Self-sealing viscous material dispenser loading apparatus

Abstract

A dispenser for air-curable viscous material is provided with a cartridge-type loading apparatus that is characterized by incorporating means for sealing the dispenser feed conduits to viscous material supply receptacles by forming an air tight gasket with a portion of the material discharged from each of the successive receptacles loaded into the apparatus. A release surface is provided in the loading apparatus to assure that the successive sealing gaskets thus formed will be removed from the apparatus with the respective receptacles for which they afford a sealing function.

Description

BACKGROUND OF THE INVENTION

The invention relates to dispensers for air-curable viscous material and, more particularly, to means for sequentially sealing a plurality of cartridge-type viscous material supply receptacles to a loading apparatus for such a dispenser.

It is known in the prior art to supply air-curable viscous material to a dispensing apparatus in the form of cartridge-type receptacles. A major problem encountered in using such loading arrangements is that an air-tight seal must be formed between each of the successive receptacles and the conduit means coupled with the receptacles to feed material from them into the dispenser. In general, two solutions to this universal problem have been developed in the prior art. The first of these is to provide an intermediate storage chamber within the dispensing apparatus, so that the cartridge-type receptacles can be emptied into this intermediate container from which the material is fed directly into a conduit that supplies a high pressure pump for the dispenser. An inherent difficulty with this type of system is that the intermediate chamber must be kept substantially air tight so that material in it does not cure or partially cure. The second conventional type of system now more generally utilized with cartridge-type loading receptacles is to provide a removable sealing gasket around an aperture in the receptacle and its juncture with a supply conduit to the dispenser. Two significant operating difficulties are encountered with this type of loading system. It is often hard to initiate a loading cycle without spilling some of the material around the gasket area, so that the area becomes contaminated and then frequently has to be cleaned to prevent air from leaking past the gasket into the basic supply channel where it would cure the dispensed material. In addition, the removable gasket must usually be replaced with each new charge, because the air-curable materials stick to them and essentially destroy them for further effective use. Finally, with such removable sealing gasket arrangements, even when they are kept clean, it is typical to have some leakage of viscous material around the gasket, which causes the dispensing receptacles to be substantially bonded to the supporting frame on which they are positioned during their discharge cycle. Accordingly, the efficient operation of the loading apparatus must frequently be interrupted to disengage such a bonded loading receptacle and appropriately clean the supporting surface before a new receptacle and gasket are placed in position.

It is a primary object of the present invention to provide a self-sealing, viscous material dispenser loading apparatus that overcomes the above-noted problems and difficulties of prior art loading apparatus for related dispenser systems.

Another object of the invention is to provide a cartridge type receptacle loading apparatus for a dispenser system that is adapted to dispense air-curable viscous material.

A further object of the invention is to provide a dispenser loading apparatus that is operable to be self-sealing to the inlet, or low-pressure side, of a high pressure dispensing system so that the loading apparatus can be supplied by cartridge-type receptacles that need not be sealed to the high pressure dispenser with separate, re-usable gaskets.

Still another object of the invention is to provide a dispenser loading apparatus with means for sequentially mounting cartridge-type supply receptacles in sealed relationship therewith, while preventing any of the receptacles from being permanently bonded to the loading apparatus by the air-curable material dispensed therefrom.

Those skilled in the art will recognize that additional objects and advantages of the invention may be afforded by it, based upon the following disclosure.

