Protector cap and wiper for dispenser discharge orifice

Abstract: The finger actuated plunger (10) of a dispenser has a protector cap (23) pivotally mounted thereon and normally disposed for covering the discharge orifice (22). The cap is pivotally movable relative to the head upon application of finger force to the cap in the direction of plunger head reciprocation for uncovering the orifice. The cap (23) is resiliently urged into its normal orifice-covering position upon removal of the applied finger force.

Description: This invention relates generally to a manually operated dispenser having a reciprocable plunger head containing a discharge orifice through which product is dispensed upon head reciprocation. More particularly, the invention relates to a protector cap pivotally mounted on the plunger head, normally covering the discharge orifice during non-use, and automatically uncovering the orifice at the initiation of manual reciprocation of the head. Manually actuated pump dispensers are well known for dispensing a variety of products upon finger actuation of a plunger head which reciprocates the pump piston traveling within a pump cylinder for pressurizing the product and discharging it through a discharge passage located in the head which terminates in a discharge orifice. The products to be dispensed, as by spraying, include hair sprays and other resinous materials which, upon drying, upon exposure to the atmosphere, tend to clog the spray discharge orifice. Clogging interferes with the free flow of discharge by causing sputtering and uneven spray patterns. Protector caps and covers have been devised to prevent the drying out of the discharged material in the discharge spout or orifice and to prevent its contamination. The known caps and covers employed for this purposes are, however, rather cumbersome. Typical prior art protector caps are shown in DE-A-2655777 and FR-A-1572537. The present invention is characterised in that the protector cap is pivotally mounted on said plunger head and has an annular wall of an outer diameter substantially flush with the outer diameter of the adjacent portions of the cylindrical wall, the cap in its entirety, including the annular wall, being pivotally movable relative to the head upon application of finger force to the cap in the direction of pump reciprocation for uncovering the orifice, means being provided for urging the cap into its normal position covering the orifice upon removal of the applied finger force. The upper portion of the cylindrical wall of the head preferably has an annular external recess for receiving the annular wall of the cap, such that the outer diameter of the cap annular wall is substantially flush with the outermost diameter of the head cylindrical wall. Furthermore, the cap annular wall preferably has an internal projection in alignment with the orifice in the covering position for wiping the orifice clean when uncovered in the event of any accumulation of dry product at the orifice. The invention will be better understood from the following detailed description thereof when taken in conjunction with the accompanying drawings, wherein: Figure 1 is a front elevational view of one embodiment of the invention, showing the protector cap pivotally mounted on a dispenser plunger head; Figure 2 is a view taken substantially along the line 2-2 of Figure 1 with the plunger head shown mounted on the upper portion of a pump body shown in section; Figure 3 is a view similar to Figure 2, showing the discharge orifice uncovered during use; Figure 4 is a front elevational view of another embodiment of the invention showing the protector cap pivotally mounted on a dispenser plunger head; Figure 5 is a view taken substantially along the line 5-5 of Figure 4, partly in section; Figure 6 is a view similar to Figure 5 showing the discharge orifice uncovered during use; and Figure 7 is a top plan view of the plunger head, with the protector cap removed, taken substantially along the line 7-7 of Figure 5. Turning now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, a plunger head 10 for a finger actuated pump sprayer is shown in Figure 2 as typically mounted on a pump dispenser body 11, cooperating retention beads 12 and 13 respectively on the head and the body cooperating in a known manner to prevent separation of the parts. The body has an upper transverse wall 14 supporting a fixed cylinder 15 in communication with a valved inlet (not shown) from which a dip tube (not shown) extends into the product within the container (not shown) to which body 11 is mounted as in a known manner. A return spring 16 acts between wall 14 and an under-surface 17 of the head, and a hollow piston 18 depends from the head for reciprocation within the pump cylinder. A discharge passage 19 communicates with the hollow piston, and a valve cup 21 is mounted within the head in communication with the discharge passage. The discharge passage terminates in a discharge orifice 22 located in the valve cup. Thus, upon manual reciprocation of the plunger head along its central axis, product is discharged during