Pump with slide valve
Stevens PUMP WITH SLIDE VALVE [4 1 Apr. 15, 1975 3,187,960 6/1965 Gorman 222/321 [7 5] Inventor: Silvester William Stevens,  
 glaCQTane Flelds Primary Examiner-Robert B. Reeves ustra Assistant Examiner-I-ladd Lane [73] Assignee: Precision Valve Corporation, Attorney, Agent, or Firm-Davis, Hoxie, Faithful] &amp;  
 Yonkers, NY. Hapgood [22] Filed: May 28, 1974 [21] App]. No.: 473,802  
 [57] ABSTRACT [30] Foreign Applicatiofl Priority Data A pump for dispensing a product from a retail pack- June 26, 1973 Australia 57358/73 age is molded f plastic A piston having a Central sleeve is free to slide between limit stops on a recipro- [52] US. Cl 222/321; 417/511 cable tubular stem having inlet and Outlet valve ports [51] Int. Cl. GOlf 11/38 f alternate registry with apertures in the Sleeve of [58] Field of Search 222/321, 383, 409, 380; the piston The vent passage and the outlet passage 417/498 4901510, 514, 518 are closed when the pump is at rest.  
 [56] References Cited 7 Claims, 4 Drawing Figures UNITED STATES PATENTS 287,053 10/1883 Powers 417/511 j] 1 .23 l H j 1!], a -63 3 &#39;20 /4 a! t 66 T Z/ 5&#39; i t 26 I8 24 I 27 1 40 I ii l I /2 l /5 PUMP WITH SLIDE VALVE I The present invention is a simple economical pump for use with a product container to dispense a product as a spray, stream or ribbon. Such household products as window cleaners, furniture polish, insecticides, detergents, hand lotions, dental and hair care products, perfumes, foods, medicaments, etc. have long been sold in containers which include a dispensing pump. Boris U.S. Pat. No. 3,627,206, for example, describes a pump of the general type of the present invention.  
  The present invention provides a simple economical pump having few parts which are easily molded of plastic and require minimal assembly procedures. Relatively expensive metal balls which are used as valve elements in many of the prior art pumps are eliminated and the entire pump, except for the return spring, is inexpensively molded of plastic. In the rest position both the air vent and the product discharge passage are closed to prevent unwanted leakage of the product.  
  Accordingly it is an object of the present invention to provide an inexpensive reliable pump suitable for dispensing household products.  
 In the drawings FIG. 1 is a cross sectional view of a pump according to the present invention in the rest position,  
  FIG. 2 shows the pump of FIG. 1 during the initial phase of the actuation stroke,  
  FIG. 3 shows the pump of FIG. 1 at the end of the actuation stroke, and  
  FIG. 4 shows the pump of FIG. 1 during the return stroke.  
  A pump according to the present invention is shown in FIGS. l-4 in the rest position, beginning and end of the actuation stroke and the return stroke respectively. The pump has a housing with a cylindrical interior and has an inlet passage extending through a nipple 12 on the bottom of the housing. An eduction or dip tube 16 can be slipped over the nipple 12 to reach to the bottom of the container. A vent port 17 is provided in the upper portion of the cylindrical wall of the housing. A collar 18 having internal threads 19 provides a means to mount the pump in the mouth aperture of a container such as a bottle having a threaded top. Other attachment means such as a snap bead or the like can be used. A radial flange 14 integrates the collar 18 with the remainder of the housing 10 and overlies and seals against the container lip when the pump is mounted on the container.  
  The reciprocable member of the pump is in two parts, a hollow stem 20 and an associated piston 30. The stem 20 is in the general form ofa tube having inlet and outlet passages 22 and 23 separated by a medial wall or septum 21. The upper portion of the stem including the outlet passage 23 projects upwardly from the pump housing and frictionally retains an actuator button 60 having a passage 62 leading to a discharge orifice 64 in a nozzle insert 65. The lower portion of the stem 20 including the inlet passage 22 is slidingly received in and guided by the inlet passage bore 15 of the housing nipple 12. A compression return spring 40 surrounds the lower portion of the stem and is interposed between a radial flange 24 on the stem and an annular pocket 13 on the bottom of housing 10 to bias the stem 20 upwardly toward the rest position of FIG. 1.  