SUMMARY OF THE INVENTION

In one preferred embodiment of the invention a self-sealing, viscous material dispenser loading apparatus is provided with means for sequentially receiving a plurality of cartridge-type supply receptacles that are uniquely coupled in sealing relationship to supply viscous material to a conduit that feeds a high-pressure dispenser. The loading apparatus is characterized by including means for forming a sealing gasket of the dispensed material so that air is not allowed to contamainate the flow of material from the supply receptacles to the dispensing system. Furthermore, the supply receptacles are prevented from either contaminating the loading apparatus or from being permanently bonded to it by dispensed material that may be spilled from the supply receptacles. These desirable functions are accomplished by affording a unique gasketforming channelway between the successive supply receptacles and a non-stick plate member in the loading apparatus. As successive supply receptacles are positioned in the loading apparatus, sealing gaskets are formed between one surface of them and a surface of the non-stick plate member, then a discharge hole is punctured in the receptacle so that material can flow through it to the high-pressure dispensing system. After each supply receptacle is emptied, it is removed from the non-stick plate causing the sealing gasket, which is usually automatically cured and bonded to the receptacle, to also be removed from the loading apparatus so that it is thus pre-conditioned to receive the next supply receptacle.

Description of the Drawings

FIG. 1 is a side elevation view, partly in cross-section, illustrating a dispenser loading apparatus constructed in accordance with the teaching of the present invention, and coupled in operative relationship to a high-pressure dispenser system for air-curable viscous material.

FIG. 2 is an exploded perspective view of a portion of the dispenser loading apparatus shown in FIG. 1, illustrating the means utilized in the preferred embodiment of the invention to form a self-sealing gasket between a supply receptacle and the loading apparatus.

FIG. 3 is a perspective view of an alternative embodiment of a non-stick plate member shown in FIG. 2 of the drawings.

Description of the Preferred Embodiment

Referring first to FIG. 1 of the drawings, it will be seen that there is shown a dispenser loading apparatus 1 that is adapted to receive a cartridge-type supply receptacle 2, such as the illustrated metal can, for feeding viscous material to a conventional highpressure dispensing system 3. The present invention need not necessarily involve any particular form of structure for the high-pressure dispensing system 3, therefore, this high-pressure system will only be described in general terms to help orient the invention. The dispenser 3 comprises a high-pressure air pump 4 operatively coupled to a pressure cylinder 5 from which viscous material is forced under high pressure through a conduit 6 to a dispensing nozzle 7 through which flow is regulated by a manually operable valve 8. A gas charged pressure accumulator 9 is mounted in communication with the conduit 6 by a conventional T-connection 10 to provide a means for stabilizing the width of a stream of viscous material discharged from the nozzle 7. As is well known, the pressure accumulator 9 serves to absorb surges of pressure induced in the conduit 6 by the operation of air pump 4, thereby to prevent such surges from being transmitted to the dispensing nozzle 7.

The high pressure dispenser 3 is fed viscous material through a supply conduit 11 that is coupled in a conventional, air-tight manner, to the cylinder 5. Of course, any suitable means may be used to support the dispenser 3 in operating position. In this embodiment of the invention, dispenser 3 is rigidly mounted on a steel frame 12 and secured thereto by a plurality of bolts 13 and 13'.

The loading apparatus 1 can either comprise a separate frame or, as in this embodiment of the invention, the steel frame 12 supported on legs 14 and 14' may be used so that the loading apparatus 1 and the high-pressure dispenser 3 constitute a single assembly. Pursuant to the invention, the conduit 11 is connected in sealing relationship to the frame 12 in any suitable manner. In the present case, to effect this connection the conduit 11 is threaded into a tee-connector 15 and a sleeve 16 is threaded into the upper end of the tee and into a threaded aperture 17 formed through the flat plate portion of frame 12. A second sleeve 18 is threaded into the bottom end of the tee 15 to operatively couple a hydraulic or pneumatic cylinder 19 and a reciprocally mounted, hydraulically or pneumatically actuated spike 20 to the tee in air-tight relationship, for a purpose that will be described more fully below.

A plate member 21 is mounted on the upper surface of frame 12 and rigidly secured to it by a plurality of bolts 22 and 22' that extend through apertures in the plate member into threaded wells in the frame 12. As the description of the invention proceeds, it will become apparent that although the plate member is rigidly secured to the frame 12 in the preferred embodiment of the invention, it will be possible to afford the desirable objectives of the invention by providing other, less rigid means for mounting the plate member 21 in relation to the frame 12. For example, a suitable flexible coupling means, such as a short cable or cables, might be used between these two components of the loading apparatus 1 to cause plate member 21 to be generally positioned in relationship to the discharge passageway 17 while, at the same time, holding it within a limited range of movement with respect to the frame 12.

