Atomizing or Metering Pump

The invention relates to an atomizing or metering pump with a pump casing and an operating pusher displaceable relative thereto, cooperating projections and recesses being provided on the pump casing and the operating pusher.

Such a pump is known from German Utility Model No. 79 01 055, in which the cooperating projections and recesses are used for preventing any twisting of the operating pusher with respect to the pump casing.

The problem of the invention is to further develop an atomizing or metering pump, so as to facilitate the use and increase the reliability thereof.

This problem is solved by the present invention as disclosed and claimed.

Preferably the projections and recesses for the reciprocal locking of pump casing and operating pusher can cooperate in at least one predetermined rotation position for preventing operation of the pup. This prevents operation of the pump during transportation, or in an unauthorized manner, e.g. by children. This is particularly important if it is a pump for pharmaceutical products. The term "metering pump" covers pumps for dispensing all flowable substances, such as liquid, gel-like or pasty substances.

The projections and recesses can at least partly be undercut and secure the operating pusher in a predetermined rotation position, so that it cannot be removed from the pump. Thus, in this position, which preferably coincides with the position preventing operation, it is ensured that the operating head cannot be removed from the pump piston rod which, apart from causing a possible loss of the operating pusher, could also lead to a contamination of the outlet passage. In all the described embodiments, the projections or recesses, which also covers shoulders, steps, stop faces, etc., can either be provided on the operating pusher, or on the pump casing.

It is particularly advantageous if the projections and recesses cooperate with one another for releasing a pump path, which differs as a function of the rotation position. Thus, it is possible to adjust the metering or atomizing quantity. For this purpose a projection can cooperate with a curved or preferably stepped surface. As a result of the step arrangement, there is no need for fixing the quantity setting during operation, which could otherwise be automatically changed by the action of the curved portion. The adjustment could, for example, result from a twisting of the operating pusher with respect to the pump casing. The rotary part can also be a ring mounted on the operating pusher, or preferably on the pump casing. Advantageously on the ring mounted with limited rotational freedom on the pump casing and in the adjacent area of the pump casing with respect to the operating pusher, there are axial slots which can be made to align with one another and into which can pass internal projections of the operating pusher, which overlap in this area.

A separate ring, mounted in rotary manner on the pump casing is also advantageous when securing against operation and/or removal of the operating pusher, because then in the predetermined safety rotational position the operating pusher can be rotated into a given position, e.g. for packaging purposes, independently of the position of the pump on the container, which has e.g. taken place accidentally when threading the pump onto the container. For example, this is important if both the container and the operating pusher have a non-rotationally symmetrical shape, e.g. a flat or angular container with an operating pusher having a lateral projection.

Particular preference is given to an embodiment, in which the at least one projection cooperates with a recess extending over part of the circumference and whose two ends limit the movement of the projection in the recess. In the vicinity of one end of the recess there is an axial slot permitting the axial movement of the projection.

The invention is described in greater detail hereinafter relative to non-limitative embodiments and with reference to the attached drawing, wherein show:

FIG. 1 a vertical section through an operating pusher and part of a pump casing screwed on to a container.

FIG. 2 a corresponding view of the same construction in another operating position.

FIG. 3 a section along line III--III of FIG. 2.

FIG. 4 a partial sectional side view of the operating pusher and pump casing of another embodiment.

FIG. 5 a perspective view of the lower edge of an operating pusher with slots and projections formed therein.

FIG. 6 a partial sectional view of the operating pusher according to FIG. 5, viewed from below, with a sectional part of the pump casing.

FIG. 7 a vertical partial section through the operating pusher and pump casing of a further embodiment.

FIG. 8 an axial section through another embodiment of the invention,

FIG. 9 a top view on the holding means according to FIG. 8,

FIG. 10 a partial sectional side view of a further embodiment of the invention.

