Adjustable speed gas spring

• US 5,579,874 A
• Filed: 10/23/1995
• Issued: 12/03/1996
• Est. Priority Date: 09/13/1994
• Status: Expired due to Fees

• Current Assignee: AVM Industries, Inc.
• Original Assignee: AVM Software Incorporated (Paltalk, Inc.)
• Inventors: Jeffries, Mark S., Chamberlin, James B., Evans, Archie L.
• Primary Examiner(s): Young, Lee W.
• Application Number:
  US08/546,611
• Time in Patent Office: 407 Days
• Field of Search: 188/281, 188/282, 188/274, 188/322.15, 188/317, 188/319, 267/64.11, 267/64.25
• US Class Current: 188/282.9
• CPC Class Codes: E05F 1/1091 with a gas spring E05F1/1292 takes precedence
• CPC Class Codes: E05F 1/16 for sliding wings
• CPC Class Codes: E05F 3/02 with pneumatic piston brakes rotary type E05F3/14
• CPC Class Codes: E05Y 2201/25 Force or torque adjustment therefore E05Y2400/21 takes precedence
• CPC Class Codes: E05Y 2900/132 Doors
• CPC Class Codes: F16F 9/02 using gas only or vacuum F16F9/006 takes precedence
• CPC Class Codes: F16F 9/0227 characterised by the piston construction
• CPC Class Codes: F16F 9/0263 characterised by actuation means, e.g. manually-operated lever arrangement F16F9/0254 takes precedence
• CPC Class Codes: F16F 9/462 Rotary actuation means
• CPC Class Codes: F16F 9/516 resulting in the damping effects during contraction being different from the damping effects during extension , i.e. responsive to the direction of movement F16F9/504 takes precedence

Abstract

An adjustable speed gas spring primarily adapted for use as a part of a door closing mechanism. The gas spring includes a piston assembly which is disposed within an elongated fluid chamber and which upon relative rotation of the shaft with respect to the tubular body, permits the user to adjust the shaft extension velocity. The gas spring is fully functional in any shaft orientation.

Claims

1. An adjustable speed gas spring adapted for assisting in closing a door in a building where the gas spring velocity in at least one direction determines the closing speed of the door, the gas spring comprising:

a tubular body having an inner wall that defines an elongated fluid chamber therein, the fluid chamber having a first end and a second end and also having a longitudinal axis that extends between the first and second ends, with the first and second ends of the fluid chamber each having normally closed openings therein, with the fluid chamber being filled with at least a first pressurized fluid, and with the second end of the body adapted to be connected with selectively one of the building adjacent to the door and the door;

a shaft having a central axis, a first end and a second end, with the first end of the shaft having a shoulder thereon and extending into the first end of the fluid chamber so that the axes of the fluid chamber and the shaft are coaxial and so that the first end of the shaft may reciprocally move in the fluid chamber parallel to the axis of the fluid chamber, and with the second end of the shaft adapted to be connected with selectively the other of the door or the building adjacent to the door, and with the shoulder being adjacent to the first end of the shaft;

a first piston assembly supported on and about the shaft adjacent the first end of the shaft and serving to separate the fluid chamber into a first sub-chamber that is adjacent the first end of fluid chamber and a second sub-chamber that is adjacent to the second end of the fluid chamber, the first piston assembly including;

(a) a sub-assembly that has a first side facing one end of the fluid chamber, that has a second side facing the other end of the fluid chamber and that has an axial opening through which the first end of the shaft extends;

(b) a first flow path and a second fluid flow path, with a part of both the first and second flow paths being disposed, in part, in the sub-assembly and extending between the first and second sub chambers, and with the first flow path providing less restriction to the flow of fluid than the second flow path;

(c) a first member connected with the first end of the shaft so as to move therewith, with the first member having a first side that faces the one end of the fluid chamber and that is adjacent to the second side of the sub-assembly, with another part of the second flow path being defined between the second side of the sub-assembly and the first side of the first member and with the relative angular positioning of the second side of the sub-assembly and first side of the first member determining the flow area of the other part of the second flow path; and

means for permitting the shaft and selectively one of the sub-assembly and the first member to be rotated relative to each about the axis of the shaft such that the relative rotation will cause relative rotational movement between the second side of the sub-assembly and the first side of the first member of the sub-assembly so as to cause the flow area of the other part of the second flow path to be changed.

2. The gas spring of claim 1 wherein a second member is supported on the first end of the shaft adjacent to the first side of the sub-assembly, with the sub-assembly being supported on the shaft between the first and second members, and with the distance between first and second members, parallel to the axis of the shaft, being greater than the distance between the first and second sides of the sub-assembly so that the sub-assembly may move axially, along the axis of the shaft, relative to the first member.

3. The gas spring of claim 2 wherein the second side of the sub-assembly and the first side of the first member are generally parallel to each other and are moved into surface-to-surface contact with each other when the first end of the shaft moves relatively toward the other end of the fluid chamber;

wherein the other part of the second flow path includes a groove which is formed in selectively one of the second side of the sub-assembly and the first side of the first member.

