Claims
- 1. An improved dispenser for a product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end from which product is dispensed and an open lower end, said dispenser comprising a follower piston slidably mounted within said lower end of the bore of said body to support said product thereabove, said piston being constructed of resilient material and comprising a face portion adapted to contact the product and a peripherally attached sidewall which has at least one integral peripheral contact band conforming to the shape of the cross section of said bore, said sidewall being adapted to virtually resiliently longitudinally extend or contract in response to axial forces exerted on said face portion with such change in length resulting in an inversely proportional virtual change in lateral dimension of said peripheral contact band, said piston being hollow with the interior surfaces of said face and said sidewall exposed to atmospheric pressure, and said contact band dimensioned to provide an interference fit within the bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, whereby application of downward axial force on said piston face tends to virtually expand the lateral dimension of said peripheral contact band thereby increasing said normal force and proportionally increasing piston resistance to rearward displacement within said dispenser, and application of upward axial force on said piston face tends to virtually decrease the lateral dimension of said peripheral contact band thereby reducing said normal force and proportionally reducing piston resistance to upward displacement therein and permitting said follower piston to move upwardly within said dispenser while maintaining a seal with the inner surfaces of said bore.
- 2. The dispenser of claim 1, wherein said follower piston sidewall further comprises at least one thin-walled, reentrant, bellows-like concavity formed thereabout.
- 3. An improved dispenser for a product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end from which product is dispensed and an open lower end, said dispenser comprising a follower piston slidably mounted within said lower end of the bore of said body to support said product thereabove, said piston being constructed of resilient material and comprising a face portion adapted to contact the product, a depending friction ring which establishes a predetermined frictional resistance to displacement of said piston within said bore in static condition, and a peripherally attached sidewall which has at least one integral peripheral contact band conforming to the shape of the cross section of said bore, said contact band dimensioned to provide an interference fit within the bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, said piston sidewall being adapted to virtually resiliently longitudinally extend or contract in response to axial forces exerted on said face portion with such change in length resulting in an inversely proportional virtual change in lateral dimension of said peripheral contact band and having at least one thin-walled, reentrant, bellows-like concavity formed thereabout, said bellows-like concavity further comprising an outwardly convex continuous depending sidewall, said depending sidewall being attached about its upper periphery to said face portion and about its lower periphery to said friction ring and having said peripheral contact band formed intermediate said face portion and said friction ring, and said piston being hollow with the interior surfaces of said face and said piston sidewall exposed to atmospheric pressure, whereby application of downward axial force on said piston face tends to virtually expand the lateral dimension of said peripheral contact band thereby increasing said normal force and proportionally increasing piston resistance to rearward displacement within said dispenser, and application of upward axial force on said piston face tends to virtually decrease the lateral dimension of said peripheral contact band thereby reducing said normal force and proportionally reducing piston resistance to upward displacement therein and permitting said follower piston to move upwardly within said dispenser while maintaining a seal with the inner surfaces of said bore.
- 4. The dispenser of claim 3, wherein said contact band of said follower piston is located at the radially largest continuous outside dimension of said outwardly convex sidewall.
- 5. An improved dispenser for a product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end from which product is dispensed and an open lower end, said dispenser comprising a follower piston slidably mounted within said lower end of the bore of said body to support said product thereabove, said piston being constructed of resilient material and comprising a face portion adapted to contact the product and a peripherally attached sidewall, the interior surfaces of said face and said sidewall being exposed to ambient air, said sidewall being formed with at least one thin-walled, reentrant, bellows-like concavity thereabout, the upper and lower extremes of said concavity each being connected to an integral peripheral contact band conforming to the shape of the cross section of the bore, said sidewall being adapted to virtually resiliently longitudinally extend or contract in response to axial forces exerted on said face portion with such change in length resulting in an inversely proportional virtual change in lateral dimension of said peripheral contact bands, said contact bands being dimensioned to provide an interference fit within the bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, whereby application of downward axial force on said piston face tends to virtually expand the lateral dimensions of said peripheral contact bands thereby increasing said normal force and proportionally increasing piston resistance to rearward displacement within said dispenser, and application of upward axial force on said piston face tends to virtually decrease the lateral dimensions of said peripheral contact bands thereby reducing said normal force and proportionally reducing piston resistance to upward displacement therein and permitting said follower to move upwardly within said dispenser while maintaining a seal with the inner surfaces of said bore.
- 6. The dispenser of claim 5, wherein said follower piston sidewall is formed with a plurality of said thin-walled, reentrant, bellows-like concavities integrally connected in seriatim by peripheral contact bands at their upper and lower extremes thereby forming a thin-walled accordion-like structure which resiliently permits said depending sidewall to be virtually longitudinally strained by axial forces, said virtual longitudinal strain resulting in inversely proportional virtual radial dimensional strain of said peripheral contact bands.
- 7. The dispenser of claim 6 wherein said face portion of said follower piston is connected about its outer periphery to the upper extreme of the uppermost bellows-like concavity by the uppermost integral peripheral contact band.
- 8. The dispenser of claims 4, 6 or 7 wherein the product-contacting side of said face portion of said follower piston is substantially convex.