each compression stroke through the discharge orifice, as known in the art. A protector cap 23 of the invention is pivotally mounted on the plunger head, such as by means of a depending plate spring 24 received within a slot 25 located in the upper surface 26 of the plunger head. The cap as an upper wall 27 forming a bearing surface for the finger of the operator in a manner to be more fully described hereinafter. An annular wall 28 depends from wall 27 and, as seen in Figures 1 and 2, has a wall portion 29 covering the discharge orifice in the normal position of the cap. The cap is apertured as at 31 in vertical alignment with discharge orifice 22. In addition to or in lieu of plate spring 24, an up-standing plate spring 32 may be provided on plunger head 10 adjacent spring 24 and extending into a slot 33 located in the underside of the cap. In operation, application of finger force against upper watt 27 of the protector cap, in the direction of the arrow of Figure 2, pivotally moves the cap downwardly with spring 24 and/or spring 32 acting as a pivot. At the same time, aperture 31 in the cap is moved into alignment with discharge orifice 22 for thereby uncovering the orifice. Continued application of the finger force applied to the cap, in the direction of plunger reciprocation, depressses the plunger head relative to dispenser body 11 to effect the spray discharge of product through the uncovered discharge orifice and the aligned aperture 31, as illustrated in Figure 3. The slight spacing between upper wall 27 and uppermost surface 34 of the plunger head facilitates pivotal movement of the cap from its Figure 2 to its Figure 3 position as wall 27 is brought to substantially bear against surface 34. When the desired amount of product has been dispensed upon each pressure stroke of the plunger, the applied finger force is removed, allowing the plunger and the cap to return to the upwardly extended position of the plunger shown in Figure 2, as assisted by return spring 16, as known in the art. Removal of the applied finger force automatically returns the cap to its Figure 2 position from that of Figure 3 as resiliently urged by the unbending and flattening of spring 24 and/or spring 32 into the orifice-covering position of Figure 2. In the orifice-covered position of Figure 2, the orifice is closed to the atmosphere, thereby avoiding possible clogging of discharge passage 19 and of discharge orifice 22 during especially prolonged periods of non-use of the dispenser. Such prolonged exposure to air would otherwise adversely affect the quality of the discharge or other physical characteristics. In accordance with another feature of the invention, any accumulation of dried product at or in the discharge orifice is removed and is further prevented by the provision of a small projection 35 on the inner surface of annular wall 28 of the cap. As shown in Figure 2, this projection is in alignment with the discharge orifice and may slightly project into the orifice in the orifice-covering position. Upon downward pivotal movement of the cap to the Figure 3 position, the projection simply wipes the orifice and its vicinity clean while removing any dried product as may have accumulated. As seen in Figures 1 and 2, the overall size of the cap is essentially the same as that of the plunger head, giving a neat and attractive appearance and avoiding the appearance of an otherwise unsightly oversized cap. For this purpose, cylindrical wall 36 of the plunger is cut away as at 37 along a plane inclined relative to the central axis of the head. An external annular recess 38 is thus formed of a depth essentially equal to the thickness of annular wall 28 of the cap. The outer diameter of wall 28 is therefore substantially flush with the major diameter of cylindrical wall 36, while recess 38 permits the cap to pivotally move to its Figure 3 position without interference. Another embodiment of the invention is illustrated in Figures 4 to 7, in which a protector cap 39 is pivotally mounted on plunger head 10 for rearward rocking movement into an orifice-uncovered position compare to the forward rocking movement of Figures 1 to 3. Plunger head 10 of Figures 4 to 7 is essentially the same as that of Figures 1 to 3 for mounting on body 11, except for the upper external recess formed thereon to accommodate cap 39. Protector cap 39 is pivotally mounted on the plunger head by the provision of a pair of spaced plate springs 41 received within corresponding slots 42 located in the upper surface of the head. Annular wall 43 of the cap covers the discharge orifice in the Figure 5 position for closing the discharge to the atmosphere to avoid drying of product during especially prolonged periods of non-use, which may cause orifice clogging. Upon application of finger force, along the arrow of Figure 5, in the direction of plunger reciprocation, the cap pivots at springs 41 by rocking rearwardly such that its annular wall 43 uncovers the discharge orifice to permit discharge through an unclogged orifice during each pressure stroke of the plunger. Removal of the applied finger