is a carton expander unit (not shown). At operating location 92, the folded carton has zero tangential velocity. The carton expander is located tangent to carrier 20 at operating location 92. The expander engages the folded carton and pulls the carton apart in a direction radial to carrier 20. Suction cups 28a further transports the unfolded carton along trajectory 88 to off-loading location 94. As suction cups 28a approach off-loading location 94 PLC 178 switches the functioning of relay bank 184, so that energy provided to the control valve is no longer provided by a direct PLC output of PLC output port 183 of bank 184. Instead, energy is provided to the control valve by PLS 150 through output 164a, conducted through a permissive relay 184a. PLS 150 continues to energize the control valve associated with planetary member 22a until the suction cups reach a precise "turn-off" point. At this turn-off point, the control valve is de-energized and the negative pressure at suction cups 28a is released. However, before suction cups 28a release an attached carton, the vacuum at suction cups 28a must be released. Thus, pressurized air at the vacuum generator associated with suction cups 28a must be cut off, and the vacuum at suction cups 28a must be released. As the distance between the control valve and the vacuum generator associated with cup 28a is finite and because air must bleed into the vacuum passage connected to suction cups 28a to release the vacuum, the time and location at which the control valve associated with planetary member 22a is closed (ie. the turn-off point) and the corresponding time and location (ie. the "drop-off point") where an object attached to suction cups 28a is released are not identical. At slow speeds of rotation, the time difference between turn-off of the control valve and the drop-off of an attached carton is insignificant. As the rate of rotation of the feeder increases, the time difference between the turn-off and drop-off points results in an increased angular difference between the turn-off and drop-off point.

Accordingly, PLS 150 is adapted by means of software stored in memory 154 to dynamically adjust the turnoff point for the control valve, associated with planetary member 22a, relative to the drop-off location 94. This function of PLS 150 is referred to as "speed compensation". The program is adapted so that, as the rotational speed of feeder 18 increases, as sensed by resolver 99, and PLS 150, the position of the control valve turn-off point, for a control valve associated with a pick-up member approaching drop-off location 94 is advanced linearly as shown in FIG. 15. Specifically, the turn-off point is advanced approximately 250.degree. about sun axis 30 for every 1000 rpm of carrier 20. Thus, as illustrated in FIG. 15, for speeds of rotation allowing for the delivery of 400 objects/minute (=133 rpm), the turn-off point for suction cups 28a is advanced by approximately 32.degree. (as measured about axis 30). That is, the vacuum at suction cups 28a is turned off as the planetary axis 32a associated with suction cups 28a is approximately thirty twos degrees away from drop-off location 94. This advancement is directly related to the approximate time required to stop air flow to vacuum generator 102a and bleed the vacuum at suction cups 28a. As vacuum generator 102a is advantageously close to suction cups 28a, and the associated control valve is mounted in proximity to the vacuum generator 102a, a very quick release of the vacuum at the suction cups 28a is possible. If the vacuum generators were eliminated entirely, or moved away from the suction cups, the time required to bleed the vacuum at the suction cups would increase significantly, making high speed delivery of objects, difficult, if not impossible.

Once the vacuum at suction cups 28a is released, the unfolded carton having near zero tangential velocity at off-loading location 94 will be released.

Located at drop-off location 94 is a transport mechanism (not shown) on which the unfolded carton is released. The unfolded carton is then transported by the transport mechanism away from the carton feeder to a location (not shown) where the carton is further processed.

Pick-up location 90, operating location 92 and drop-off location 94 are equally spaced from each other along the periphery of carrier 20. While pick-up member 26a follows trajectory 88, pick-up member 26c follows the same trajectory, but lags by 120.degree. of rotation of carrier 20. Similarly, pick-up member 26c further lags 120.degree. behind pick-up member 26b. Thus, when pick-up member 26a passes through pick-up location 90, pick-up member 26c passes through off-loading location 94, and pick-up member 26b passes through operating location 92. Vacuum generators 102b and 102c are actuated as pick-up members 26b and 26c pass through pick-up location 90. Using speed compensation, as described above, the cartons picked up by pick-up members 26b and 26c are released as pick-up members 26b and 26c pass through off-loading location 94. Again the pick-up and release is controlled by a controller comprised of PLC 178 and PLS 150. Thus, for each rotation of carrier 20 about axis 30, three folded cartons are picked-up at pick-up location 90, expanded at operating location 92 and released at off-loading location 94.