FIGS. 1 to 3 show a metering or atomizing pump 11, which is screwed on to a container 12. Pump 11 has a pump casing 13, on which is provided a pump cylinder (not shown) partly projecting into the container and having a single-acting piston pump. A piston rod 15 of the pump projects upwards out of the pump casing and on to it is pressed an operating pusher 14, which has an outlet channel 27 connected to the outlet channel of the hollow piston rod. Channel 27 in a delivery pipe projects laterally over the operating pusher, which is constructed as an inverted cup-shaped part. The bottom of the cup is formed by the operating pusher face 16 on which the user presses for operating the pump in the direction of arrow 28.

The cylindrical casing 17 of the operating pusher has, in the present embodiment, on its inner face four projections in the form of axially directed ribs. Whilst the internal diameter of casing 17 is such that it overlaps an upper cylindrical area 21 of the pump casing, the projections 19 are dimensioned in such a way that they normally rest on a step 29 in area 21. In the same arrangement as ribs 19, there are four recesses 20 in area 21 and are shaped like longitudinal slots, which serve to receive the projections.

A ring 22 having a substantially L-shaped configuration is mounted in circumferentially rotary, but axially non-displaceable manner in an annular slot 24 of the pump casing. The outer face of its axially directed L-leg leads without transition to area 21 and also has recesses 23 in the form of axial slots which, through the rotation of ring 22, can be aligned with recesses 20 (cf. FIG. 1). Marks 25, corresponding to two ring positions, are provided on the outwardly projecting L-leg of the ring and on the adjacent area of pump casing 13. The rotation of the ring can be limited in these positions by arbitrarily-placed stop members (not shown). It is also possible to associate resilient catches with these two positions.

The operation of the construction according to FIGS. 1 to 3 is as follows. In the position of FIG. 1, the pump is set for full stroke (indicated by the mark "1"). The two recesses 23 are aligned. If the operating pusher 14 is now depressed, projection 19 enters the aligned recesses 20, 23 and engages against the lower shoulder 30 of ring 22, which corresponds to the full pump stroke.

In the position according to FIG. 2, the half-stroke is set by rotating ring 22. Recesses 20 and 23 are not aligned, so that projection 19 can only pass through recess 20 and then engages with the upper end face 26 of ring 22. FIG. 3 also shows this position with recesses 20, 23 displaced with respect to one another.

It is also pointed out that in this construction, the pump can be completely blocked, in that the operating pusher 14 is so turned relative to pump casing 13 that projections 19 rest on step 29 when not aligned with recesses 20. This represents the safety position against undesired operation of the pump.

FIG. 4 shows an embodiment, which permits a setting in several stages (0, 1/4, 1/2, 3/4, 1) (marks 25a). For this purpose a ring 22a is provided having on its outer circumference a recess 23a in the form of a depression in the cylindrical wall of the ring, whose lower face 26a rises in the form of a five-step staircase. In FIG. 4, the pump is shown in position "O", in which a projection 19a on the inner face of the cylindrical casing of operating pusher 14a rests on the top step. Here, recess 23a is overlapped by a web 31, so that in the zero position, projection 19a secures the operating pusher against any axial movement, both in the operating direction, and also against the removal of said pusher.

To prevent any tilting of the operating pusher, the same arrangement can also be provided on the opposite side.

In the case of a setting to any random desired stroke value, the operating pusher can be pressed down to such an extent that projection 19a rests on the corresponding step 26a.

FIGS. 5 and 6 show a construction in which, in the vicinity of a lower edge 32, the operating pusher 14b has a system of recesses and webs, shaped with corresponding projections 19b on pump casing 13 or on a ring mounted thereon.

The system of recesses is arranged on the inner circumference of casing 17b of operating pusher 14b and comprises four identical system units. Each contains an axially directed slot 33, recessed into the inner wall of casing 17b and on to which follows a somewhat less recessed circumferential recess 34 in the vicinity of lower edges 32. This is open towards edge 32 and only at its end remote from slot 33 is it covered by a web 35 is such a way that a channel-like slot is formed in this short area, where there is a depression 36.

