Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
  • F16F9/02—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using gas only or vacuum
  • F16F9/0209—Telescopic
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
  • F16F9/32—Details
  • F16F9/36—Special sealings, including sealings or guides for piston-rods
  • F16F9/368—Sealings in pistons
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
  • F16F9/32—Details
  • F16F9/48—Arrangements for providing different damping effects at different parts of the stroke
  • F16F9/483—Arrangements for providing different damping effects at different parts of the stroke characterised by giving a particular shape to the cylinder, e.g. conical
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
  • F16F2224/00—Materials; Material properties
  • F16F2224/04—Fluids
  • F16F2224/046—Fluids pneumatic

Definitions

• the present invention relates to an improved gas spring, and more
• the gas spring shaft may be selectively stopped at one or more positions
• gas springs include, among
• a tube or cylinder that defines an internal tubular cavity
• the projecting end of the shaft may extend or retract at a nominal rate through its normal stroke due to the metering of the gas across the piston assembly.
• the movement of the gas spring shaft has been decelerated - during the extension stroke of the gas spring and before the shaft is extended fully mechanically stopped by including a higher viscosity fluid in the tubular cavity.
• the inclusion of such fluid causes the piston assembly to slow incrementally and provides an end-of-travel "cushioned" stop.
• This use of the higher viscosity fluid to achieve end-of-travel damping is, however, orientation sensitive.
• the gas spring must be in a shaft-down orientation through its extension stroke or else the higher viscosity fluid will meter through the metering piston assembly prematurely, and the end-of-travel damping feature is lost.
• the spring or more particularly the
• the extending movement may be decelerated under certain circumstances before coming to a mechanical stop
• gas spring having novel structure that enables the gas spring to be capable of having the shaft make an intermediate stop(s) at one or more positions during
• Another object of the present invention is to provide an improved gas
• stop piston also includes a novel second piston assembly (called the "stop piston
• Still another object of the present invention is to provide an improved
• a further object of the present invention is to provide an improved gas
• gas spring of the type described where the gas spring may be manufactured for sale at an acceptable price (particularly in the highly competitive price
• a still further object of the present invention is to provide an improved
• a related object of the present invention is to provide an improved gas
• a still further related object of the present invention is to provide a gas spring of the type
• piston assembly remains substantially adjacent to a first section of the tubular
• FIGURE 1 illustrates the use of an improved gas spring of the present invention
• FIGURE 2 is similar to the illustration of FIGURE 1 but where the lift
• FIGURE 3 is an axial, cross-sectional view of one embodiment of an
• FIGURE 4 is an enlarged, cross-sectional view of the stop piston
• FIGURE 5 is a cross-sectional view, similar to FIGURE 4, showing the flow path of gas passing across the stop piston assembly and the metering
• FIGURE 6 is a cross-sectional view, similar to FIGURE 4, showing the
• FIGURE 7 is a cross-sectional view, similar to FIGURE 4, showing the flow path of the gas across the stop piston assembly and the metering piston
• FIGURE 8 is an enlarged cross-sectional view of the stop piston
• damping function may be achieved during a compression stroke of the gas
• FIGURE 9 is a cross-sectional view, similar to FIGURE 3, of the presently most preferred embodiment of a gas spring of the present invention.
• FIGURES 10-12 are cross-sectional views of an illustrative tube, a
• spring (indicated generally at 20) of the present invention may be employed to hold the lift gate 22 of a hatchback automobile 24 in a fully opened position (FIGURE 1 ) or in an intermediate or partially opened position (FIGURE 2).
• the ability to position the lift gate 22 at an intermediate position, such as shown in FIGURE 2, is a desirable "selling" feature because, for example, it permits persons of shorter stature to be able to easily lift the lift gate 22 to a position where ready access can be obtained to the rear compartment of the automobile 24 while not having to strain to reach the lift gate when trying to close the gate.