  The piston 30 is in the general form of an inverted cup having a flared resilient annular margin or skirt 34 for sliding sealed engagement with the cylindrical interior of the pump chamber of the housing 10. .T he piston 30 has a central sleeve 32 through which the upper portion of the stem 20 passes. The fit of the sleeve 32 about the stem 20 permits relative sliding.  
  Inlet passage 22 of stem 20 is in communication with a port 26 extending transversely through the wall of the stem 20. Outlet passage 23 is in communication with a similar port 28. Inlet port 26 intercepts an annular groove 27 circumscribing the stem and outlet port 28 intercepts a similar groove 29. Inlet valve port 26 and outlet valve port 28 are located on stem 20 above radial flange 24 on either side of the medial wall 21 in the region of the stem embraced by the sleeve portion 32 of the piston 30. Sleeve 32 includes a pair of apertures 36 and 38 spaced for alternate registry with grooves 27 and 29 associated with stem valve ports 26 and 28 respectively as the sleeve 32 of the piston 30 reciprocably slides with respect to the&#39;stem 20 during operation of the pump.  
  The central boss 63 of the actuator button 60 is captured within the pump chamber by a radial rib 66 which slides along the interior wall of the housing. The upper end of the housing chamber is provided with an inwardly projecting lip 19 which overlies the rib 66 to act as a stop for upward movement of the button. The rib 66 and lip 19 permit the button 60 to be snapped in place during assembly of the pump. The upstanding upper portion of the stem 20 is frictionally retained in a cavity in the boss 63 of the button 60.  
  Piston member 30 is preferably molded of polypropylene or some other resilient flexible plastic or elastomer. The housing 10, stem 20, and button can be molded of polyethylene, nylon, polypropylene, ABS or other appropriate plastic. The return spring 40.is preferably of stainless steel.  
  The pump above described is to be installed on a container such as a threaded top bottle with the dip tube 16 extending to the bottom of the container for complete product eduction.  
  Beginning from the rest position of FIG. 1, the user depresses the actuator button 60. The initial phase of the actuation stroke is shown in FIG. 2. The stem 20 is fixed to the button and travels downwardly along with the button. The stem slides through the sleeve 32 of the still stationary piston 30 until the lower face of the boss 63 comes to abut the upper face of the piston as can be seen in FIG. 2. The relative position of the piston sleeve 32 and the stem 20 determined by the abutment of boss 63 and the top of the piston places piston sleeve aperture 38 in registry with groove 29 for outlet valve port 28 to open a dispensing passage from the pump chamber through the outlet valve port 28, the outlet passage 23 of the stem and through button passage 62 to the discharge orifice 64. Concurrently with the opening of the outlet valve, the groove 27 for inlet valve port 26 is occluded by the sleeve 32, the sleeve aperture 36 being out of registry with the groove 27 thereby closing off the inlet 15 to the pump chamber.  
  Continued depression of the actuator button drives the stem 20 further downward compressing spring 40. The lower portion of the stem is guided by the inlet passage 15 of the housing as the stem slides through the passage. The end of the downward actuation stroke is illustrated in FIG. 3. Vent port 17 in the cylindrical wall of the housing 10 is now in communication with the atmosphere through the clearance between the boss 63 and the housing interior above the rib 66. The vent passage thus opened allows air to enter the container as product is displaced by the pump.  