While a controller comprised of PLC 178 and PLS 150 has been described with reference to a rotary feeder having three pick-up heads, each for rotation about three axes, a person skilled in the art will appreciate that such a controller could easily be associated with a rotary feeder having any number of heads, each rotating about one, two, three or more axes of rotation. Such a controller could similarly implement the speed compensation described above. Additionally, in the event that PLC 178 is not used for sensing other operating conditions, a controller could be implemented solely using PLS 150; alternatively the controller could be implemented solely by PLC 178.

Additionally, as the pick-up and drop-off location of each of the pick-up members 26a, 26b and 26c are governed by a controller comprised of PLC 178 and PLS 150, pick-up, operating and drop-off locations may be re-arranged through software control loaded into PLC 178 and/or PLS 150, at any time.

In some applications, it is possible for the vacuum generator to be eliminated and a vacuum applied through the entire air system. As will be understood, however, the shorter the distance between each of the suction cup 28a, 28b, and 28c and the associated control valve, the more accurate control of suction at suction cups 28a, 28b and 28c will be possible.

Embodiment 2

With reference to FIG. 9, there is provided a rotary object feeder generally designated 218 having two sets of three identical planetary members; a first set 200a, 200b, 200c; and a second set 202a, 202b, and 202c.

The size of planetary members 200, 202 and the carrier member 220 are chosen, so that two sets of three planetary members may be mounted on a single carrier member.

In this embodiment, the six planetary members are arranged to function as two sets of three planetary members. The first set comprising planetary member 200a, 200b, and 200c having moon members 210a, 210b and 210c mounted thereon. Each moon member further comprises a pick-up member 206a, 206b and 206c. Each pick-up member 206a, 206b and 206c travels along hypocycloidal trajectory 288 generally in the triangular pattern illustrated.

Each of the sets of moon members 204 and 210 rotate three times about a planetary axes for each rotation of carrier 220 about a sun axis, in an opposite direction as carrier 220. The pick-up members 204, travel along the trajectory 288 but lag pick-up members 206, by 60.degree. of rotation of carrier member 220 about sun axis 230.

The vertices of the trajectory 288 are located at positions, 290, 292 and 294. Each of the pick-up members 204 and 206 pass through each vertex once for every rotation of carrier 220. Located at these vertices are a folded carton feeder, an operating unit and a transport unit respectively, as with the embodiment 1 shown in FIGS. 1-6. As in Embodiment 1 of FIGS. 1-6, a vacuum generator associated with each of members 204, and 206 is actuated as each of the pick-up members passes through the pick-up location 290. Suction cups forming pick-up members 204 and 206 pick-up a folded carton at pick-up location 290, transport it to operating location 292 where the folded carton is expanded, transport it to a further off-loading location 294 where it is released.

Once again, the presence or absence of suction at the suction cups of pick-up members 204a, 204b, 204c and 206a, 206b, and 206c is controlled by a controller system similar to controller comprised of PLS 150 and PLC 178 of FIGS. 12 and 13, and associated electric control valves (not shown) are mounted to the rotating carrier portion of the feeder, and provided with control signals by means of control wires connected by way of a slip ring. The controller, again, allows for the independent control of suction at the pick-up heads, thereby allowing for independent control of each of the pick-up heads 204a, 204b, 204c, 206a, 206b, 206c, similar to the control of suction at suction cups 28a, 28b and 28c of embodiment 1. The controller of this embodiment, again implements the speed compensation, as described above, to ensure proper release of articles picked up by pick-up member 204 and 206 at location 294.

With the proper choice of angular velocities, position of axes and the proper mounting of the pick-up members, each suction cup will pass through pick-up 290, operating 292 and off-loading location 294 with zero tangential velocity.