• the lift gate 22 can be moved from a closed position to the intermediate position, as shown in FIGURE 2, by opening the lift gate latch and pushing, in a normal manner, the lift gate upwardly.
• the lift gate 22 then stops at this intermediate position "automatically," that is, without any further effort on the part of the person. If for some reason it is a desire to move the lift gate from the intermediate position, shown in FIGURE 2, to the fully open position, shown in FIGURE 1 , the person need only briefly apply external force to the lift gate, and the gas spring will then move the lift gate 22 from its intermediate position to its fully open position.
• Another advantageous feature of the improved gas spring of the present invention is that the lift gate 22, whether in its intermediate or fully open position, may be returned to a closed position in the same manner and using the same force that would be required
• Gas springs of the present invention are also capable of providing end-
• the improved gas spring of the present invention incorporates a
• tubular cavity that has a variation(s) in its inside diameter or ID profiles so as to provide stopping zones or sections and/or deceleration or damping zones
• tubular cavity are varied with respect to the other section(s) or zone(s).
• the tubular cavity may initially have a uniform, "base" ID, and in certain
• the ID is preferably reduced vis-a-vis the "base" ID.
• ID profile variations are formed by expanding or be reducing the tube.
• Tube expansion or reduction may be accomplished by the use of several
• a novel piston assembly called a stop piston assembly herein, is adapted to cooperate with the reduced tube ID (when the shaft is moving in
• one direction, normally, its extension direction) section so as to provide a
• gas spring is to be employed.
• the improved gas springs of the present invention may have
• the degree of reduction of the ID in a reduced ID section relates to a reduction in the velocity of the spring's extension (or compression) rate of
• piston assembly is functionally "invisible” during the dynamic compression stroke, that is, the assembly does not cooperate with the reduced ID
• the stop piston assembly may
• this gas spring might be used as a semi- locking device, holding an object up or open and requiring a greater than normal force to initiate a closing motion. Additionally, the stop piston
• assembly could be made so that it would intentionally have a stopping function in both directions of travel, such as a bi-direction stopping function,
• tanning bed covers would have utility with, for instance, tanning bed covers.
• the novel stop piston assembly may be disposed or positioned adjacent a metering piston assembly. It is, however, presently most preferred that the stop piston
• metering piston assembly does not ever become adjacent to or in contact with a reduced ID section of the tubular cavity. So, separating the two piston
• present invention includes a cylindrical tube 28 that has a first end 32 and a
• the tube 28 includes a tubular cavity 36, which is adapted to
• conventional end cap 38 closes and seals the first end of the tube 28.
• the gas spring 26 also includes a reciprocally moveable shaft 42.
• the shaft is disposed, in part, in the tubular cavity 36 so that
• the shaft has a first end 44, which is adjacent to the first end 32 of the tube 28 and a
• a conventional bushing assembly 48 is disposed adjacent the second
• end 34 of the tube and surrounds the shaft 42 so as to provide a gas and oil seal for the shaft as the shaft reciprocally moves within the tube 28 in a
• the bushing assembly 48 includes a front bushing 52,
• the bushing 52 is generally cup-
• the washer 56 is disposed about the shaft 42 and between the right facing
• bushing 52 The optional bushing back 62 is axially spaced, rightward (as seen in FIGURE 3) from the seal 58, is disposed about the shaft, and is
• Two piston assemblies that is, a metering piston assembly 64 and a
• novel stop piston assembly 66 are both connected with and moveable with the shaft 42. More particularly, and as shown in FIGURE 3, the assembly 64 is connected with the front end 44 of the shaft.
• 64 may be of conventional design and function and serves to divide the
• tubular cavity 36 into an extension working chamber, which is between the
• the assembly 64 includes an orifice plate
• the shuttle valve 72 includes an annular recess that faces the orifice plate 68 and receives therein an O-ring 74.
• valve 72, O-ring 74 and washer 76 determine the rate at which gas can be
• stop piston assembly 66 is of novel design and
• the base ID is indicated at ID1 in FIGURE 10.
• the stop piston assembly 66 includes an annular stop seal shuttle
• valve member 78 that abuts a shoulder on the shaft 42 and is adjacent to the
