Plunger for sealant dispensing cartridge with collapsible sealant enclosure

Abstract

Disclosed is a plunger (50) for use in a sealant dispensing cartridge having a collapsible sealant package (40). The plunger includes an anti-bypass retainer (60) to reduce or prevent undesirable passage of flexible sealant package around the edges of the plunger during sealant dispensing operations.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 090,991, filed October 13, 2020, which is incorporated herein by reference. Technical Field

[0003] This invention relates to plungers for use in sealant dispensing systems having collapsible sealant encapsulation. Background Technology

[0004] Adhesives and sealants are conventionally dispensed from disposable cartridges using a pneumatic dispensing gun. Collapsible sealant encapsulations have been proposed that occupy less space during transport and after sealant dispensing from the collapsible encapsulation. Variable dimensions of the plunger and cartridge sleeve can alter dispensing performance, incorporating undesirable bypasses of a portion of the collapsible encapsulation around the plunger. Summary of the Invention

[0005] This document discloses a plunger assembly for use in a sealant dispensing cylinder, comprising: a plunger including a substantially cylindrical body and a front end; and an anti-bypass retainer contacting the plunger, the anti-bypass retainer including a front portion and an anti-bypass edge, the anti-bypass edge being structured and arranged to extend radially outward when a force is applied to the front portion.

[0006] This document also discloses a sleeve and plunger assembly for use in a sealant dispensing cylinder, comprising: a sleeve; a plunger including a substantially cylindrical body and a front end; and an anti-bypass retainer contacting the plunger, the anti-bypass retainer including a front portion and an anti-bypass edge, the anti-bypass edge being structured and arranged to extend radially outward when a force is applied to the front portion.

[0007] This document further discloses a sealant dispensing system comprising: a collapsible sealant encapsulation including a rigid front end having a front opening and a flexible sidewall extending rearward from the rigid front end; an inner sleeve structured and arranged to receive the flexible sidewall; and a plunger having an anti-bypass retainer inserted into the inner sleeve, the anti-bypass retainer being structured and arranged to slide forward along the longitudinal axis of the inner sleeve and press against the rear end of the flexible sidewall when air pressure is applied to the rear surface of the plunger. Attached Figure Description

[0008] Figure 1 This is an exploded side view showing the components of a pre-loaded sealant dispensing system including a plunger with an anti-bypass retainer according to the present invention.

[0009] Figure 2This is a side view of the sealant dispensing sleeve and front cover assembly in which the plunger of the present invention with an anti-bypass retainer is inserted.

[0010] Figure 3 Is it through Figure 2 The cross-sectional view taken from line 3-3.

[0011] Figure 4 It can be included in Figure 2 Side view of the collapsible sealant encapsulation within the sleeve and the plunger with an anti-bypass retainer.

[0012] Figure 5 This is an isometric view of the plunger with an anti-bypass retainer of the present invention and Figure 6 It is a side view.

[0013] Figure 7 Is it through Figure 6 The cross-sectional view of the plunger taken from line 7-7.

[0014] Figure 8 This is an isometric view of the anti-bypass retainer component of the present invention and Figure 9 It is the front-end view.

[0015] Figure 10 Is it through Figure 9 The cross-sectional view taken from line 10-10.

[0016] Figure 11 yes Figure 10 A magnified view of a portion of the image.

[0017] Figure 12 This is an isometric view of the retainer mounting post of the present invention and Figure 13 It is a side view.

[0018] Figure 14 Is it through Figure 13 The cross-sectional view taken from line 14-14.

[0019] Figure 15 yes Figure 14 A magnified view of the portion.

[0020] Figure 16 This is a side view of a sealant dispensing sleeve and front cover assembly including the plunger with an anti-bypass retainer of the present invention.

[0021] Figure 17 Is it through Figure 16 The cross-sectional view taken from line 17-17.

[0022] Figure 18 It can be included in, for example Figure 16 The side view shown is of a collapsible sealant encapsulation within a dispensing sleeve and a plunger with an anti-bypass retainer.

[0023] Figure 19 This is a side view of a sealant dispensing sleeve and front cover assembly including the plunger with an anti-bypass retainer of the present invention.

[0024] Figure 20 Is it through Figure 19 The cross-sectional view taken from line 20-20.

[0025] Figure 21 It can be included in, for example Figure 19 The side view shown is of the collapsible sealant encapsulation and anti-bypass plunger within the distribution sleeve.

