Patent Publication Number: US-3880605-A

Title: Manufacture gas propelled dispensers

Description:
United States Patent [191 Webster [4 1 Apr. 29,1975  
 [ MANUFACTURE GAS PROPELLED DISPENSERS [75] Inventor: Milo E. Webster, Braintree, Mass.  
 [73] Assignee: The Gillette Company, Boston,  
 Mass.  
 [22] Filed: July 16, 1973 [21] Appl. No.: 379,632  
 [52] US. Cl. 29/407; 29/445; 72/30 [51] Int. Cl B23q 15/02 [58] Field of Search 29/407, 434, 445; 222/402.l; 72/30, 6  
 [56] References Cited UNITED STATES PATENTS 3,396,449 8/1968 Brantner 29/407 Primary Examiner-C. W. Lanham Assistant E.\&#39;aminer--Dan C. Crane [57] ABSTRACT Method for manufacturing a gas propelled dispenser having a valve with a stem accurately placed at a desired position with respect to the cannister thereof by assembling a dispenser with a cannister having a reference structure affixed thereto, and a valve with a reference structure affixed thereto and with a seat structure joined to said cannister by a plastically deformable structure requiring for deformation application of a force larger than that required for opening the valve, the dispenser being initially assembled with said valve stem displaced from its desired position; then without opening said valve, moving a gage element into engagement with one of the reference structures, the gage element including a sensor connected to signal when the other of the reference structures assemes a defined position corresponding to the desired displacement between the valve stem and the cannister; then applying sufficient force to the valve seat structure while maintaining the gage element in engagement with one reference structure to plastically deform the deformable structure without opening the valve; and then generating a signal when the other of the reference structures assumes the defined position and applying the signal to terminate the application of force to the valve seat structure.  
 6 Claims, 10 Drawing Figures I26 llO MANUFACTURE GAS PROPELLED DISPENSERS BACKGROUND OF THE INVENTION This invention relates to manufacturing gas propelled dispensers.  
  The manufacture of gas propelled dispensers is commonly carried out using extruded parts and manufacturing techniques such as rolling and crimping which are not well adapted to maintain close dimensional tolerances. Ordinarily the loose tolerances are not objectionable, but when it is desired to manufacture a dispenser providing two different modes of discharge-for example, at a high rate and a low rate-closer tolerances are advantageous in order to accurately establish the position of valve parts and define the operation of the valve in its several modes of discharge.  
 SUMMARY OF THE INVENTION A principal object of the present invention is to manufacture gas propelled dispensers having valves with stems accurately placed at a desired position with respect to the canister thereof. A further object is to manufacture such dispensers inexpensively and with automatic equipment at high manufacturing rates.  
  The invention features a method for manufacturing a gas propelled dispenser having a valve with a stem accurately placed at a desired position with respect to the canister thereof by assembling a dispenser with a cannister having a reference structure affixed thereto, and a valve with a reference structure affixed thereto and with a seat structure joined to said cannister by a plastically deformable structure requiring for deformation application of a force larger than that required for opening the valve, the dispenser being initially assembled with said valve stem displaced from its desired position; then without opening said valve, moving a gage element into engagement with one of the reference structures, the gage element including a sensor connected to signal when the other of the reference structures assumes a defined position corresponding to the desired displacement between the valve stem and the cannister; then applying sufficient force to the valve seat structure while maintaining the gage element in engagement with one reference structure to plastically deform the deformable structure without opening the valve; and then generating a signal when the other of said reference structures assumes the defined position and applying the Signal to terminate the application of force to the valve seat structure.  