Embodiment 3

It is possible that the general concept of the invention may be adapted to allow several planetary members to each follow a different trajectory. In FIG. 10, pick-up members of each set of three planetary members follow a different trajectory.

Accordingly, in operation one set of moon members 208a, 208b, 208c follows a generally triangular trajectory marked as 250. A second set of moon members 210a, 210b and 210c follows a similar generally triangular trajectory generally marked as 252. The vertices of each trajectory of each set of suction cups associated with pick-up members 208a, 208b, 208c and 210a, 210b and 210c are at different locations relative to the frame support (not shown). A rotary feeder according to such an embodiment may be adapted for two pick-up locations 280, 290, two operating locations 282, 292 and two off-loading locations 284, 294. Each set of pick-up members 208 and 210 will pass along a generally triangular trajectory 250 or 252 having one of the pick-up locations 280 or 290; one of the operating locations 282 or 292 and one of the off-loading locations 284 or 294 at its vertices. The rotary feeder may be used to feed six folded cartons from two different pick-up locations to two different off-loading locations for each rotation of carrier member 220.

Once again, the presence or absence of suction at the suction cups of pick-up members 204a, 204b, 204c and 206a, 206b, and 206c is controlled by a controller similar to Embodiment 1. This controller, again implements the speed compensation to ensure proper release of picked-up articles at location 294 for pick-up members 206 and location 280 for pick-up members 204.

Additionally, as the controller dynamically controls the provision of suction at the suction cups of pick-up members 204 and 206, it is possible to use program control to de-activate either set of pick-up members 204 or 206, individually. This, for example, might allow for the replenishment of cartons to be fed at locations 290 or 282 without interrupting the transfer of cartons by the remaining set of pick-up members.

Embodiment 4

The general inventive concept of the present invention, is not limited to rotary feeders having pick-up members rotating at three times the rate of a carrier member. FIGS. 7, 8, 11 and 11a, for example, illustrate a rotary object feeder having six pick-up members. In this embodiment, each planetary member 322a-322f is geared so that it rotates six times about planetary axes 332a-332f for each rotation of carrier member 320 about sun axis 330. The trajectory 388 of each planetary member is accordingly pseudo-hexagonal with six vertices, as shown in FIGS. 11 and 11a. As the relative radii and rates of rotation of carrier member 320 to planetary members 322a-322f, differs from the Embodiments 1, 2 and 3, the length of mounting shafts 326a-326f are chosen to achieve a minimum tangential velocity of pick-up members 328a-328f at these vertices. Accordingly, the carton feeder may be adapted to have two sets of pick-up, operating, and off-loading locations, or it may he adapted to have a single pick-up and off-loading location with four operating locations, depending on the requirements of the particular application.

Suction at the suction cups of pick-up members 328a-328f is controlled by a computer controller (similar to the controller of embodiment 1) and associated electric control valves and vacuum generators proximate the pick-up members, as described above. The controller, independently controls suction at each of the suction cups associated with pick-up members 328a-328f. Thus, the pick-up, and operating locations may be dynamically adjusted by program control implemented by an associated controller. For example, the controller could direct pick-up members 328a, 328b and 328c to pick-up cartons to be delivered to a single off-loading location, from three distinct pick-up locations. Similarly, the pick-up or drop-off location for any pick-up member could be changed dynamically, as the feeder is in operation. Thus, the controller could direct a pick-up head to feed from a first location until cartons at that location are exhausted, then the controller could direct the feeder to feed cartons from a second location until cartons at the first location are replenished, at which time cartons could be fed again from the first location. Of course, any desired combination of pick-up and drop-off locations is possible: the key is that suction at each pick-up member is independently controlled by a controller (similar to the controller of embodiment 1), so that program control may direct the pick-up and drop-off of objects by each pick up member 328a-328f.