force returns cap 39 to its Figure 5 position as resiliently urged by the unbending of springs 41. Annular wall 36 of the plunger head is cut away as at 44 so as to provide an annular recess 45 at the upper portion thereof of a depth substantially equal to the thickness of annular wall 43. The cutaway section lies in a transverse plane through approximately 180° of the plunger head, and inclines downwardly therefrom,, as seen in Figures 5 and 6, to accommodate the rearward rocking motion of the cap without interference. It should be pointed out that the spring force of the resilient means employed for both embodiments must be less than the force required to depress the plunger against the combined action of return spring 16 and the hydraulic pressure in the pump chamber of the dispenser. This assures that the protector cap will be pivoted to its orifice-uncovered position momentarily before plunger depression such that the discharge orifice is uncovered before product issues from the discharge orifice. And, the aperture-free protector cap of the Figures 4 to 7 embodiment likewise has a projection 37 seated in or at the discharge orifice in the Figure 5 closing position for assuring a clog-free orifice and for wiping the orifice and its vicinity of any accumulated dried product as the cap is pivotally moved to and from its Figure 6 position. Moreover, it can be seen that the plate springs of both embodiments lie within the confines of the protector caps, i . e ., spaced inwardly of the annular wall thereof. This tends to further improve upon the appearance of the cap/plunger head assembly. And, although both embodiments have been described with reference to plate springs, other resilient means can be employed without departing from the scope of the invention. Operation of the protector cap of the invention requires no special instructions for the user. Consequently, neither the plunger nor the cap need be marked with indicia to acquaint the user for its operation. Finger force is simply applied to the upper surface of the protector cap as in any other finger actuated dispenser. The cap is automatically rocked forwardly or rearwardly prior to plunger depression for uncovering the orifice without even an awareness by the operator. And, each time the finger force is removed, dispensing terminates during each suction stroke and the orifice is automatically again covered. Moreover, the protector cap in both embodiments forms an essentially smooth extension of the plunger head so as to improve upon the overall appearance. Obviously, many modifications and variations of the present invention are made possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

Claims: A manually operated dispenser for dispensing a product from a container to which the dispenser is attached, the dispenser comprising: a plunger head (10) reciprocable along a central axis thereof, said head having a cylindrical wall (36) containing a discharge orifice (22) through which product is dispensed upon reciprocation of the head (10), and a protector cap (23,39) normally disposed to cover the orifice (22), characterised in that the protector cap (23,39) is pivotally mounted on said plunger head (10) and has an annular wall (28,43) of an outer diameter substantially flush with the outer diameter of the adjacent portions of the cylindrical wall (36), the cap (23,39) in its entirety, including the annular wall (28,43), being pivotally movable relative to the head (10) upon application of finger force to the cap (23,39) in the direction of pump reciprocation for uncovering the orifice (22), means (24,41) being provided for urging the cap (23,39) into its normal position covering the orifice (22) upon removal of the applied finger force. A dispenser according to Claim 1 characterised in that a lower portion (29) of said annular wall (28) covers the orifice (22) in the normal position of the cap (23), said cap having an aperture (31) in the annular wall (28) adjacent the lower portion (29) which is moved into alignment with the orifice (22) upon pivot movement of the cap in response to the said application of finger force. A dispenser according to Claim 1 or Claim 2, characterised in that said means (24,41) is spaced inwardly of said annular wall (28). A dispenser according to any preceding claim, characterised in that said cap (23,39) is provided with an internal projection (35) in contact engagement with said orifice (22) in said normal position of the cap. A dispenser according to any preceding claim characterised in that an upper portion of said cylindrical wall (36) has an annular external means (44) for receiving said annular wall (28,43). A dispenser according to any preceding claim, characterised in that said means (41) comprises a spring for also pivotally mounting said cap (23,39) on said head (10). A dispenser according to claim 6, characterised in that said spring (41) comprises a plate spring.

Inventors: KNICKERBOCKER MICHAEL GENE, KNICKERBOCKER, MICHAEL GENE
Applicants: CALMAR INC, CALMAR, INC.
Application year: 1991
Main classification: B05B11
IPC codes: B05B15, B05B11