  Emobidments of the invention feature positioning mechanism for holding a dispenser in a predetermined position; a ram supported for movement toward and away from a dispenser so held, the ram shaped for engaging the valve of the dispenser without touching the valve stem thereof; means for moving the ram with sufficient force to deform the deformable structure of the dispenser; a gage element mounted in position to engage the dispenser reference structure as the ram moves toward the dispenser; an indicator including an electrical circuit element resiliently urged against the valve stem of a dispenser and closing a contact to emit a signal when the valve stem assumes a position relative to the gage element corresponding to the predetermined projection; and a controller connected to the ram to control the motion thereof and connected to the indicator to receive signal therefrom, said controller initiating motion of said ram toward a dispenser when so positioned and being responsive to said signal to terminate said motion.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the upper portion of a dispenser with two dispensing rates, in part cut away to reveal interior parts. manufactured according to the invention;  
  FIG. 2 shows a cross-sectional view of the dispenser of FIG. I with the valve stem in a nondispensing condition;  
  FIG. 3 shows a similar cross-section with the valve positioned to dispense at the lower of the two rates;  
  FIG. 4 shows another similar cross-section with the valve positioned to dispense at the higher rate;  
  FIG. 5 is a block diagram indicating a sequence of steps of processing a dispenser according to the invention;  
  FIG. 6 shows apparatus to manufacture according to the invention the dispensers as shown in FIG. 1;  
  FIG. 7 shows in more detail a portion of a valve height equalizer shown in FIG. 6; and  
  FIGS. 8, 9, and 10 show in cross-sectional view successive stages of the manufacturing method employed in the apparatus of FIG. 5.  
 DESCRIPTION OF THE PREFERRED EMBODIMENT As shown particularly in FIG. 1, dispenser 10 includes cannister 12 with cannister top 14 crimped to cylindrical portion 16. The valve 18 is joined to the top of cannister 12 by plastically deformable structure 20 sealed at roll crimp22 to the edge of cannister top 14. Cannister 12 together with the valve 18 and structure 20 define a closed chamber holding the product to be dispensed and a dispensing propellant. Tube 23 connected to the inlet of valve 18 extends to the bottom of canister 12 and delivers product from the bottom of the canister chamber to the valve inlet. Valve stem 24 with reference surface 25 at its top protrudes upward from the main part of valve 18 and containsan axial passage 26 for delivery of product to dispensing head 28. It may be noted that dispensing head 28 has been shown in FIG. 1 as raised from its normal position on the valve stem 24 to permit a clearer view. Reference structure 30, advantageously made of an organic polymer, is supported on roll crimp 22 and secured in place by a press fit. Reference structure 30 has a raised lip 32 with a pair of opposed shallow notches 34 and a pair of opposed deep notches 36.  
  The construction of valve 18 is shown more particularly in FIG. 2. Structure 20 is secured to valve housing 38 at crimp40. Structure 20 continues to form valve seat structure 42 over the top of valve housing 38. Elastomer seal 44 is captured and secured in place between housing 38 and valve seat structure 42. Valve stem 24 protrudes&#39;upwards through acentral hole in valve seat structure 42. Spring 46 pushes valve stem 24 upwards so that sealing lip 48 is pressed into elastomer seal 44. Lateral passage 50 provides communication between axial passage 26 and the outer surface of valve stem 24 near the bottom of passage 26. Lateral passage 52 provides a similar communication a small distance farther up the valve stem. As shown in FIG. 2, dispensing head 28 is fitted around valve stem 24 and seats against the flat reference surface 25 at the top of valve stem 24. Dispensing head wings protrude from dispensing head 28 with their bottom portions entering into notches 34 or 36. Dispensing head 28 may be twisted counterclockwise (looking down on the cannister) to place wings 60 opposite shallow notch 34 or alternatively may be twisted clockwise to place wings 60 opposite deep notch 36. When the valve is in its nondispensing position, as illustrated specifically in FIG. 2, the bottom of wings 60 are positioned higher than shallow notch 34 and a seal is maintained between sealing lip 48 of the valve stem and elastomer seal 44. The configuration the parts assume for low dispensing rate is shown in FIG. 3. Dispensing head 28 has been rotated so that wings 60 are opposed to shallow notch 34 and the dispensing head has been depressed (as by the finger of the user) until the bottom of wings 60 press against shallow notch 34. Valve stem 24 has accordingly been pressed down to open the seal between sealing lips 48 and elastomer seal 44 and lateral passage 50 has been moved below the lower surface of elastomer seal 44. Product accordingly flows up through tube 23 into valve housing 38 and thence between lip 48 and elastomer seal 44 through lateral passage 50 to axial passage 26 and is thereupon dispensed through dispensing head 28. In this position, lateral passage 52 is, as shown in FIG. 3, blocked by elastomer seal 44 and is not effective as a passage for the product to flow through to axial passage 26. The flow of the product is controlled primarily by the size of lateral passage 50. The position of the elements for high dispensing rate is shown in FIG. 4. Here dispensing head 28 has been rotated to place wings 60 opposite deep notch 36 and the dispensing head has been depressed until the bottom of wings60 press against deep notch36, with the result the valve stem is pushed in farther than it was in FIG.  