4. The gas spring of claim 1 wherein the other part of the second flow path includes a radially extending groove which is formed in selectively one of the second side of the sub-assembly and the first side of the first member;

and wherein the first member has an involute-like spiral profile.

5. The gas spring of claim 1 wherein a plurality of angularly spaced slots that are in selectively one of the second side of the sub-assembly and the first side of the first member, with each of the plurality of slots having different flow areas, with the other slot being adopted to be selectively aligned with one of the plurality of slots;

wherein another slot is in selectively the other one of the second side of the sub-assembly and the first side of the first member; and

wherein the other part of the second flow path includes the other slot and an aligned one of the plurality of slots.

6. The gas spring of claim 5 which includes means for selectively maintaining the other slot aligned with the one of the plurality of slots.

7. The gas spring of claim 5 which includes means for indicating which one of the plurality of slots is aligned with the other slot.

8. In an adjustable speed gas spring which is adapted for assisting in closing a door in a building, including:

a tubular body having a first end, a second end, and an inner wall that defines an elongated fluid chamber therein, the fluid chamber having a first end adjacent to the first end of the body, a second end adjacent to the second end of the body, and a longitudinal axis that extends between the first and the second ends of the fluid chamber, with the first and second ends of the fluid chamber each having normally closed openings therein, with the fluid chamber being filled with at least a first fluid, and with the second end of the body adapted to be connected with selectively one of the building adjacent to the door and the door;

a shaft having a central longitudinal axis, a first end and a second end, with the first end of the shaft extending into the first end of the fluid chamber so that the axes of the fluid chamber and the shaft are coaxial and so that the first end of the shaft may rotate about its axis in and with respect to the body and may reciprocally move in the fluid chamber parallel to the axis of the fluid chamber, and with the second end of the shaft adapted to be connected with selectively the other of the door or the building adjacent to the door, the improvement comprising;

a first piston assembly that permits the speed of the shaft, when moved in at least one axial direction, to be adjusted in that the speed may be selectively increased or decreased, that is supported on and about the shaft adjacent to the first end of the shaft and that serves to separate the fluid chamber into a first sub-chamber which is adjacent the first end of the fluid chamber and a second sub-chamber which is adjacent to the second end of the fluid chamber;

first and second fluid flow paths defined in the first piston assembly for permitting fluid to flow between the first and second sub-chambers, with the first flow path being closed when the first piston assembly moves in the one axial direction and being open when the first piston assembly moves in the opposite axial direction;

the first piston assembly including a first member that is mounted on the shaft, adjacent to the first end of the shaft, such that the first member moves reciprocally and rotationally with the reciprocal and rotational movement of the shaft and that includes a first side thereon;

a second member that is mounted on the shaft, adjacent to the first member, that is adapted to move, in a limited manner, with respect to the first member and the shaft and that includes a second side thereon which faces the first side of the first member, with the first and second sides being adapted to define therebetween an interim fluid flow path that defines at least a part of the second fluid flow path; and

means for selectively rotating the first and second members, with respect to each other, to selectively change the interim flow path so as to selectively change the fluid pressure drop across the interim flow path when the first piston assembly moves in the one axial direction.

9. The adjustable speed gas spring of claim 8 wherein when the shaft and first piston assembly are moved in the one axial direction, the first and second sides are maintained adjacent to each other so as to define therebetween the interim fluid flow path;

and wherein when the shaft and first piston assembly are moved in the opposite axial direction, the second member is moved axially, with respect to the first member, so that a gap is created between the first and second sides and so as to non-define the interim fluid flow path between the first and second sides.

10. The adjustable speed gas spring of claim 9 wherein the interim fluid flow path includes a groove in selectively one of the first side and the second side;

and wherein selectively the other of the first side and the second side includes means for changing the effective flow length of the groove which, in turn, changes the fluid pressure drop across the interim flow path.

11. The adjustable gas spring of claim 10 wherein the first and second sides are generally annular and include central apertures through which the shaft extends;

and wherein the groove extends radially from the aperture in the side in which the groove is included.

12. The adjustable gas spring of claim 11 wherein the depth of the groove varies along its length.

13. The adjustable gas spring of claim 10 wherein the means for changing the effective flow length of the groove includes an involute-like shaped member.

14. The adjustable speed gas spring of claim 8 wherein the first and second sides are generally annular and include central apertures through which the shaft extends;

wherein the interim fluid flow path includes a plurality of slots that are in selectively one of the first and second sides, that are angularly spaced from each other about the longitudinal axis of the shaft and that selectively define a portion of the interim flow path;

wherein each of the plurality of slots differs from the other slots in terms of the fluid pressure drop created by fluid flow therethrough; and

wherein selectively the other of the first and second surfaces includes another slot that may selectively be aligned with one of the plurality of slots and that serves as a part of the interim flow path which extends between the periphery of the first and second sides and the central apertures of the first and second sides.

15. The adjustable speed gas spring of claim 8 wherein at least a part of the first flow path is defined between the inner wall of the tubular body and the first piston assembly.

16. The adjustable speed gas spring of claim 8 which includes means for selectively maintaining the other slot aligned with the one of the plurality of slots.

