US20130305915A1 - Gas strut assembly with an internal detent module - Google Patents
Gas strut assembly with an internal detent module Download PDFInfo
- Publication number
- US20130305915A1 US20130305915A1 US13/473,906 US201213473906A US2013305915A1 US 20130305915 A1 US20130305915 A1 US 20130305915A1 US 201213473906 A US201213473906 A US 201213473906A US 2013305915 A1 US2013305915 A1 US 2013305915A1
- Authority
- US
- United States
- Prior art keywords
- central axis
- strut assembly
- gas strut
- rod
- displaceable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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Classifications
-
- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05F—DEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION; CHECKS FOR WINGS; WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING
- E05F1/00—Closers or openers for wings, not otherwise provided for in this subclass
- E05F1/08—Closers or openers for wings, not otherwise provided for in this subclass spring-actuated, e.g. for horizontally sliding wings
- E05F1/10—Closers or openers for wings, not otherwise provided for in this subclass spring-actuated, e.g. for horizontally sliding wings for swinging wings, e.g. counterbalance
-
- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05C—BOLTS OR FASTENING DEVICES FOR WINGS, SPECIALLY FOR DOORS OR WINDOWS
- E05C17/00—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith
- E05C17/02—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith by mechanical means
- E05C17/04—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith by mechanical means with a movable bar or equivalent member extending between frame and wing
- E05C17/30—Devices for holding wings open; Devices for limiting opening of wings or for holding wings open by a movable member extending between frame and wing; Braking devices, stops or buffers, combined therewith by mechanical means with a movable bar or equivalent member extending between frame and wing of extensible, e.g. telescopic, construction
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- 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
-
- 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
- F16F9/0218—Mono-tubular units
-
- 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
- F16F9/04—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium using gas only or vacuum in a chamber with a flexible wall
-
- 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
- F16F9/50—Special means providing automatic damping adjustment, i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs; Special means providing self-adjustment of spring characteristics
- F16F9/52—Special means providing automatic damping adjustment, i.e. self-adjustment of damping by particular sliding movements of a valve element, other than flexions or displacement of valve discs; Special means providing self-adjustment of spring characteristics in case of change of temperature
-
- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05Y—INDEXING SCHEME RELATING TO HINGES OR OTHER SUSPENSION DEVICES FOR DOORS, WINDOWS OR WINGS AND DEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION, CHECKS FOR WINGS AND WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING
- E05Y2900/00—Application of doors, windows, wings or fittings thereof
- E05Y2900/50—Application of doors, windows, wings or fittings thereof for vehicles
- E05Y2900/53—Application of doors, windows, wings or fittings thereof for vehicles characterised by the type of wing
- E05Y2900/536—Hoods
-
- E—FIXED CONSTRUCTIONS
- E05—LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
- E05Y—INDEXING SCHEME RELATING TO HINGES OR OTHER SUSPENSION DEVICES FOR DOORS, WINDOWS OR WINGS AND DEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION, CHECKS FOR WINGS AND WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING
- E05Y2900/00—Application of doors, windows, wings or fittings thereof
- E05Y2900/50—Application of doors, windows, wings or fittings thereof for vehicles
- E05Y2900/53—Application of doors, windows, wings or fittings thereof for vehicles characterised by the type of wing
- E05Y2900/548—Trunk lids
-
- 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
- F16F2230/00—Purpose; Design features
- F16F2230/0052—Physically guiding or influencing
- F16F2230/0064—Physically guiding or influencing using a cam
Definitions
- the invention generally relates to a gas strut assembly, and more specifically to an internal detent module for increasing a hold-open force of the gas strut assembly.
- Gas strut assemblies include a housing that defines an interior space, with a rod moveably disposed within the interior space.
- the rod is slideably moveable along a central axis between a retracted position, i.e., a shortened position, and an extended position, i.e., a lengthened position.
- a piston is disposed at an axial end of the rod within the interior space of the housing.
- the housing includes a closed end, and includes a volume of gas, such as but not limited to air, trapped within the interior space of the housing, between the piston and the closed end of the housing.
- Movement of the rod from the extended position into the retracted position compresses the air between the closed end of the housing and the piston, thereby generating a resulting axial force urging the piston and the rod back into the extended position. As such, the rod is continuously biased toward the extended position.
- the gas strut assemblies are biased toward the extended position, the gas strut assemblies are often utilized to provide an opening force and/or to provide a hold-open force to door, trunk lid, hood, etc.
- the gas strut assemblies rely on the compressed gas to provide the axial force urging the piston and the rod into the extended position.