An aperture 23 is formed by any suitable means through a generally central portion of the plate member 21 and the aperture 23 is positioned in communication with the inlet end of the discharge passageway 17 formed through frame 12. As will be seen hereinafter, such a configuration is not necessary but it facilitates the removal of the sealing gaskets, that will be described, from the loading apparatus. The plate member 21 is formed to have a first surface 21a that is substantially complementary to the receptacle-supporting surface of frame 12 on which the plate member is mounted. Plate member 21 also has a second surface 21b that is formed to coact with a bottom surface 2a of receptacle 2 that is movably positioned on the frame 12 to thereby form a channel 24 between the surface 2a and the surface 21b on the plate member 21. As will be understood from the following description, the channel 24 constitutes a characteristic feature of the present invention.

In order to form channel 24 so it will operate effectively in accordance with the present invention, one of the coacting surfaces 2a or 21b is provided with a plurality of spaced-apart bosses, such as the bosses 25a-25d on receptacle surface 2a, best seen in FIG. 2. These bosses operate to engage the other coating surface, in this case surface 21b on plate member 21, thereby to effectively determine the height of channel 24 adjacent to the bosses. I have found that only a limited range of various heights of bosses 25a-25d are acceptable for forming the self-sealing gasket means afforded by the invention. Specifically, these bosses should be no greater than one-fourth inch in height so that they restrict flow of viscous material in the channel 24 sufficiently to cause it to be cured by exposure to air within a pre-determined portion of the area of the surface 2a on the bottom of receptacle 2. In the preferred embodiment of the invention, the bosses 25a-25d are less than one-eighth inch in height and preferably approximately one thirty-second inch in height. It should also be understood that the bosses 25a-25d may vary in number and may have different configurations and relative locations with respect to the discharge aperture 23 in plate member 21. However, to maintain the channel 24 at a desired pre-determined height for a suitable distance to enable viscous material to be forced easily into it when the spike 20 is driven upward, in the manner that will be described hereinafter, it has been found that the bosses 25a-25d should preferably be located within the area defined by a circle having a radius of 4 inches from the center of aperture 23.

As shown in FIG. 2, in this embodiment of the invention, the plate member 21 is generally disc shaped and is secured to the frame 12 by the bolts 22, 22', etc., that are positioned at spaced-apart points adjacent the periphery thereof. Thus, by removing the securing bolts, the plate member 21 can be taken from the frame 12, if necessary. Again, it should be understood that in various embodiments of the invention, the plate member 21 may be permanently fastened to the frame 12 by being fused or otherwise bonded to it, rather than being releasably secured in its fixed position, as shown herein. Finally, in this embodiment, the upper surface 21b of plate member 21 is generally flat, but it should be understood that in other embodiments illustrated in FIG. 3, the upper surface 21b of plate member 21 can be provided with a pair of integral bosses 21c and 21d. Again, these bosses can take various configurations and may be located in various positions with respect to the aperture 23 formed in the plate member, but they must be within the range of heights given above, i.e., one thirty-second inch to one-fourth inch, in order for the invention to perform in an optimum manner.