 3. As a result, the second lateral passage 52 has been pushed below the elastomer seal 44 to provide an additional operative channel for the flow of product into axial passage 26, resulting in a faster delivery of product.  
 &#39; It can be readilyappreciated from the foregoing description that the position of the valve stem with relation to notches 34 and 36 must be established with con- &#34;siderable accuracy to assure that in the position for low dispensing rate, lateral passage 50 is exposed below elastomer seal 44 but lateral passage 52 continues to be blocked by elastomer 44 and that in the higher dispensing rate position lateral passages 50 and 52 are both exposed.  
  Apparatus for constructing dispenser according to the invention is shown diagrammatically in FIG. 5. Major parts of the dispenser are formed and assembled at assembly station 70. The cannister is transferred from station 70 to filling station 72 where product is charged into the cannister. Filled cannisters are transferred from station 72 to valve installation station 74 where valve 18 is affixed to cannister 12, the valve being affixed so that valve stem 24 is above the position it must occupy in the completed dispenser. From station 74 the dispenser is transferred to charging station 76 where propellant is charged into the dispenser.  
 From&#39; station 76, the cannister passes to stations 78 where reference structure 30 is installed and is then conveyed to station 80 where the valve stem adjustment is accomplished, as will be more particularly described below, and then to station 82 where dispensing head 28 is installed.  
  Valve adjusting station 80 is shown particularly in FIG. 6&#39;. Dispenser l0 filled with product and charged with propellant are conveyed to stations on conveyer belt 82 and are successively positioned by rotating jig 84 on base 86 underneath valve adjusting ram 88. Ram head assembly 90 is connected by signal lead 92 to controller 94 which, in response to signals received on lead 92, controls the operation of ram 88. Dispensers with adjusted valves are conveyed from valve adjusting station 80 on conveyer 96. As shown more particularly in FIGS. 7 and&#39;8, ram head assembly 90 includes ram 102 of a diameter permitting it to slip through reference structure 30 and engage valve seat structure 42. Ram 102 has a central axial cavity 105 permitting valve stem 24 to enter without touching ram 102. Ram 102 also has a transverse slot 104 cut through it and a spring retaining flange 106 affixed to the main body of the ram at a level above slot 104. Gage element 108 is fitted to ram 102 and includes contacting plate 110 slidably mounted on ram 102 with contacting face 111 and sensor bar 112 with engaging face 113. Spring 114 bears against flange 106 and urges contacting plate 110 downwards. When the ram head assembly is in its disengaged position as shown in FIGS. 7 and 8, contacting plate 110 is pressed against ring 116. Sensor bar 112 fits through transverse slot 104 with guide bar 118 fitting slidably into cavity 120 of ram 102. Spring 122 is captured in cavity 120 thrusting downward on guide bar 118 so that sensor bar 112 seats on the bottom of slot 104. It should be particularly noted that spring 122 is designed to have a spring force less than that of spring 46 in the valve. Sensor-bar 112 is made of electrically conductive material and has contact points 124 at each end. Contacts 126 are affixed to but insulated from contacting plate 110 and connected through leads 92 to controller 94.  