[0026] Figure 22 This is a side cross-sectional view of the rear-mounted sealant dispensing retaining sleeve with a front vent hole and an inner sleeve with a front vent notch inserted into the retaining sleeve according to the present invention. Detailed Implementation

[0027] Figure 1 A pre-attached adhesive and sealant dispensing system 10 with a plunger having an anti-bypass retainer, which can be incorporated into the present invention, is shown. The dispensing system 10 includes a generally cylindrical outer retaining sleeve 12 having a front end 13 and a rear end 14. A rear retaining pin 16 is disposed near the rear end 14 of the outer retaining sleeve 12. The dispensing system 10 includes a front cover assembly 20 with a collar 21 having external threads 22. The collar 21 can be attached to the outer retaining sleeve 12 by adhesive and / or press fit. The front cover assembly 20 includes a removable front cover 24 with an edge 25 having internal threads 26 that thread-engage with the external threads 22 of the collar 21. The removable front cover 24 has a hemispherical dome shape 27 and a front opening 28. Although... Figure 1 A specific dispensing system 10 is shown, but it should be understood that the plunger with the anti-bypass retainer of the present invention can be used with any other suitable dispensing system for collapsible sealants.

[0028] Typically, a cylindrical inner sleeve 30 fits within an outer retaining sleeve 12. The sleeve 30 includes a front end 31 and a rear end 32 with a retaining flange 34. A collapsible sealant encapsulation, for example, in the form of a cartridge 40 containing adhesive or sealant with flexible sidewalls 45, is located within the sleeve 30 and front cover assembly 20. The collapsible sealant encapsulation 40 includes a dome-shaped rigid front end 41 with a front tip 42 and a front opening 43. The rigid front end 41 has a rear edge 44. The collapsible sidewalls 45 of the cartridge 40 have a rear end 46. Uncured adhesive or sealant can be filled into the cartridge 40 and subsequently dispensed from the cartridge.

[0029] A plunger 50 with an anti-bypass retainer 60 is located within a sleeve 30. The tolerances or fits between the sleeve 30 and the plunger 50 and retainer 60, as well as the materials used to fabricate the sleeve 30, plunger 50, and retainer 60, can be selected to allow the plunger 50 to move relative to the sleeve 30 under air pressure applied by a conventional pneumatic gun, while providing a sufficiently tight seal that prevents air from passing between the interfaces of the sleeve 30 and the plunger 50. As described more fully below, the plunger 50 includes a front anti-bypass retainer 60 that presses against the rear end 46 of the flexible sidewall 45 of the sealant package 40. The retainer 60 can be radially expanded in a manner that prevents the collapsible package 40 from bypassing around the retainer 60 and the plunger 50. This expansion of the retainer 60 prevents the flexible sidewall 45 of the collapsible package 40 from bypassing around the plunger 50, which could otherwise cause slow leakage of sealant beyond the front nozzle during the dispensing process.

[0030] Figures 2 to 4 Show Figure 1 Features include an inner sleeve 30, a collapsible sealant encapsulation 40, a plunger 50, and an anti-bypass retainer 60. (As in...) Figure 3 As most clearly shown, the plunger 50 has a cylindrical body 52, a front end 53, a dome-shaped transition portion 54 between the body 52 and the front end 53, and a rear end 56. A pneumatic sealing ring 57 is provided at the rear end 56.

[0031] The bypass retainer 60 includes a front dome 61 with divided side sections and a bypass retainer edge 62 that can be radially offset outward, as described more fully below. The retainer 60 includes a central axial hole 64 and a slot 65 through the sidewalls of the front dome 61 and the edge 62. The shape of the front dome 61 can be selected to substantially conform to the hemispherical dome 27 of the front cover assembly 20.

[0032] Further details of the plunger 50 and the bypass retainer 60 are in Figures 5 to 11 As shown in the diagram. The plunger 50 includes a front end 53 that partially extends into the internal volume of the retainer 60. (As shown...) Figure 10 and 11 As shown, the retainer edge 62 includes an angled anti-bypass lip 63 extending radially outward from the edge 62. The shape and size of the anti-bypass lip 63 are chosen to allow the flexible sidewalls 45 of the collapseable package 40 to collect in a relatively organized manner, such as folding or delaminating when the package collapses during dispensing. The retainer edge 62 and lip 63 thus contact the collapseable package and help prevent it from sliding around the anti-bypass retainer 60.

[0033] like Figures 5 to 7As shown in Figures 12 to 15, the bypass retainer 60 includes a retainer attachment post 70 comprising a cylindrical body 71 and a flange 72. An attachment ring 73, which may be provided for ultrasonic welding purposes, is provided on the rear of the flange 72. A central axial hole 76 extends through the attachment post 70, and a retaining lip 78 is provided on the front end of the cylindrical body 71.