• the member 78 includes a radially extending portion 80, which abuts the shaft shoulder, and a central portion 82 that projects toward the end 32 of the tube.
• the OD of the portion 80 is slightly less than the ID of
• any section of the tubular cavity, and the OD of the portion 82 is less than the
• a backing plate 84 is mounted on the shaft adjacent to the distal end of the central portion 82, that is, the end closest to the tube end
• An annular, resilient stop seal 86 is mounted about the central portion 82
• the axial length of the central portion 82 is greater than the axial thickness of the stop seal 86 so that the stop seal 86 may move or shuttle axially between a position where it
• the OD of the metal backing plate 84 is less than the OD of the seal 86
• the backing plate 84 supports or reinforces a central portion of the
• the annular outer portion 88 of the seal 86 is flexible and includes
• An O-ring 94 is mounted in the plate 84 and serves to seal about the shaft 42.
• the ID of the tubular cavity 36 may be reduced in a preselected section(s) or zone(s), such as sections 96 and 98 (whose ID's
• sections 102 shown generally
• the ID of the sections 102 (which ID's are indicated at ID1 in FIGURE 10) is selected so that the lip portion 92 cannot come into sealing
• stop piston assembly 66 has no functional effect on the operation of the gas spring.
• the stop groove 104 has an ID, which is smaller than the ID's of sections 96 and 98, and which
• the shaft will come to a cushioned stop just as the portion 80 comes into contact with the groove 104.
• FIGURES 4 and 5 illustrate how the gas in the tubular cavity 36 may pass across both the metering piston assembly 64 and the stop piston
• FIGURE 6 illustrates
• portion 92 will block the passage of the gas across or past the assembly 66
• FIGURE 7 illustrates how the gas is able to pass across
• a damping section such as sections 96 and 98, respectively.
• invention is a gas spring in which the metering piston assembly 64 is
• FIGURE 9 Such a gas spring 106 is illustrated in FIGURE 9.
• the gas spring 106 is structurally and functionally identical to the gas
• plate 84 includes an integral, annular, axially extending portion 108 that fits
• the OD of the portion 108 may be approximately the same as the OD of
• the distance or axial spacing between the assemblies 64 and 66 is selected so that, during all or as much as possible, of the stroke, the metering piston assembly 64 will remain adjacent to section 102 (that is, a
• the gas spring 106 includes an alternative,
• bushing assembly 1 10 functions, like the assembly 48, to provide a gas and
• the assembly 1 10 may be used interchangeably
• stop piston assembly 66 may be disposed on the
• the stop piston assembly 66 provides an intermediate stop and/or damping function due to the creation of a prescribed pressure differential
• the desired pressure differential is determined by the geometry of the piston
• stop seal 86 the properties of the stop seal material, and the diameter and
• the lip portion 92 will deflect and bypass at a lower pressure differential.
• the use of the plate 84 with the seal 86 allows those working in this art to "tailor" the stop piston assembly 66 for individual gas spring applications.
• seal of the present invention is a function of the location of the reduced ID
• damping functions to be "invisible” (to a user) when the shaft is moved in the
• shuttling is achieved by utilizing the difference between the
• stop section (such as section 96) so as to cause an intermediate stop in the shaft movement, an externally extending force (assuming that the stop
• piston assembly 66 is being used to function in the shaft extension direction
• 66 across a stop section 96 is a function of: the length of the stop section 96, the net effective force of the gas spring on the application such as the hatch,
• the seal 86 preferably be made from a material that has a predictable
• Such materials may include EPDM (the presently preferred material),

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Fluid-Damping Devices (AREA)
• Measuring Volume Flow (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=22531661

Family Applications (1)

Country Status (5)

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• 2000
  • 2000-08-17 WO PCT/US2000/022556 patent/WO2001014764A2/en not_active Ceased
  • 2000-08-17 EP EP00954119A patent/EP1123469A2/de not_active Withdrawn
  • 2000-08-17 CA CA002347498A patent/CA2347498A1/en not_active Abandoned
  • 2000-08-17 JP JP2001518606A patent/JP2003507684A/ja active Pending
  • 2000-08-17 AU AU66455/00A patent/AU6645500A/en not_active Abandoned

Non-Patent Citations (1)

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