  Release of downward force on the actuator permits the return spring 40 to restore the pump to the rest position of FIG. 1. The return stroke is illustrated in FIG. 4. Return spring 40 exerts an upward force on the flange 24 of the stem 20 to drive the stern upwardly. The stem 20 slides upwardly through the sleeve 32 of the piston 30 until flange 24 comes to abut the sleeve thereby causing the piston to move upwardly with the stem. When so engaged by the stem flange 24 piston sleeve 32 is positioned on the stem with the groove 27 for the inlet valve port 26 in registry with sleeve aperture 36 to open the inlet valve to communicate the pump chamber with the container through the inlet port 26, stem inlet passage 22, housing inlet passage and dip tube 16. Concurrently, the groove 29 for the outlet valve port 28 is occluded by the sleeve 32, the sleeve aperture 38 being out of registry with outlet port 28. Retreat of the piston reduces the pressure in the pump chamber below atmospheric to draw product from the container into the chamber. The pump comes to rest in the condition of FIG. 1 with the chamber filled and ready for the next actuation stroke. The face of the boss 63 and the flange 24 serve as motion limiting stops for the movements of the piston 30 with respect to the reciprocable stem 20. In the rest position the outlet valve port 28 is closed by sleeve 32 to prevent leakage of product from the discharge orifice 64. The vent passage is blocked when the pump is in the rest position of FIG. 1 by the interposition of rib 66 between port 17 and the exterior to prevent product leakage. Rib 66 on button boss 23 seals against the lip 19 of the housing to further close off the vent path to prevent leakage.  
  The just decribed pump is intended to be included in the retail package for some household product. Because the inlet and outlet valves as well as the vent passage are closed when the pump is at rest position the pump can be placed on the container by the product packager without fear of leakage of product during shipment and storage. An overcap can be installed over the pump actuator button to prevent accidental actuation and to discourage trials by shoppers. To be acceptable to the packager, such a pump must be sufficiently inexpensive to be includable in the retail price of the product while remaining competitive with others products, must be a pump adequate to the purpose to please the customers, and must not leak in shipment and storage. The present pump fulfills these requirements.  
 What is claimed is:  
  l. A dispensing pump construction for mounting on a container comprising:  
 a housing having side and bottom walls defining a cylindrical interior chamber and having a bore extending through the bottom wall of the housing, said bore being in communication with the interior of the container,  
 means to mount the pump in the mouth aperture of a container,  
 a reciprocable hollow tubular stem member movable from a rest position through actuation and return strokes, said reciprocable stem member including an axial bore blocked by a medial wall to divide the bore into an upper outlet passage and a lower inlet passage, an outlet valve port extending through said stem above said medial wall and in communication with said&#39;outlet passage, and an inlet valve port extending through said stem below said medial wall and in communication with said inlet passage; a lower portion of said stem being slidingly received in the bore through the bottom of the housing, and an upper portion of the stem extending outwardly of said housing,  
 a pump piston member slidingly received in said housing chamber, said piston having a central tubular sleeve portion through which said stem slides, said sleeve including inlet and outlet valve apertures located with respect to said stem inlet and outlet ports for alternate communication with said ports as said sleeve slides with respect to said stem,  
 stop means on said stem to limit relative motion of the piston sleeve and stem to effect alternative opening of the inlet and outlet valve ports, and  
 a return spring for biasing the stem toward the rest position.  
  2. The pump of claim 1 wherein said stop means comprise an annular flange about said stem below said piston sleeve and a lower portion of an actuator frictionally mounted on the upper portion of said stem.  
  3. The pump&#39;of claim 2 wherein said lower portion of the actuator is the lower face of a cylindrical boss surrounding a stem receiving socket.  
  4. The pump of claim 3 wherein the housing includes a vent port through the side wall and the lower portion of said cylindrical boss includes an annular rib for sealingly engaging the interior of the housing side wall, said vent port being above said rib when the pump is actuated to establish a vent path from the container to the atmosphere.  
  5. The pump of claim 4 wherein the housing includes an inwardly projecting annular lip which overlies the rib of the boss.  
  6. The pump of claim 1 wherein the means to mount the pump comprise a threaded collar.  
  7. The pump of claim 1 wherein the stem inlet and outlet ports intercept annular grooves circumscribing the stem and said ports alternately communicate with said sleeve valve apertures through said grooves.