[0034] During the sealant dispensing operation, the plunger 50 and retainer 60 are typically forced axially forward within the inner sleeve by pneumatic pressure. This forward movement of the plunger 50 and retainer 60 forces the retainer 60 to press against the flexible sidewall 45 of the collapsible sealant package 40. The collapsible sealant package 40 and the uncured sealant contained therein provide a reaction force against the retainer 60, which can cause the front dome 61 and retainer edge 62 to flex radially outward, and can cause the front portion of the front dome 61 to slide axially rearward on the cylindrical body 71 of the retainer attachment post 70. The outer diameter of the retainer edge 62 can be equal to or smaller than the outer diameter of the plunger 50 before contacting the flexible sidewall 45 of the collapsible package 40. This allows free upward or downward movement via the inner sleeve 30 for initial loading of the plunger 50 and retainer 60, and for reloading of new collapsible packages. For reloading a new collapsible package, the resistance provided by the plunger 50 and retainer 60 is relatively small, thus requiring less force from the operator to slide the new collapsible package within the inner sleeve 30. Pressure from the collapsible package 40 pushes the bypass retainer 60 downward near the front opening 64, thereby forcing the retainer edge 62 and lip 63 radially outward. The dome geometry of the plunger 50 also provides support and guidance for the retainer 60 to move radially outward into the inner sleeve 30.

[0035] After deformation of the bypass retainer 60, the lip 63 and edge 62 can be pressed against the inner diameter of the inner sleeve 30 with a force of about 10%, 20%, or 30% compared to the level of pneumatic pressure applied to the rear of the plunger 50.

[0036] Figures 16 to 18 Another plunger 150 and a bypass retainer 160 of the present invention are shown. For example... Figure 17 The most clearly shown, Figure 7Many features shown are the same, except for the closed retainer front wall 67 disposed in the front dome 61 of the anti-bypass retainer 160. The retainer attachment disc 80 is fastened between the front end 53 of the plunger 50 and the front wall 67 of the retainer 160. The retainer attachment disc 80 can be fastened by any suitable means, such as adhesives, ultrasonic welding, mechanical fasteners, and the like. The retainer attachment disc 80 can generally be cylindrical and can be made of elastic or flexible materials, such as polyurethane, polyethylene, silicone foam, or the like. When the retainer attachment disc 80 is made of an elastic material, the front dome 61 can be used with… Figure 7 The front dome 61 shown in the diagram flexes in a similar manner. Figure 17 The force applied to the edge 62 and lip 63 shown can be similar to Figure 7 The force described therein.

[0037] Figures 19 to 21 This invention also illustrates another plunger 250 and an anti-bypass retainer 260. Many components are associated with... Figure 7 and 17 The same as shown in the image. Figure 20 As shown, the solid retainer front wall 68 is located at the front of the dome 61, and the open space 90 is located between the front of the plunger 53 and the retainer front wall 68. The bypass retainer 260 can contact the plunger 250, but is not otherwise secured to the plunger. During operation, the bypass retainer 260 and the plunger 250 are in contact with... Figure 7 and 17 A similar approach works, but the retainer floats freely against the plunger 250 instead of being mechanically fastened to the plunger.

[0038] Figure 22 A rear-mount external retaining sleeve 112 is shown that can be used with conventional rear-mount sealant dispensing systems known to those skilled in the art. The rear-mount external retaining sleeve 112 includes a rear retaining pin 16 and a generally dome-shaped front end 114 having a central front opening 115 through which the tip 42 of a collapsible sealant encapsulation 40 can extend. A plurality of front vent holes 116 are provided adjacent to the front end 114 of the external retaining sleeve 112. Although... Figure 22 The diagram shows four vent holes 116 equally spaced at 90° intervals around the circumference of the outer retaining sleeve 112, but it should be understood that any other suitable number, arrangement, spacing, shape and size of vent holes may be used, such as 1 to 10 or more vent holes.

[0039] like Figure 22 The image further shows that the inner sleeve 30 is inserted into the retaining sleeve 112. The inner sleeve 30 includes a front end 31, a rear end 32, and a retaining flange 34. A plurality of front venting recesses 36 are provided in the front end 31 of the inner sleeve 30. Although... Figure 22 The diagram shows four venting recesses 36 evenly spaced at 90° intervals around the circumference of the inner sleeve 30, but it should be understood that any other suitable number, arrangement, spacing, shape, and size of venting recesses may be used, such as 1 to 10 or more venting recesses. Figure 22 The opening is shown, or it can be closed, for example, it can take the form of a through hole extending through the side wall of the inner sleeve near the front end 31.