In the embodiment illustrated in FIG. 7, each object pick-up member will pick-up a folded carton from a magazine at a loading station 390. The folded carton is then rotated about the path shown in FIG. 11 to a carton erection station 392. At station 392 a conventional carton erection apparatus is located, such as a vacuum source mounted on a reciprocating arm. The motion of the pick-up member may be such as to obviate the necessity for a separate reciprocating arm. Once the carton has been erected the carton is rotated to an unloading station where the vacuum at the suction cups in turned off, and the carton is allowed to he deposited onto a conveyor which removes the carton from the station. If the carton is stationary at the station 394, this carton feeder will be particularly suitable for use in combination with a hesitating carton loading system such as that disclosed in U.S. Pat. No. 5,371,995 issued Dec. 13, 1994 to Guttinger et al.

In FIG. 8 an alternate drive mechanism to the gearing mechanism described above, is shown for the planetary members in a 6 pick-up member rotary system. A sunwheel 438 is fixedly mounted to a support frame (not shown). Sunwheel 438 has mounted along its periphery a number of gear teeth. Disk 450 is mounted to shaft 436, and rotates relative to sunwheel 438. Gears 498 are rotatably mounted on one side of disk 450, and are connected to planetary members 322. Planetary members 322 are mounted on an opposite side of disk 450. A chain 499 mounted about sunwheel 438, gears 498 and idler gears 497. In operation, shaft 436 is driven by a source of rotational power. Disk 450 rotates relative to sunwheel 438. Chain 499 travels along the periphery of sunwheel 438 and engages the gear teeth of sunwheel 438, and thereby moves relative to sunwheel 438. This motion of the chain, thus causes idler gears 497 and gears 498 to rotate. As gears 498 rotate, so do planetary members 322.

Various other types of driving mechanisms for rotary systems within the scope of the present invention are possible.

The Mathematical Assumptions

In each of the above embodiments the tangential velocity of each object-pick up member will be at or approach zero at the vertices of its trajectory. This is achieved through selection of a specific arrangement of mounting distances for planetary axis; moon axis; and pick-up member relative to a sun axis, and relative rates of rotation of carrier; planetary member and moon member. This selection may be even more clearly understood by reference to the following mathematical equations which are valid for the above embodiments:

Where,

E.sub.uv /2=distance from the sun axis 30/330 to the circumferential are created by the pick up point (eg. suction cup) of the pick-up member 26a when positioned at the vertices of its trajectory;

D/2=distance from the sun axis 30/330 to the planetary axis 32a/332a;

e=the distance from the planetary axes 32a/332a to the moon axes 34a/334a;

V.sub.t =tangential velocity at a vertex of the path of the pick-up member;

The physical significance of these variables is shown is FIGS. 4 and 11a.

The tangential velocity of the pick up point of a pick-up member V.sub.t at a vertex of the path is calculated as follows:

In order to obtain a minimal tangential velocity of pick-up member 26a at these vertices, E.sub.nv, D, e, .omega..sub.1, .omega..sub.2 and .omega..sub.3 must be chosen such that V.sub.t =0 in the above equation.

Thus, in Embodiment 1 (see FIG. 2a):

Setting V.sub.t =0; and choosing .omega..sub.2 =-3.omega..sub.1, and .omega..sub.2 =-.omega..sub.3 yields

In Embodiment 4 (see FIG. 11a):

Setting V.sub.t =0; and choosing .omega..sub.2 =-6.omega..sub.1, and .omega..sub.2 =-.sub.3

In both embodiments, D may be calculated by noting:

It will be understood by a person skilled in the art that many different variations are possible. Depending on the choice of sizes of the carrier and the planetary members, it is possible to construct a rotary feeder with an arbitrary number of carrier members. These carrier members may be adapted to rotate at any rate. By choosing the proper length of mounting shafts and/or extension members it is possible to balance the rotary feeder so that these pick-up members reach a minimum tangential velocity at the vertices of their trajectory(ies).

It will be further understood that the invention is not limited to the illustrations described and shown herein, which are deemed to be merely illustrative of the best modes of carrying out the invention, and which are susceptible to modification of form, size, arrangement of parts and details of operation. The invention, rather, is intended to encompass all such modifications which are within its spirit and scope as defined by the claims.