- 9. The dispenser of claims 4, 6 or 7 wherein the product-contacting side of said face portion of said follower piston is substantially concave.
- 10. The dispenser of claims 4, 6 or 7 wherein the product-contacting side of said face portion of said follower piston is substantially flat.
- 11. The dispenser of claim 6, wherein said reentrant, bellows-like concavities have included angles of between about 30.degree. and about 120.degree..
- 12. The dispenser of claim 11, wherein said reentrant, bellows-like concavities each have a pitch of at least about 3.2 mm (0.125 inches).
- 13. An improved dispenser for a product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end from which product is dispensed and an open lower end, said dispenser comprising a follower piston slidably mounted within said lower end of the bore of said body to support said product thereabove, said piston being constructed of resilient material and comprising a face portion adapted to contact the product, a friction ring dimensioned to provide an interference fit within said bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, and a peripherally attached sidewall further comprising at least two oppositely disposed helical strips depending from the lower periphery of said face portion and attached at their lower ends to the upper periphery of said friction ring, said helical strips conforming to the shape of the cross section of said bore thereby establishing at least two peripheral contact bands, said sidewall being adapted to virtually resiliently longitudinally extend or contract in response to axial forces exerted on said face portion with such change in length resulting in an inversely proportional virtual change in lateral dimension of said peripheral contact bands, said piston being hollow with the interior surfaces of said face and said sidewall exposed to atmospheric pressure.
- 14. The dispenser of claim 13, wherein said follower piston further comprises two right-handed and two left-handed helical strips depending from the lower periphery of said face portion and attached at their lower ends to the upper periphery of said friction ring, each of said helical strips formed as one full helical revolution, said helical strips being connected to one another at their helical intersections thereby forming a perforated sidewall.
- 15. An improved pump-type dispenser for a fluid product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end which communicates with a discharge passageway and an open lower end, said dispenser comprising a follower piston slidably mounted within the bore of said body and sealing the same against escape of product from said lower end, said piston being constructed of resilient material and comprising a face portion adapted to contact the product and a peripherally attached sidewall, said sidewall further comprising at least one integral peripheral contact band conforming to the shape of the cross section of said bore and being adapted to virtually resiliently longitudinally extend or contract in response to axial forces exerted on said face portion with such change in length resulting in inversely proportional virtual change in lateral dimension of said peripheral contact band, said piston being hollow and the interior surfaces of said face and side sidewall being exposed to atmospheric pressure, said contact band being dimensioned to provide an interference fit within the bore which exerts a predetermined force against the inner surfaces of said bore in static condition, whereby application of pumping pressure to said product tends to virtually expand the lateral dimension of said peripheral contact band thereby increasing said normal force to prevent movement of said piston toward the open end of the bore and reduction of pressure within the product to below atmospheric tends to virtually decrease the lateral dimension of said peripheral contact band thereby reducing said normal force and permitting ambient air pressure to move said piston toward the upper end of the bore until equilibrium is reached, said piston maintaining its seal within said bore as it moves upwardly therewithin.
- 16. The dispenser of claim 15, wherein said follower piston sidewall further comprises at least one thin-walled, reentrant, bellows-like concavity formed thereabout.
- 17. The dispenser of claim 15, wherein said follower piston further comprises a depending friction ring dimensioned to provide an interference fit within said bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, and wherein said sidewall further comprises at least two oppositely disposed helical strips depending from the lower periphery of said face portion and attached at their lower ends to the upper periphery of said friction ring, said helical strips conforming to the shape of the cross section of said bore thereby establishing at least two peripheral contact bands.
- 18. A pump-type dispenser for a fluid product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end which communicates with a discharge passageway and an open lower end, said dispenser comprising a follower piston slidably mounted within the bore of said body and sealing the same against escape of product from said lower end, said piston being constructed of resilient material and comprising a face portion adapted to contact the product, a depending friction ring which establishes a predetermined frictional resistance to displacement of said piston within said bore in static condition, and a peripherally attached sidewall further comprising at least one integral peripheral contact band conforming to the shape of the cross section of said bore and having at least one thin-walled, reentrant, bellows-like concavity formed thereabout, said piston sidewall being adapted to virtually resiliently longitudinally extend or contract in response to axial forces exerted on said face portion with such change in length resulting in inversely proportional virtual change in lateral dimension of said peripheral contact band, said piston being hollow and the interior surfaces of said face and said piston sidewall being exposed to atmospheric pressure, said bellows-like concavity further comprising an outwardly convex continuous depending sidewall, said depending sidewall being attached about its upper periphery to said face portion and about its lower periphery to said friction ring and having said peripheral contact band formed intermediate said face portion and said friction ring, said contact band being dimensioned to provide an interference fit within the bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, whereby application of pumping pressure to said product increases said normal force to prevent movement of said piston toward the open end of the bore and reduction of pressure within the product to below atmospheric reduces said normal force and permits ambient air pressure to move said piston toward the upper end of the bore until equilibrium is reached, said piston maintaining its seal within said bore as it moves upwardly therewithin.