An important feature of the present invention is the use of a relatively non-stick surface to form the plate member 21. At least the upper surface 21b of plate member 21 should be formed of such non-stick material to afford the desirable objectives of the invention. In the preferred embodiment described herein, the plate member 21 comprises a one-fourth inch thick disc of a non-stick material that is taken from the group consisting essentially of fluorinated polymers with at least two fluorine atoms per repeating unit of their monomer, (such as tetrafluoroethylene polytetrafluoroethylene, etc.), polyethylene, polypropylene, polyoxymethylene, and non-plasticized polyvinyl chloride resins. These materials have been found to be particularly well suited for dispensing air-curable viscous material such as room-temperature-vulcanized (RTV) silicone rubber that readily sticks to many other more typical gasket materials, such as hard rubber. Moreover, even potential alternative resin gasket materials, such as those formed of nylon, have been found to be unsuitable to form the "non-stick" plate member 21 of the invention. By forming the second surface 21b of plate 21 of one of the foregoing materials from the preferred group, all of which are commercially available under various tradenames such as "Teflon" (tetrafluoroethylene) or "Delrin" (polyoxymethylene), the second surface 21b is rendered effective to prevent the receptacle 2 mounted on it from being firmly bonded to either it or the frame 12 when a self-sealing gasket is formed pursuant to the invention in the manner that will now be described.

As pointed out above, a reciprocally operable spike 20 is mounted in air-tight relationship to the discharge passageway 17 and is hydraulically or pneumatically actuated by the piston 19 that may be supplied in any conventional manner from a selectively controllable source of hydraulic or air pressure (not shown). After a supply receptacle, such as the receptacle 2, is mounted on the frame 12, the cylinder 19 is actuated to drive the spike 20 upward through the passageway 17 thereby causing it to force any viscous material stored in the passageway or in the inlet end of conduit 11 and tee 15 upward and outward through the channel 24. As the material moves outward in channel 24, it forms a sealing gasket around the passageway 17 before the spike 20 (as shown in phantom by outline 20') is driven through the surface 2b of receptacle 2 to puncture a hole in it. After such a hole is punctured, the spike 20 is retracted into the cylinder 19 so that viscous material can flow through the aperture 2c and into conduit 11.

It should be understood that the bottom (2a) of receptacle 2 is made of sufficiently flexible or resilient material so that the surface 2b is forced into contact with the upper surface 21b of plate member 21 adjacent the aperture 23 when the discharge passageway is not filled with viscous material. Normally, that circumstance will occur only when the initial receptacle 2 of a series is loaded into the apparatus 1, following a shut-down period during which the passageway 17 is cleaned. In such a case, very little viscous material will be forced into the channel 24 from the first receptacle, but any material that does enter the channel is cured in place to form a sealing gasket. As is explained more fully below, subsequent receptacles 2 have larger sealing gaskets formed in the channel 24 by the upward movement of spike 20.

In order to force viscous material from the cartridge-type receptacle 2, a vertically movable plunger 26 mounted on a piston rod 27 is mounted in operative relationship, as shown, over the receptacle 2 A suitable steel frame 28 supported on posts 28a and 28b has mounted on it a hydraulic cylinder 29 which houses the upper end of piston rod 27 and a driving piston (not shown) connected to it. Again, any conventional means (not shown in detail) may be used to selectively energize the hydraulic or air cylinder 29 to move the piston rod 27 downward, as is well known.

In this form of the invention, the viscous material provided in a series of sequential receptacles such as the receptacle 2, is a commercially available RTV silicone rubber 30 that is housed in a sealed plastic bag 31, separate from receptacle 2. This arrangement serves to prevent the rubber 30 from coming in contact with the plunger 26 as it is moved downwardly within the receptacle 2 to force the rubber 30 to be discharged through the hole 2c punctured in the bottom surface 2a thereof.

