Cartridge-Type Dispenser Gun

This invention relates to a dispensing gun of the type holding a cartridge to dispense a substance from it. Such gun is conventionally used for caulking and can be used for greasing machinery and for frosting cakes.

The dispenser guns of the cartridge type have so far been made to operate with a straight or rectilinear cartridge, using straight line displacement of the piston pushing the substance out of the cartridge. In such dispensing guns, the force to push the material out of the cartridge is limited by the leverage that can be given by the actuation lever. Another disadvantageous aspect comes from the linear operation and construction requiring very substantial space to be satisfactorily operated and even to be used. With such guns of linear operation, the piston is retracted by hand, often requiring a substantial expense of energy.

It is a general object of the present invention to provide a cartridge-type dispenser gun that requires less space for operation compared to the dispenser gun of the linear type.

It is another general object of the present invention to provide a cartridge-type dispenser gun that provides a cartridge-type dispenser gun that provides a better leverage or multiplication of the force deployed by the user and thus requires less force to push the substance out of the cartridge.

It is a further general object of the invention to provide a cartridge-type dispenser gun that provides a more steady piston pressure.

It is a more specific object of the present invention to provide a cartridge-type dispenser gun that uses a longitudinally arc-shaped cartridge to be of more compact operation and construction.

It is another object of the present invention to provide a cartridge-type dispenser gun that compactly and efficiently uses rotary movement and multiplication of forces for easier operation and dispensing of the substance out of the cartridge.

It is a further object of the present invention to provide a cartridge-type dispenser gun wherein retraction of the piston is effortlessly done by spring action.

The above and other objects and advantages of the present invention will be better understood with reference to the following detailed description of preferred embodiments thereof, which are illustrated, by way of example, in the accompanying drawings, in which:

FIG. 1 is a front view of a cartridge-type dispenser gun according to one embodiment of the invention manually operated by a lever;

FIG. 2 is a cross-sectional view of the dispenser gun of FIG. 1;

FIG. 3 is a partial view of FIG. 2, particularly indicating the mode of operation of certain parts of the dispenser gun of FIGS. 1 and 2;

FIG. 4 is a front view with parts broken away of a cartridge-type dispenser gun according to a second embodiment of the present invention; and

FIG. 5 is a side view with parts broken away of the dispenser gun of FIG. 4 .

The cartridge-type dispenser gun illustrated in FIGS. 1, 2, and 3 includes a body 10 defining a longitudinally arc-shaped cartridge chamber 11 and a piston rod chamber 12. The main portion of the body 10, defining the chambers 11 and 12, has the general form of a sector and is integrally formed with a portion 13 forming a fixed handle. Coaxial with the sector-shape portion, there is mounted a ratchet wheel 14, of a pawl and a ratchet wheel assembly. The ratchet wheel 14 is rotatively mounted in the body by stub axles, one of which, namely stub axle 15, outwardly projects from the body 10 on one side of it. A manually-controlled handle, or lever 16, is secured on the stub axle 15 by a setscrew 17 for bodily rotation with the ratchet wheel 14. The latter is provided with teeth along a portion of its circumference. A pawl 18 is pivoted at 19 parallel to the axis of the ratchet wheel 14. The pawl is formed with a projection to engage the teeth of the ratchet wheel and with another projection through which is engaged the stem of a push button 20. A compression spring 21 releasably biases the pawl 18 into engagement with the teeth of the ratchet wheel 14. Thus, as the lever 16 is progressively pivoted in the direction of the arrow 22 toward the fixed handle 13, the ratchet wheel 14 bodily rotates with it and the pawl 18 stepingly engages the teeth of the ratchet wheel.