  The adjustment of the valve stem position is illustrated particularly in FIGS. 8, 9 and 10, showing sequential steps of the operation. When a dispenser 10 has been properly placed beneath ram 88 by jig 84, controller 94 initiates the advance of ram 88. The ram descends on the dispenser until contacting portion 111 of contacting plate 110 engages reference structure 30 and is lifted off retaining ring 116, face&#39;l13 of sensor bar 112 engages valve stem reference structure 25 and is lifted off the bottom of slot 104, and the face of ram 102 engages valve seat structure 42. The order in which the three mentioned engagements occur is immaterial. The position of the various parts after the three engagements mentioned havetaken place is shown in FIG. 9. Following the engagement of elements as described, the ram continues to descend pushing valve seat structure 42 downwards and bending plastic ally deformable structure 20. During this part of the operation, spring 114 maintains contacting portion 111 of contacting plate 110 engaged with reference structure 30 while ac-&#39; commodating to the relativemotion between ram 102 and plate 110. Similarly spring 122 maintains face 113 of sensor bar 112 engaged with valve stem reference structure 25. Because the spring force of spring 122 is less than that of spring 46 in the valve, the valve is not opened. As the ram descends, lowering the .valve with its stem, sensor bar 112, which is during this part of the operation supported on the valve stem, moves downward with the ram, while contacting plate 110 which is supported on reference structure 30, does not move. The result is that the gaps between contact points 124 and contacts 126 diminish until electrical contact is made between each of the points 124 and the opposed contact 126 as is shown in FIG. 10. The contacting of the points with the contacts closes an electrical circuit through leads 92, sending a signal to controller 94 which thereupon terminates the advance of the ram. The gage elements are made with dimensions such that when the contacts are made. the vertical distance between face portion 111 and the part of sensor bar 112 touching valve stem reference structure 25 is just equal to the vertical distance required between reference structure 30 and valve stem reference structure 25 for proper operation of the valve. The valve stem of each dispenser will therefore be correctly positioned after the adjusting operation as described, even though there may be considerable variation in the length of valve stems or in the position of valves and other parts as initially assembled.  
  Other embodiments of the invention within the scope of the claims will readily be seen by those skilled in the appropriate art. Optical or pneumatic devices might, for example, be used to define and sense the position of the gage reference structures, or the cannister might be supported by a clamp around crimp 22 during the adjusting operation.  
  I claim: 1. A method for manufacturing a gas propelled dispenser having a valve with a stem accurately placed at a desired position with respect to the cannister thereof comprising the steps assembling a dispenser with a cannister having a reference structure, and a valve with a reference structure and with a seat structure joined to said cannister by a plastically deformable structure requiring for deformation application of a force larger than that required for opening said valve, said dispenser being initially assembled with said valve stem displaced from said desired position,  
 without opening said valve, moving a gage into engagement with one of said reference structures, said gage including a contacting portion for engaging with said one of said reference structures and a sensor connected to signal when the other of said reference structures assumes a position defined relative to said contacting portion, the displacement between said contacting portion and said defined position being equal to that between said reference structures when said stem is in said desired position with respect to said cannister,  
 applying sufficient force to said valve seat structure while maintaining said gage in engagement with said one reference structure to plastically deform said deformable structure without opening said valve, and  
 generating a signal when said other of said reference structures assumes said defined position and applying said signal to terminate the application of force to said valve seat structure.  
  2. The method as claimed in claim 1, said valve reference structure being affixed to said valve stem.  
  3. The method as claimed in claim 2, said contacting portion engaging with said cannister reference structure.  
  4. The method as claimed in claim 3, said sensor including an engaging structure, and said method including the steps engaging said sensor engaging structure with said valve stem reference structure and generating said signal when said sensor engaging structure assumes a position relative to said contacting portion corresponding to the desired position of said valve stem relative to said cannister reference structure.  
  5. The method as claimed in claim 1 including the step of filling said dispenser with product before moving said gage element into engagement.  
  6. A method for establishing a predetermined projection of a valve stem of an aerosol dispenser valve relative to a reference structure of the dispenser, said valve beingjoined to the cannister of said dispenser by a plastically deformable structure requiring for deformation application of a force larger than that required for opening said valve, said dispenser having been initially assembled with said valve stem positioned with a projection in excess of said predetermined projection, comprising the steps of positioning a dispenser in ajig in predetermined position relative to a ram supported for movement toward and away from said dispenser held in said jig and a gage mounted in position to engage said dispenser reference structure as said ram moves toward a dispenser so held, said ram being shaped for engaging the valve of a dispenser so held, without touching the valve stem thereof,  
 moving said ram with sufficient force to deform said deformable structure of the dispenser so held,  
 sensing when a valve stem of a dispenser assumes a position relative to said gage corresponding to said predetermiend projection, emitting a signal thereupon,  
 and terminating motion of said ram toward the dispenser in response to said signal.