The width and depth of the four projections 19b are defined in such a way that they can easily pass into recess 34 under slight contact pressure, whilst they can pass without hindrance into slot 33, which is even deeper than recess 34. In the latter position, the pump can be operated. However, if the operating pusher 14b is rotated into the inoperative position, so that the projections 19b pass into recess 34, then the pump is locked against operation. On further rotating up to end stop 37, the projections 19b enter the channel-like portion of recess 34, so that web 35 ensures that the operating pusher 14b cannot be removed. Depressions 36, together with projections 19b, form catches, which resiliently fix the operating pusher in this position. The rotation direction is selected in such a way that on screwing the pump, which is provided with a screw thread 40 (FIG. 7) on to a container of the operating pusher, it automatically assumes this safety rotation position, as shown in FIG. 6. Thus, immediately after application of the pump to the container, the pump is secured for transportation purposes.

FIG. 7 shows a construction, which operates with an operating pusher 14b according to FIGS. 5 and 6. In this case, the pump casing 13c contains pump cylinder 38 as a separately inserted part. However, the term pump casing generally covers all parts of the pump, which are fixed with respect to the container, or with respect to which the operating pusher moves axially.

A ring 22c is inserted in an annular edge recess 39 on pump casing 13c and is secured against axial movement by an annular bead 40 snapping into a corresponding slot, whilst its rotary movement is decelerated in a controlled manner. Four projections 19b cooperating with recesses 33, 34 are shaped on to the outer circumference of the ring, which is flush with the outer circumference of pump casing 13c. The arrangement of ring 22c, which can be rotated against a certain resistance, makes it possible for the operating pusher 14b to be turned into a random position, and from said basic position to perform the function described relative to FIGS. 5 and 6 (pump operation/blocked operation/safety position).

This is important in order e.g. to turn the delivery pipe 18 into a position suitable for transportation, but at the same time axially securing the operating pusher. However, in place of the delivery pipe, it would also be possible to use an atomizing nozzle, or some other construction of the operating pusher. FIGS. 8 and 9 show a very advantageous embodiment of the invention. Pump structure 11c comprises a tubular holding means 13c for the pump cylinder 38c or pump unit which can be inserted into the holding means 13c resting against an inner ring shoulder provided axially adjacent to a neck-portion 21c forming an end or front face 32c of the holding means 13c. Operating pusher 14c is provided with a cylindrical jacket 17c. In assembled condition jacket 17c overlaps neck 21c already in the resting or initial position and is axially displaceable with respect to the neck 21c. Pusher 14c and neck 21c form abutment means controlling the length of pump stroke. until in its the utmost end position it rests against ring shoulder 30c protruding radially over the circumference of neck 21c and formed by the end face of the part of holding means 13c bearing a thread 40c for fixing the holding means 13c on a correspondingly threaded container neck. The end face of jacket 17c is planar and rectangular to pump axis 1 and has a outer diameter slightly smaller than the outer diameter of ring sholder 30c.

Neck 21c has an outmost circumferential surface 43, said surface 43 in cross-sectional view being bordered by circles around the pump axis 1 and advantageously being substantially of cylindrical shape all over the axial length of neck 21c. In several regions the circumference of neck 21c is profiled by recesses, steps and grooves, forming control means coacting with two diametrically opposite web-like projections 19c on the cylindrical inner face of jacket 17c. In its initial, and any operation position, inner face of jacket 17c has a slight radial distance from surface 43 of neck 21c, thereby permitting a slight resilient deformation of jacket 17c. Projection 19c extends to end or front face 44 of jacket 17c and is reduced in width to this end to better locate into axial grooves 2,4 of neck 21c when operating pusher 14c is manually displaced along pump axis 1 for effecting a pump stroke. Grooves 2,3,4 are of different length, whereby the length is stepwise increased from a shortest groove 2 in one circumferential direction to a longest groove 4. Grooves 2,3,4 are offset from front face 32c of neck 21c, thereby forming receiving or immersing ends 10 for receiving projection 19c, said immersing ends 10 being offset with respect to the front face 32c by equal distances, this distance being about equal to the axial extension of the shortest groove 2. Adjacent to the immersing ends 10 of grooves 2,3,4 there is an arched path 34c extending from front face 32c to a ring shoulder penetrated by immersing ends 10 of grooves 2,3,4 and therefore divided into ring portion shoulders 29c. Ring portion shoulders 29c extend perpendicularly to pump axis 1 from the circumference of arched path 34c to outer surface 43. In the direction ring portion shoulders 29c extend in one direction to one outermost groove 4 which in the embodiment shown is the longest groove 4. In the opposite circumferential direction corresponding last ring portion 29c extends beyond the corresponding outermost groove 2, which in the embodiment shown is the shortest groove 2. Circumferential extension of all ring portion shoulders 29c is about the same. The width of each groove 2,3,4 is only slightly larger than the width of projection 19c, thereby guiding projection 19c positively during a pump stroke. Each groove 2,3,4 is bordered by an end face 26c rectangular to pump axis 1 and positioned on the end of groove 2,3,4 remote from immersing end 10 and front face 32. End faces 26c are stepwise displaced in axial direction with respect to each other, the end face of the longest groove 4 being formed by ring shoulder 30c. The end faces 26c and ring shoulder 30c provide stop and/or abutment shoulders for the tapered end of projection 19c. The bottom faces 41 of grooves 2,3,4 have a slightly bigger radial distance from pump axis 1 than corresponding radial inner face of projection 19c in not assembled condition, thereby providing a contact of this radial inner face with bottom faces 41 under a slight spring-loaded pressure and therefore providing a certain friction between projection 19c and control means of neck 21c during a pump stroke. On the other hand it is also possible to avoid this friction by providing a slight radial play between the radial inside face of projection 19c and the bottom face 41 in operation.