- Changing ambient temperatures change the temperature of the gas, which changes the density of the gas. For example, when the temperature decreases, the density of gas also decreases, which lowers the resulting axial force that urges the rod into the extended position.
- a gas strut assembly is provided.
- the gas strut assembly includes a housing having a wall that extends along a central axis. The wall defines an interior space.
- a rod is coupled to the housing. The rod is slideably moveable within the interior space along the central axis between an extended position and a retracted position.
- a flexible member is secured in position relative to the housing.
- a rigid member is coupled to and moveable with the rod.
- the flexible member includes at least one displaceable portion that moves radially away from the central axis in response to a first radial force component of an opening force when engaged by the rigid member moving from the retracted position into the extended position.
- the displaceable portion moves radially away from the central axis in response to a second radial force component of a closing force when engaged by the rigid member moving from the extended position into the retracted position.
- the second radial force component is greater than the first radial force component.
- the interaction between the rigid member and the flexible member resists movement of the rod along the central axis.
- the interaction between the flexible member and the rigid member In order to move the rod from the extended position into the retracted position, the interaction between the flexible member and the rigid member must generate the second radial force component from the closing force. The second radial force component must be sufficient to move the displaceable portion away from the rigid member to allow the rigid member to pass thereby and continue into the refracted position.
- the mechanical interaction between the rigid member and the flexible member increases the force required to move the rod out of the extended position and into the retracted position, thereby increasing the hold-open force of the gas strut assembly.
- the interaction between the flexible member and the rigid member In order to move the rod from the retracted position into the extended position, the interaction between the flexible member and the rigid member must generate the first radial force component from the opening force.
- the first radial force component must be sufficient to move the displaceable portion away from the rigid member to allow the rigid member to pass thereby and continue into the extended position.
- the mechanical interaction between the rigid member and the flexible member increases the force required to move the rod into the extended position.
- the interaction between the flexible member and the rigid member is designed so that the first radial force component is significantly less than the second radial force component so that the axial opening force generated from the compressed gas within the housing is able to generate the first radial force component and move the rod into the extended position.
- FIG. 1 is a schematic cross sectional view of a gas strut assembly in an retracted position.
- FIG. 2 is a schematic cross sectional view of the gas strut assembly in an extended position.
- FIG. 3 is an exploded schematic perspective view of the gas strut assembly.
- FIG. 4 is an enlarged schematic cross sectional view of a detent module of the gas strut assembly showing a resultant force diagram of an opening force of the gas strut assembly generating a first radial force component.
- FIG. 5 is an enlarged schematic cross sectional view of the detent module showing a resultant force diagram of a closing force of the gas strut assembly generating a second radial force component.
- the gas strut assembly 20 includes a housing 22 .
- the housing 22 includes an exterior wall 24 that extends along a central axis 26 .
- the exterior wall 24 includes a circular cross sectional shape perpendicular to the central axis 26 , and defines an interior space 28 , also having a circular cross sectional shape perpendicular to the central axis 26 .
- the housing 22 includes a first open end 30 and a second closed end 32 .
- a rod 34 is coupled to the housing 22 , and extends through the open end of the housing 22 .
- the rod 34 extends along the central axis 26 , and is concentric with the housing 22 about the central axis 26 .
- the rod 34 is slideably moveable within the interior space 28 of the housing 22 along the central axis 26 .
- the rod 34 moves between a retracted or shortened position, shown in FIG. 1 , and an extended or lengthened position, shown in FIG. 2 .
- a sealing pack 36 is attached to the housing 22 , adjacent the first open end 30 of the housing 22 .
- the sealing pack 36 seals between the rod 34 and the housing 22 to trap gas, such as but not limited to air, within the interior space 28 of the housing 22 .
- the sealing pack 36 slideably supports the rod 34 relative to the housing 22 .
- the first open end 30 of the housing 22 is flared radially inward toward the central axis 26 .
- the housing 22 includes a first rim 38 that extends radially inward toward the central axis 26 .
- the first rim 38 is spaced from the flared open end of the housing 22 an axial distance 40 along the central axis 26 equal to a length 42 of the sealing pack 36 measured along the central axis 26 .
- the sealing pack 36 is disposed between the first rim 38 and the flared open end of the housing 22 , and is secured in position relative to the housing 22 by the flared first open end 30 of the housing 22 and the first rim 38 .
- the housing 22 further includes a second rim 44 spaced along the central axis 26 from the first rim 38 .
- a flexible member 46 of an internal detent module 48 (described in greater detail below) is disposed between the sealing pack 36 and the second rim 44 . As such, the flexible member 46 of the internal detent module 48 is secured in position relative to the housing 22 by the sealing pack 36 and the second rim 44 .