The operation of the invention may be generally understood from the foregoing description of it, however, in order to further clarify the invention, a brief description of the operation will be given now. When the dispenser 3 and its loading apparatus 1 are initially placed in operation, there will be no viscous material, such as the silicone rubber 30, in the conduit 11 or downstream thereof to the nozzle 7. To load a charge of viscous material into the dispenser, the plunger 26 is raised to the upper position shown in FIG. 1 and a cartridge-type receptacle 2 filled with a separately housed charge of viscous material 30, is mounted on the plate member 21 so that a downwardly projecting annular lip 2e of the receptacle overhangs the outer circumference of the plate member 21. (The lip 2e may contact the steel frame 12 but need not do so.) In the preferred embodiment of the invention, the lip 2e is at least twice as high as the bosses 25a-25d and cooperate with the bosses 25a-25d on the bottom surface 2b of receptacle 2 to form the channel 24, which, as noted above, is one thirty-second to one-fourth inch in height adjacent the bosses. In addition, the size of plate member 21 is preferably determined so that the lip 2e fits snugly around its circumference, to limit the dishcarge of air from channel 24 and thus retard flow of viscous material 30 therein. The plunger 26 may then be driven downward to lightly contact the upper surface of flexible bag 31 and exert a pressure on the rubber 30 that forces any air that may be trapped between the bag 31 and the bottom or sides of receptacle 2 out of the receptacle. Spike 20 is then driven upward out of cylinder 19 to puncture the hole 2c in the bottom of receptacle 2.

Since there may be no viscous material in the discharge passageway 17 during its initial start-up condition, the channel 24 could be filled with air until the spike 20 is retracted into the cylinder 19. At that point, the viscous material 30 flows through the passageway 17 into conduit 11 and at the same time, part of the material flows outwardly around the discharge passageway 17 into the channel 24. Since the viscous material is air curable and the height of the passageway is restricted to less than one-fourth of an inch (preferably to approximately one thirty-second of an inch, as noted above), the viscous material forms a pattern such as that shown in the area of the bosses 25a-25d in FIG. 2 by the line numbered 32, (or by the dotted line 32' shown in the embodiment of FIG. 3). The viscous material is thus cured and trapped in the channel 24 in a pre-determined region around the discharge aperture 17 and serves to define a sealing gasket around the main flow of viscous material from the receptacle 2 into the conduit 11, so that it is not contaminated by exposure to air.

High pressure pump 4 is operated to charge the discharge conduit 6 to the valve 8. Thus, when the valve is opened, viscous material may be selectively discharged from the nozzle 7 as desired. Although not shown in FIG. 1, it will be understood that suitable control means and a source of actuating hydraulic pressure will be supplied to the high pressure pump 4 to selectively control the flow of viscous material through the conduit 6 to nozzle 7. After the receptacle 2 has been emptied following the movement of plunger 26 to the bottom surface thereof, plunger 26 is raised and the receptacle 2 is lifted from the frame 12, as shown in FIG. 2. Because the sealing gasket formed by the curable viscous material is bonded to the bottom surface 2a of receptacle 2, it is automatically lifted off of the non-stick upper surface 21b of plate member 21, as shown in FIG. 2. Thus, the top surface 21b is completely cleaned and is immediately ready to receive the next receptacle (similar in shape and content to receptacle 2 so that the foregoing loading cycle to the dispenser 3 can be repeated.

In successive repetitions of the loading cycle, it will be noted that after a fresh receptacle 2 is mounted on the frame 12 and on the upper surface of plate member 21, when the spike is driven upward from the cylinder 19 towards the receptacle 2, it will force viscous material caught in the discharge passageway 17 outward into the channel 24 to form a new self-sealing gasket, prior to the time that the spike 20 punctures the hole 2c in receptacle 2. Thus, as the spike 20 is withdrawn, viscous material 30 can flow directly into the conduit 11 past the now sealed channel 24. It should also be noted that the provision of the non-stick plate member 21 affords the additional advantage of providing means for readily preventing the successively loaded receptacles 2 from being supported on irregular deposits of material that might drip from the aperture 2c in the previously removed receptacle, since any such deposits of material that hit the non-stick surface 21b of plate member 21 may be easily wiped away before the next receptacle is loaded into its supplying position.

Those skilled in the art will recognize that various modifications and improvements of the invention may be made in it based upon the disclosure presented herein; accordingly, it is my attention to encompass within the following claims the true spirit and scope of the invention.