[0040] The vent recess 36 provides an airflow path from the interior of the inner sleeve 30 containing the sealant-encapsulated collapsible sidewall 45, thereby venting pressurized air that might otherwise remain trapped within the inner sleeve 30. The vent port 116 of the outer retaining sleeve 112 is in airflow communication with the vent recess 36 of the inner sleeve 30, thereby facilitating the escape of pressurized air from the inner sleeve 30 to the atmosphere. The vent recess 36 and the vent port 116 can be aligned with each other, for example by providing features on the inner sleeve 30 and / or the outer retaining sleeve 112 that provide such alignment. Alternatively, the vent recess 36 and the vent port 116 may not necessarily be aligned with each other, in which case air can pass through the space between the outer surface of the inner sleeve 30 and the inner surface of the outer retaining sleeve 112 and then be discharged through the vent port 116. Although Figure 22 The venting recess 36 is shown in the inner sleeve, but a similar venting recess 36 can be provided in the inner sleeve of a pre-installed sealant dispensing system, for example... Figure 1 The system 10 shown has an internal sleeve 30. Undesirable air pressure buildup within the internal sleeve 30 of such a front-mounted system can escape to the atmosphere through the exhaust recess 36 and the open space of the removable front cover 24.

[0041] Air vented from the internal volume of the inner sleeve 30 enables controlled collapse of the flexible sidewalls 45 of the collapsible package 40 during sealant dispensing operations, for example, by ensuring that the rear end 46 of the collapsible sidewall 45 is pushed forward by the plunger 50 and the bypass retainer 60 to dispense sealant through the front opening 43, rather than allowing pressurized air to directly press against the sidewall 45. Such undesirable air pressure against the sidewall 45 would cause it to contract in the middle, trapping a portion of the sealant and preventing it from flowing through the front opening 43. Air venting provided by the vent notch 46 can also reduce or prevent unwanted sealant discharge or dripping that might otherwise occur at the end of the dispensing operation after the air pressure against the rear side of the plunger 50 is removed.

[0042] Retainers 12 and 112 can be made of any suitable rigid material, such as metal, plastic, and the like. For example, retainers 12 and 112 can be made of steel or aluminum. Viewing slots (not shown) may optionally be provided through retainers 12 and 112, for example, extending parallel to the longitudinal axis of retainers 12 and 112. Front cover assembly 20 can be made of any suitable material, such as plastic or metal. For example, the front cover assembly can be made of a polymer, such as nylon. Sleeve 30 and plunger 50 can be made of any suitable material, such as polyethylene, polyurethane, polypropylene, or the like, for example, plastic. Plastic sleeve 30 may be slightly elastic or flexible and may have a lower thermal conductivity than retainers 12 and 112, i.e., to provide insulation.

[0043] The flexible sidewalls 45 of the barrel 40 can be made of a relatively thin sheet of laminated foil or any other suitable type of collapsible material. The dome-shaped rigid front end 41 can be made of a relatively rigid material, such as plastics and the like. For example, the rigid front end 41 and the tip 42 can be made of a polymer, such as polyethylene. The sealant contained in the barrel 40 can be any suitable sealant or adhesive formulation known to those skilled in the art, such as those used in the aerospace industry.

[0044] The retainer system of the present invention can be used with standard adhesive and sealant guns known to those skilled in the art, including, but not limited to, pneumatically driven guns sold under the names Semco Model 250-A, Model 250-B, and Model 350.

[0045] like Figure 1 The front-loading sealant dispensing system 10 shown can be loaded via the following steps: removing the front cap 24 from the retainer 12 by rotating the cap counterclockwise; removing and properly discarding the used flexible cartridge 40; loading a new flexible cartridge 40 through the front of the retainer 12 and sleeve 30, pushing the plunger 50 and retainer 60 back into the sleeve 30; placing the front cap 24 back onto the retainer 12 and securing it, for example, by turning clockwise until tightened; ready for dispensing. Figure 22 The rear-mounted sealant dispensing retainer sleeve 112 and the inner sleeve 30 with a front vent notch 36 shown can be loaded in a conventional manner known to those skilled in the art.