- the internal detent module 48 interconnects the housing 22 and the rod 34 when the rod 34 is disposed in the extended position to increase a closing force of the gas strut assembly 20 .
- the closing force is the force required to move the rod 34 from the extended position into the retracted position. Accordingly, the internal detent module 48 increase the force required to move the rod 34 from the extended position into the retracted position.
- the internal detent module 48 includes the flexible member 46 and a rigid member 50 .
- the flexible member 46 is secured in position relative to the housing 22 .
- the rigid member 50 is attached to and moveable with the rod 34 .
- the flexible member 46 includes at least one displaceable portion 52 .
- the displaceable portion 52 includes a plurality of displaceable portions 52 radially spaced about the central axis 26 .
- FIG. 3 shows four displaceable portions 52 in the exemplary embodiment. However, it should be appreciated that the total number of displaceable portions 52 may vary from the four shown in the exemplary embodiment. While only one of the displaceable portions 52 is described in detail herein, each of the displaceable portions 52 is identical. As such, the description of the displaceable portion 52 described below is applicable to all of the displaceable portions 52 .
- the flexible member 46 includes an annular base 54 defining a central aperture 56 .
- the rod 34 extends through the central aperture 56 of the annular base 54 .
- the outer periphery of the annular base 54 extends radially outward into abutting engagement with an interior surface 58 of the exterior wall 24 of the housing 22 .
- the displaceable portion 52 extends axially along the central axis 26 from the annular base 54 , with the displaceable portion 52 disposed between the annular base 54 and the sealing pack 36 .
- the displaceable portion 52 includes a first leg portion 60 extending substantially along the central axis 26 , a wall portion 62 extending from the first leg portion 60 and substantially away from the central axis 26 , and a second leg portion 66 extending from the wall portion 62 and substantially along the central axis 26 .
- the rigid member 50 includes a body 68 that defines a central bore 70 .
- the body 68 is disposed about and concentric with the rod 34 such that the rod 34 passes through the central bore 70 .
- the rod 34 includes a ridge 72 that engages the body 68 of the rigid member 50 and prevents the rigid member 50 from moving axially along the rod 34 in a first axial direction 74 beyond the ridge 72 .
- a clip 76 is coupled to a recess 78 in the rod 34 to prevent movement of the rigid member 50 relative to the rod 34 in a second axial direction 80 , i.e., opposite the first axial direction 74 .
- the rigid member 50 is secured in place on the rod 34 between the ridge 72 and the clip 76 .
- the internal detent module 48 may further include a first washer 82 and a second washer 84 disposed at opposite axial ends of the rigid member 50 .
- the body 68 includes detent 86 , which extends radially away from the body 68 and the central axis 26 .
- the detent 86 is disposed at an axial end of the body 68 facing the first open end 30 of the housing 22 .
- the detent 86 includes an annular ring that extends away from the body 68 of the rigid member 50 , and completely encircles the rod 34 .
- the detent 86 need not completely encircle the rod 34 , and that the detent 86 may include multiple detents, with each of the detents spaced about the body 68 of the rigid member 50 .
- the detent 86 includes a first cam surface 88 and a second cam surface 90 .
- the first cam surface 88 and the second cam surface 90 are defined by rounded or chamfered axial edges of the detent 86 .
- the first cam surface 88 is defined by an axial edge of the detent 86 facing the first open end 30 of the housing 22 .
- the second cam surface 90 is defined by an axial edge of the detent 86 facing the second closed end 32 of the housing 22 .
- the first cam surface 88 engages the displaceable portion 52 when moving from the retracted position into the extended position.
- the displaceable portion 52 moves radially away from the central axis 26 in response to a first radial force component F R1 of an opening force F O when engaged by the first cam surface 88 of the rigid member 50 .
- the opening force F O is a force applied to the rod 34 to move the rod 34 from the retracted position into the extended position.
- the opening force F O is applied by compressed gas, such as but not limited to air, trapped between a piston end 92 of the rigid member 50 and the second closed end 32 of the housing 22 . The compressed gas biases against the piston end 92 of the rigid member 50 to urge the rod 34 from the refracted position into the extended position, thereby providing the opening force F O .
- the first leg portion 60 of the displaceable portion 52 includes a radially inner surface 94 that contacts and/or engages the first cam surface 88 of the detent 86 .
- the radial inner surface 94 of the first leg portion 60 is angled relative to the central axis 26 .
- the first cam surface 88 engages the radial inner surface 94 of the first leg portion 60 to define a first engagement angle 96 there between.