17. The adjustable speed gas spring of claim 8 which includes means for indicating which one of the plurality of slots is aligned with the other slot.

18. An adjustable speed gas spring adapted for assisting in closing a door in a building where the gas spring extension velocity determines the closing speed of the door, the gas spring comprising:

a tubular body having an inner wall that defines an elongated fluid chamber therein, the fluid chamber having a first end and a second end and also having an elongated axis that extends between the first and second ends, with the first and second ends of the fluid chamber each having normally closed openings therein, with the fluid chamber being filled with at least a first pressurized fluid, and with the second end of the body adapted to be connected with selectively one of the building adjacent to the door and the door;

a shaft having a central axis, a shoulder, and first and second ends, with the first end of the shaft extending into the first end of the fluid chamber so that the axes of the fluid chamber and the shaft are coaxial and so that the first end of the shaft may reciprocally move in the fluid chamber parallel to the axis of the fluid chamber, and with the second end of the shaft adapted to be connected with selectively the other of the door or the building adjacent to the door, and with the shoulder being adjacent to the first end of the shaft;

a first piston assembly supported on and about the shaft adjacent the first end of the shaft and serving to separate the fluid chamber into a first sub-chamber that is adjacent the first end of fluid chamber and a second sub-chamber that is adjacent to the second end of the fluid chamber, the first piston assembly including;

(a) a sub-assembly that has a first side facing the first end of the fluid chamber, that has a second side facing the second end of the fluid chamber, that has an axial opening through which the first end of the shaft extends, and that has a portion, between the sides, which sealingly engages the inner wall of the tubular body so as to prevent the flow of fluid between the sub-assembly and the inner wall from the first sub-chamber to the second sub-chamber and visa versa; and

(b) a first flow path and a second fluid flow path, with a part of both the first and second flow paths being disposed, in part, in the sub-assembly and extending between the first and second sub-chambers, and with the first flow path providing less restriction to the flow of fluid than the second flow path;

(c) a first member connected with the first end of the shaft so as to move therewith, with the first member having a first side that faces the first end of the fluid chamber and that is adjacent to the second side of the sub-assembly, with the first member, in cooperation with the sub-assembly, serving to restrict flow through the first flow path when the first end of the shaft moves relatively away from the second end of the first chamber and to permit flow through the first flow path when the first end of the shaft moves relatively towards the second end of the fluid chamber, with another part of the second flow path being defined between the second side of the sub-assembly and the first side of the first member and with the relative angular positioning of the second side of the sub-assembly and first side of the first member determining the length of the other part of the second flow path;

(d) a second member supported on the first end of the shaft adjacent to the first side of the sub-assembly so that the second member will limit movement of the sub-assembly, relative to the first end of the shaft, toward the second end of the shaft, with the second member being disposed on the shaft between the shoulder and the first end of the shaft, with the sub-assembly being supported on the shaft between the first and second members, and with the distance between first and second members, parallel to the axis of the shaft, being greater than the distance between the first and second sides of the sub-assembly so that the sub-assembly may move, along the axis of the shaft, relative to the first member; and

means for permitting the shaft and the tubular body to be rotated relative to each about the axis of the shaft such that the relative rotation will cause relative rotational movement between the second side of the sub-assembly and the first side of the first member so as to cause the length of the second flow path to be changed.

19. The gas spring of claim 18 wherein the second side of the sub-assembly and the first side of the first member are generally parallel to each other and are moved into surface-to-surface contact with each other when the first end of the shaft moves relatively toward the first end of the fluid chamber;

wherein the other part of the second flow path includes a curved groove which is formed in selectively one of the second side of the sub-assembly and the first side of the first member and which is spaced inwardly from their peripheral side edges, and a cut-out which is adjacent to the peripheral side edge of selectively the other of the first side of the first member and the second side of the sub-assembly and which extends inwardly from the peripheral side edge so as to overlie a portion of the groove.

20. The gas spring of claim 19 wherein the first flow path includes a plurality of axially extending passages in and axial through the sub-assembly;

wherein the one part of the second flow path includes one of the plurality of the axially extending passages wherein the ends of the axially extending passages, which are adjacent to the second side of the sub-assembly, are blocked by the first side of the first member when the first side of the first member and the second side of the sub-assembly are in surface-to-surface contact;

wherein one end of the groove is in fluid communication with the one axially extending passage so as to permit fluid to flow from the one axially extending passage into the groove when the second side of the sub-assembly and the first side of the first member are in surface to surface contact.

21. The gas spring of claim 18 wherein the first flow path includes a plurality of axially extending passages in and axial through the sub-assembly;

wherein the one part of the second flow path includes one of the plurality of the axially extending passages;

wherein the ends of the axially extending passages, which are adjacent to the second side of the sub-assembly, are blocked by the first side of the first member when the first side of the first member and the second side of the sub-assembly are in surface-to-surface contact;

wherein one end of the groove is in fluid communication with the one axially extending passage so as to permit fluid to flow from the one axially extending passage into the groove when the second side of the sub-assembly and the first side of the first member are in surface to surface contact.