- 19. An improved pump-type dispenser for a fluid product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end which communicates with a discharge passageway and an open lower end, said dispenser comprising a follower piston slidably mounted within the bore of said body and sealing the same against escape of product from said lower end, said piston being constructed of resilient material and comprising a face portion adapted to contact the product and a peripherally attached sidewall, said piston being hollow and the interior surfaces of said face and said sidewall being exposed to ambient air, said sidewall being formed with at least one thin-walled, reentrant, bellows-like concavity thereabout, the upper and lower extremes of said concavity each being connected to an integral peripheral contact band conforming to the shape of the cross section of the bore, said contact bands being dimensioned to provide an interference fit within the bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, whereby application of pumping pressure to said product tends to virtually expand the lateral dimensions of said peripheral contact bands thereby increasing said normal force to prevent movement of said piston toward the open end of the bore and reduction of pressure within the product to below atmospheric tends to virtually decrease the lateral dimensions of said peripheral contact bands thereby reducing said normal force and permitting ambient air pressure to move said piston toward the upper end of the bore until equilibrium is reached, said piston maintaining its seal within said bore as it moves upwardly therewithin.
- 20. The dispenser of claim 19, wherein the peripherally attached sidewall of said follower piston is formed with a plurality of said thin-walled, reentrant, bellows-like concavities integrally connected by said contact bands at their upper and lower extremes thereby forming a thin-walled accordion-like structure which resiliently permits said sidewall to be virtually longitudinally strained by said pumping pressure, said virtual longitudinal strain resulting in inversely proportional virtual lateral dimension strain of said peripheral contact bands, whereby virtual lateral expansion of said contact bands results in increased normal force exerted by said contact bands against the inner surfaces of said bore, and virtual lateral compression of said contact bands results in decreased normal force exerted thereby.
- 21. The dispenser of claim 20 wherein the product-contacting side of said face portion of said follower piston is substantially convex.
- 22. The dispenser of claim 20 wherein the product-contacting side of said face portion of said follower piston is substantially concave.
- 23. The dispenser of claim 20 wherein the product-contacting side of said face portion of said follower piston is substantially flat.
- 24. The dispenser of claim 21 wherein the face portion of said follower piston is connected about its outer periphery to the upper extreme of the uppermost bellows-like concavity by the uppermost integral peripheral contact band.
- 25. The dispenser of claim 20 wherein said reentrant, bellows-like concavities have included angles of between about 30.degree. and about 120.degree..
- 26. The dispenser of claim 25, wherein said reentrant, bellows-like concavities each have a pitch of at least about 3.2 mm (0.125 inches).
- 27. An improved pump-type dispenser for a fluid product, wherein the product is housed in an axially extending bore of a tubular container body having an upper end including a resilient dispensing top having a defined pump actuation area and a dispensing outlet formed therethrough, and an open lower end, said dispenser comprising a follower piston slidably mounted within the bore of said container body and sealing the same against escape of product from said lower end, said piston being constructed of resilient material and comprising a face portion adapted to contact the product and a peripherally attached sidewall, said piston being hollow and the interior surfaces of said face and said sidewall being exposed to ambient air, said sidewall being formed with at least one thin-walled, reentrant, bellows-like concavity thereabout, the upper and lower extremes of said concavity each being connected to an integral peripheral contact band conforming to the shape of the cross section of the bore, said contact bands being dimensioned to provide an interference fit within the bore which exerts a predetermined normal force against the inner surfaces of said bore in static condition, whereby application of pumping pressure to said product increases said normal force to prevent movement of said piston toward the open end of the bore and reduction of pressure within the product to below atmospheric reduces said normal force and permits ambient air pressure to move said piston toward the upper end of the bore until equilibrium is reached, said piston maintaining its seal within said bore as it moves upwardly therewithin.
- 28. The pump-type dispenser of claim 27, wherein said dispensing outlet comprises a one-way outlet check valve attached to said resilient dispensing top.
- 29. The pump-type dispenser of claim 28, wherein said outlet check valve is oriented in a vertical direction substantially parallel to the central axis of said tubular container body.
- 30. The pump-type dispenser of claim 28, wherein said outlet check value is oriented in a horizontal direction substantially normal to the central axis of said tubular container body.
- 31. The pump-type dispenser of claim 28, wherein said outlet check valve is oriented at an oblique direction relative the central axis of said tubular container body.
- 32. The pump-type dispenser of claim 29, 30, or 31, wherein said outlet check valve is mounted on said resilient dispensing top and does not extend outwardly beyond the outer periphery of said tubular container body.
- 33. The pump-type dispenser of claim 32, wherein said dispenser includes an overcap which telescopes over the upper end of said dispenser to cover said resilient dispensing top and its outlet check valve.
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of the prior copending application entitled "Follower Device For Dispensing Package", Ser. No. 546,344, filed Oct. 31, 1983, now abandoned, in the name of James L. Drobish.
US Referenced Citations (35)
Foreign Referenced Citations (3)
Number |
Date |
Country |
2920915 |
Nov 1980 |
DEX |
875780 |
Oct 1942 |
FRX |
197618 |
Jan 1965 |
SEX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
546344 |
Oct 1983 |
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