Claims

What I claim and desire to secure by letters patent of the United States is:

1. A self-sealing, viscous material dispenser loading apparatus adapted to receive cartridge-type receptacles, comprising a frame having a receptacle supporting surface, a cartridge-type receptacle containing viscous material, means defining a discharge passageway through said surface of the frame, a conduit connected in sealed relationship to the frame and in communication with said passageway thereby to receive viscous material discharged through the passageway, a plate member mounted on the supporting surface, means defining an aperture through a generally central portion of the plate member said aperture being positioned in communication with said passageway and being operable to receive a flow of viscous material from the receptacle, said plate member having a first surface that is substantially complementary to the receptacle-supporting surface of the frame on which it is mounted and having a second surface that is formed to coact with a surface of said receptacle removably positioned thereon to form a channel therewith, one of said coacting surfaces being provided with a plurality of spaced-apart bosses that engage the other coacting surface thereby to determine the height of said channel adjacent the bosses, said bosses being no greater than one-fourth inch in height and being effective to restrict flow of viscous material in the channel sufficiently to cause it to be cured to form a sealing gasket by exposure to air within a pre-determined portion of the area of said surface of the receptacle, said second surface of the plate member being formed of a material taken from the group consisting essentially of fluorinated polymers with at least two fluorine atoms per repeating unit of the monomer (such as tetrafluoroethylene and polytetrafluoroethylene), polyethylene, polyoxymethylene, polypropylene and non-plasticized polyvinyl chloride resins, said second surface being effective to prevent the receptacle mounted thereon from being firmly bonded to the plate member or the frame by viscous material that is discharged from the receptacle into said conduit and said channel, and means for puncturing a hole in the receptacle in communication with said discharge passageway after the receptacle is positioned with the aforesaid pre-determined portion of the surface thereof in coacting relationship with said second surface of the plate member and means for forcing the viscuous material from said receptacle into said chamber and through said aperture and passageway into said conduit.

2. An invention as defined in claim 1 wherein the plate member is releasably secured in fixed position to the frame by securing means (22-22').

3. An invention as defined in claim 2 wherein the plate member is generally disc-shaped and is secured to the frame by a plurality of bolts disposed, respectively, in apertures through the plate member at spaced-apart points adjacent the periphery thereof.

4. An invention as defined in claim 2 wherein said first and second surfaces of the plate member are both generally flat, and wherein said pre-determined portion of the area of the receptacle surface is generally disc-shaped having a radius of at least 1 inch.

5. An invention as defined in claim 4 wherein the radius of said pre-determined portion is in the range of 1 to 4 inches and the height of said bosses is in the range of one thirty-second to one-eighth inch.

6. An invention as defined in claim 4 wherein said plate member and the first and second surfaces thereof are formed of one substantially homogeneous material taken from said group.

7. An invention as defined in claim 1 wherein the plate member is fused to the frame.

8. An invention as defined in claim 1 wherein said bosses are formed on said surface of the receptacle and wherein said bosses are less then one-eighth inch in height measured on their vertical axes relative to said frame.

9. An invention as defined in claim 8 wherein said coacting surface on the receptacle is surrounded by a raised lip that protrudes therefrom parallel to the vertical axes of said bosses, said lip being at least twice as high as said bosses.

10. An invention as defined in claim 9 wherein said lip closely surrounds said plate member when the receptacle is positioned on the plate member.

11. An invention as defined in claim 10 wherein said plate member is thicker than the height of said lip on the receptacle thereby to space the lip from the frame.

12. An invention as defined in claim 1 wherein said means for puncturing a hole comprises a spike reciprocally mounted for movement through said passageway to puncture a hole in said surface of the receptacle after it is mounted on the plate member, said spike being operable to force viscous material accumulated in said passageway into said channel to form a seal between the receptacle and the plate member before a hole is punctured in the receptacle.

13. An invention as defined in claim 12 including a hydraulically actuated piston operably connected to drive said spike in its reciprocal movement, said piston being mounted in a hydraulic or air cylinder and in air-tight relationship to said conduit.