[0046] It should be understood that the invention may take various alternative variations and sequences of steps, unless otherwise expressly specified. Furthermore, except in any operational instance, or where otherwise indicated, all numbers, such as those expressing values, quantities, percentages, ranges, subranges, and fractions, may be considered to begin with the word “about,” even if the term is not explicitly stated. Therefore, unless otherwise indicated, the numerical parameters listed in the following description and the appended claims are approximate values ​​that may vary according to the desired properties obtained according to the invention. At least, and without attempt to limit the application of the equivalence principle to the scope of the claims, each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying ordinary rounding techniques. In cases where closed or open numerical ranges are described herein, all numbers, values, quantities, percentages, subranges, and fractions within or covered by the numerical range are considered to be specifically included in and belong to the original disclosure of this application, as if all such numbers, values, quantities, percentages, subranges, and fractions have been expressly stated.

[0047] Although the numerical ranges and parameters describing the broad scope of this invention are approximate, the values ​​described in specific examples are reported as precisely as possible. However, any numerical value inherently contains some error that is necessarily caused by the standard deviation found in their respective test measurements.

[0048] As used herein, unless otherwise stated, plural terms may encompass their singular counterparts, and vice versa, unless otherwise stated. Furthermore, in this application, unless otherwise expressly stated, the use of “or” means “and / or”, even if “and / or” may be explicitly used in certain situations.

[0049] As used herein, the terms “comprising,” “containing,” and similar terms are understood in the context of this application to be synonymous with “including,” and are therefore open-ended, and do not exclude the presence of additional undescribed or unlisted elements, materials, ingredients, or method steps. As used herein, “consisting of…” is understood in the context of this application to exclude the presence of any unspecified elements, ingredients, or method steps. As used herein, “consisting substantially of…” is understood in the context of this application to include the specified elements, materials, ingredients, or method steps, “as well as those elements, materials, ingredients, or method steps that do not materially affect the described essential and novel characteristics.”

[0050] While specific embodiments of the invention have been described in detail, those skilled in the art will understand that various modifications and alternatives to those details can be developed based on the general teachings of this disclosure. Therefore, the specific arrangements disclosed are intended to be illustrative rather than restrictive regarding the scope of the invention.

Claims

1. A plunger assembly for use in a sealant dispensing cylinder, comprising: A plunger, comprising a generally cylindrical body and a front end; as well as An anti-bypass retainer that contacts the plunger, the anti-bypass retainer including a front portion and an anti-bypass edge configured and arranged to extend radially outward when a force is applied to the front portion; Wherein, before the force is applied to the front portion, the outer diameter of the anti-bypass edge is less than or equal to the outer diameter of the plunger, and wherein, after the force is applied to the front portion, the outer diameter of the anti-bypass edge is equal to or greater than the outer diameter of the plunger; and The bypass retainer is configured and arranged to allow airflow between the front surface and the rear surface of the bypass retainer.

2. The plunger assembly of claim 1, wherein the front end of the plunger is dome-shaped.

3. The plunger assembly according to any one of claims 1 and 2, wherein at least a portion of the anti-bypass retainer includes a slot extending therethrough, thereby forming a separate segment around the circumference of the anti-bypass retainer.

4. The plunger assembly of claim 3, wherein the slot extends through the sidewall of the front portion of the anti-bypass retainer and through the anti-bypass edge.

5. The plunger assembly according to any one of claims 1 and 2, wherein the anti-bypass retainer's anti-bypass edge includes a radially outwardly extending, angled annular anti-bypass lip.

6. The plunger assembly according to any one of claims 1 and 2, wherein the anti-bypass retainer is fastened to the plunger by a retainer attachment post, the retainer attachment post comprising a rear flange attached to a front end of the plunger and a cylindrical body extending axially forward from the rear flange in contact with the anti-bypass retainer.

7. The plunger assembly of claim 6, wherein the anti-bypass retainer includes a central axial bore that slidably receives a portion of the cylindrical body of the retainer attachment post.

8. The plunger assembly of claim 7, wherein the retainer attachment post includes a retaining lip at its front end, the retaining lip being configured and arranged to retain the anti-bypass retainer on the cylindrical body of the retainer attachment post.

9. A sleeve and plunger assembly for use in a sealant dispensing cylinder, comprising: Sleeve; as well as The plunger assembly according to any one of claims 1 to 8 is disposed in the sleeve.

10. The combination of claim 9, wherein the plunger includes a pneumatic sealing ring that contacts the inner surface of the sleeve.

11. The combination according to any one of claims 9 to 10, wherein during the application of the force to the front portion of the anti-bypass retainer, the outer diameter of the anti-bypass edge of the anti-bypass retainer is equal to the inner diameter of the sleeve.

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