The grooves 2,3,4 are elongated along the entire arched path 34c, thereby dividing arched path 34c into connecting portions 42 positioned between flat end portions 5 of grooves 2,3,4. The bottom faces of flat end portions 5 are formed by elongations of bottom faces 41 and have the same radial distance from pump axis 1 as the latter. The depth of flat end portions 5 may be far less than one millimeter. The depth of grooves 2,3,4 and therefore of end faces 26c may be about one millimeter, the radial extension of ring portion shoulder therefore being of a value between the depth of grooves 2,3,4 and the depth of flat end portions 5, this extension being larger than the depth of flat end portions 5. Bottom faces 41 of grooves 2,3,4 and flat end portions 5 may be cylindrically arched around pump axis 1.

At least one side face of each flat end portion 5 forms a step-like catch-member 7 which has to be overcome by projection 19c positioned in respective flat end portion 5 and upon rotation of operating pusher 14c relative to neck 21c. In this case only upon a certain minimum rotation force applied to operating pusher 14c, projection 19c will be resiliently pushed back and will be able to jump on the corresponding connecting portion 42 of arched path 34c, thereby avoiding inadvertently turning of the operating pusher 14c out of the respective adjusted positioned corresponding to a predetermined output volume of the pump structure 11c. While rotationally sliding on the correspondingly connecting portion of arched path 34c, projection 19c is in higher friction contact with neck 21c than in the case of engaging any flat end portion 5 or groove 2,3,4, since the radial distance of each connecting portion 42 from pump axis 1 is slightly larger than the corresponding distance of bottom faces 41. In initial position of operating pusher 14c front end of projection 19c and end face 44 are positioned substantially in the plane of the ring portion shoulders 29c, whereby during movement of projection 19c out of the groove 2,3,4 and flat end portions 5 operating pusher 14c is prevented from any axial movement in the direction of the pump stroke. When arriving at flat end portion 5 upon turning, projection 19c will jump back into flat end portion 5, which can be felt by the user, and therefore securely indicates correct positioning.

Both circumferential ends of arched path 34c are provided with circumference stop means for projection 19c, these stop means being formed by stop faces 9, 37c. At the end adjacent to one outermost groove 4 which in the case shown is the longest groove 4, the stop face 9 is formed by the lateral groove face remote from the adjacent groove 3 and elongated to front face 32c. Therefore the corresponding flat end portion 5 is only provided with one catch member 7. The other stop face 37c is remote by a distance from the next adjacent groove 2, this circumferential distance being about the same distance between adjacent grooves 2,3,4. Directly adjacent to this stop face 37c the arched path 34c is provided with an axial flat groove 6 of equal dimensions like the flat end portions 5 except that this flat groove 6 does not continue into a groove but ends at the corresponding ring portion sholder 29c. Therefore there is another catch member 7 resiliently catching the projection 19c while abutting against stop face 37c. When projection 19c rests against stop face 37c and in flat groove 6, operation pusher 14c is in a non-operative security position where projection 19c rests axially against corresponding ring portion shoulder 29c extending up to stop face 37c. All grooves 2,3 between the outermost groove 4 and flat groove 6 are provided with two catch members 7 each, one on each side of the corresponding flat end portion 5. The flat end portions 5 have the same width as the grooves 2,3,4.