A piston 23 is displaceable longitudinally of the cartridge chamber 11 inside the cartridge 24 to expel its flowable substance through its nozzle 25. A piston rod 26 is secured to the piston 23 at its outer end and to the ratchet wheel 14 at its inner end. The piston rod 26 includes a radially-projecting inner end portion 27 and a longitudinally arc-shaped outer end portion 28 extending co-axial with the longitudinally arc-shaped axis of the cartridge chamber 11 and cartridge 24. Guide rollers 29 are arranged in the body 10 to guide the portion 28 relative to the cartridge 24 to properly push the piston in it. A spring-guiding pin 30 projects in the body 10 parallel to the outer end portion 28 and is arcuately aligned with an aperture 31 into which it engages when the piston 23 progresses into the cartridge chamber 11. A return spring 32 is engaged around the spring-guiding pin 30 to act in compression against the piston rod 26 to retract the piston 23 when the pawl 18 releases the teeth of the ratchet wheel 14 upon pushing of the push button 20.

The cartridge-type dispenser gun illustrated in FIGS. 4 and 5 is provided with elements similar to some elements of the aforedescribed dispenser gun and those elements will be identified by the same reference numerals as in FIGS. 1, 2, and 3.

The dispenser gun in FIGS. 4 and 5 includes a body 40 having a main portion defining a longitudinally arc-shaped cartridge chamber 41 and a chamber 42 for a clutch and associated drive and control elements. The body 40 is formed with a depending fixed handle portion 43. As in the embodiment of FIGS. 1, 2, and 3, the dispenser gun of FIGS. 4 and 5 includes a ratchet wheel and pawl assembly including the elements 14, 18, 19, 20, and 21 and also includes the piston and piston rod assembly including the elements 23, 26, 27, 28, 29, 30, 31, and 32. The ratchet wheel 14 is fixedly mounted on a main shaft 44 that is journalled at its opposite ends in the body 40 and extends transversely of it.

A manually-controlled lever 45 is pivoted on the main shaft 44 and has a handle portion 46 outwardly extending from the body 40 and pivotable, as shown by the arrows 47, toward the fixed handle portion 43. The lever 45 is adapted to control a clutch mechanism that includes three frictional contact wheels 48, 49, and 50. The latter will be better described in details later.

An electric motor 51 is secured against one side of the body 40 and is connected to drive the sprocket wheel 14, as will now be described. The motor 51 is controlled by an on-off switch 52. The electric motor drives a pinion 53 in meshing engagement with a larger gear 54. The latter bodily rotates with a frictional contact wheel 55. A sector 56 of a frictional contact wheel is fixedly secured on the main shaft 44 to bodily rotate with it and, thus, also with the ratchet wheel 14.

The pivoting of the lever 45 about the shaft 44 allows to either engage wheel 48 or 49 with the wheel 55 or to engage neither when the lever is in an intermediate position; that is, with the frictional contact wheel 55 positioned between the wheels 48, 49, and touching neither. The innermost position of the lever 45 causes engagement of the wheel 48 with the wheel 55, and this drives the wheel sector 56 and the ratchet wheel 14 to move the piston forward and, thus, expel the substance from the cartridge. On the other end, the outermost position of the lever 45 causes engagement of the wheel 49 with the wheel 55 and, through wheel 50, this drives the wheel sector 56 in reverse to retract the piston from the cartridge in conjunction with release of the pawl by the push button 20, as aforementioned with reference to the manually-operated dispenser gun. When the lever 45 is in intermediate position, neither of the wheels 48 and 49 is engaged and the clutch mechanism is in neutral or idle drive position.

A compression spring 57 engages the lever 45 and urges the same toward the reverse drive position, such that no substance is dispensed from the cartridge unless the lever is intentionally squeezed toward the fixed handle 43. The lever 45 is pivotally connected to the fixed handle portion 43 by a link 58. A stopping needle 59 is selectively rotatable in the fixed handle portion 43 by a setting lever 60. The stopping needle 59 may thus be angularly set, as shown in FIG. 5, to stop the link 58 in its intermediate position, thus also holding the lever 45 in its intermediate position under the bias of the spring 57.

It must be noted that the wheels 55 relative to the wheels 48 and 49, the wheels 48 and 50 relative to the wheel sector 56 and the pinion 53 relative to the gear 54 may be diametrically related to provide very substantial leverage or multiplication, thus achieving a very steady displacement of the piston and flow of the substance out of the cartridge.