Projection 19c may extend to the inner end face of cap-like jacket 17c, this end face being provided with e.g. four ribs equally distributed around pump axis 1, so that in the end position of operating pusher 14c only these ribs will contact front face 32c. The inner circumferential surface of jacket 17c may be provided with a number of axial ribs of lesser heights than projection 19c, these ribs providing the only contact faces of jacket 17c for contacting circumferential surface 43 of neck 21c.

As can be seen in FIG. 9 the grooves 2,3,4 and the stop faces 9, 37c provide a groove unit extending over slightly less, e.g. about 40.degree. less, than 180.degree. around the pump axis 1. There are provided two such groove units diametrically opposite to each other, equal grooves 2,3,4, stop faces, ring portion shoulders, connecting portions etc. lying each symmetrically to a common axial plane of pump axis 1.

The operating pusher 14c is rotatably mounted on piston rod (not shown) by means of a tube section positioned inside nozzle 18c, forming part of the outlet channel 27c and plugged onto piston rod in a rotatable manner. Tube section 45 extends into jacket 17c, the free end of tube section 45 being positioned inside jacket 17c and remote from front face 44. At least one mark 25c may be provided on the outside circumference of jacket 17c, each mark 25c preferably being in alignment with one corresponding projection 19c. Corresponding markings may be provided on the outside of holding means 13c near ring shoulder 30c.

As FIG. 10 shows, means may be provided to secure operating pusher 14d in any rotational and axial position against movement opposite to pump stroke movement according to arrow 28d, thereby preventing withdrawal and/or plugging off operating pusher 14d from the remaining pump structure 11c. There is e.g. an undercut recess 31d in stop face 37d remote from front face 32d and in continuation of corresponding ring portion shoulder 29d, the recess 31d being adapted to receive projection 19d which in this case is not web-like but has an extension in the direction of pump axis 1d which is only slightly smaller than the corresponding extension of recess 31d. By means of recess 31d operating pusher 14d can be prevented from withdrawal in the initial position when operating pusher 14d is turned so far that projection 19d is received by recess 31d.

In the case of groove 4d there are two opposite recesses 36d, 36'd in both side faces of groove 4 and in lateral continuation of the corresponding end face and/or the ring shoulder 30d, both recesses being adapted to alternately receive projection 19d, thereby locking operation pusher 14d in both axial directions in the utmost axial operating position. Each recess, whether on the side of groove 4d remote from the next adjacent groove or on the opposite side may be provided with a catch either resiliently or positively securing projection 19d in the corresponding locking position. In the case of positively secured engagement there is a catch protruding towards the end face, or the ring shoulder 30d, respectively, over the inside face of recess 36'd opposite to this end face and bordering and inlet opening for projection 19d for moving into recess 36'd. To release operating pusher 14d, which is spring-loaded against the pump stroke direction according to arrow 28d, operating pusher 14d has to be pushed slightly in the direction of the pump stroke until it contacts ring shoulder 30d, whereupon it can be turned into groove 4d. In the other case the recess 36d has a tapered side face opposite to ring shoulder 30d thereby providing an inlet opening for projection 19d, said inlet opening having a slightly smaller extension parallel to pump axis 1d than the rest of the recess 36d. Therefore by turning projection 19d out of recess 36d into groove 4d the operating pusher 14d will automatically be moved against its spring-loading in the corresponding axial direction. Each of the other grooves not shown in FIG. 10 may as well be provided with one or two opposite locking recesses adjacent to their end faces, thereby enabling the operating pusher 14d to be locked in any operating end position.