- the first axial force component F A1 is directed along or parallel with the central axis 26
- the first radial force component F R1 is directed perpendicularly away from the central axis 26 , and against the displaceable portion 52 .
- the degree of angle of the first engagement angle 96 relative to the central axis 26 determines how much of the opening force F O is directed into the first axial force component F A1 and the first radial force component F R1 respectively.
- a greater value of the first engagement angle 96 directs more of the opening force F O into the first axial force component F A1 than a lesser value of the first engagement angle 96 , thereby decreasing the first radial force component F R1 and requiring a greater opening force F O to move the displaceable portion 52 radially away from the detent 86 and allow the rigid member 50 to move into the extended position.
- the radial inner surface 94 of the first leg portion 60 is preferably oriented relative to the central axis 26 so that the first engagement angle 96 includes a smaller or lesser value so as not to greatly increase the required opening force F O .
- the first engagement angle 96 may vary between the range of 0° and 45°. However, it should be appreciated that the first engagement angle 96 may differ from the values described herein, and may be defined based upon the particular uses of the gas strut assembly 20 .
- the second cam surface 90 engages the displaceable portion 52 when moving from the extended position into the retracted position.
- the displaceable portion 52 moves radially away from the central axis 26 in response to a second radial force component F R2 of the closing force F C when engaged by the second cam surface 90 of the rigid member 50 .
- the wall portion 62 of the displaceable portion 52 extends from an axial end of the first leg portion 60 and radially away from the central axis 26 .
- the wall portion 62 includes an axial end surface 98 that engages and/or contacts the second cam surface 90 of the detent 86 .
- the axial end surface 98 of the wall portion 62 is angled relative to the central axis 26 .
- the second cam surface 90 engages the axial end surface 98 of the wall portion 62 to define a second engagement angle 100 there between relative to the central axis 26 .
- the engagement between the second cam surface 90 and the axial end surface 98 of the wall portion 62 at the second engagement angle 100 relative to the central axis 26 generates a second axial force component F A2 and the second radial force component F R2 .
- the second axial force component F A2 is directed along or parallel with the central axis 26
- the second radial force component F R2 is directed perpendicularly away from the central axis 26 , and against the displaceable portion 52 .
- the degree of angle of the second engagement angle 100 relative to the central axis 26 determines how much of the closing force F C is directed into the second axial force component F A2 and the second radial force component F R2 respectively.
- a greater value of the second engagement angle 100 directs more of the closing force F C into the second radial force component F R2 than a lesser value of the second engagement angle 100 , thereby requiring a greater closing force F C to move the displaceable portion 52 radially away from the detent 86 and allow the rigid member to move into the retracted position.
- the axial end surface 98 of the wall portion 62 is preferably oriented relative to the central axis 26 so that the second engagement angle 100 includes a higher or greater value so as to significantly increase the required closing force F C .
- the second engagement angle 100 may vary between the range of 0° and 45°.
- the second engagement angle 100 may differ from the values described herein, and may be defined based upon the particular uses of the gas strut assembly 20 .
- the second engagement angle 100 is defined to include a higher value than the first engagement angle 96 , it should be appreciated that the second radial force component F R2 is greater than the first radial force component F R1 .
- the second leg portion 66 of the displaceable portion 52 extends from the wall portion 62 , axially along the central axis 26 and away from the first leg portion 60 .
- the second leg portion 66 includes an inner surface 102 that contacts and/or engages a radial outer surface 104 of the detent 86 . Engagement between the radial outer surface 104 of the detent 86 and the inner surface 102 of the second leg portion 66 limits radial movement of the displaceable portion 52 inward toward the central axis 26 when the rod 34 is in the extended position.
- the engagement between the radial outer surface 104 of the detent 86 and the inner surface 102 of the second leg portion 66 ensures proper engagement between the second cam surface 90 and the axial end surface 98 of the wall portion 62 , and prevents the displaceable portion 52 from flexing radially inward toward the body 68 of the rigid member 50 and becoming wedged in place.
- the flexible member 46 may include and be manufactured from a polymer, such as but not limited to nylon or a plastic.
- a polymer such as but not limited to nylon or a plastic.
- the characteristics of the material used to form the flexible member 46 particularly the stiffness or resistance to bending of the material, affects the force required to move the displaceable portion 52 radially away from the body 68 . As such, the specific material chosen for the flexible member 46 is dependent upon the particular use for the strut assembly.
- a band 106 may be disposed radially about and encircle the displaceable portions 52 .
- the band 106 In order for the displaceable portions 52 to flex radial outward away from the detent 86 of the body 68 , the band 106 must expand in circumferential length 42 . Accordingly, the band 106 increases the force required to move the displaceable portions 52 radially outward away from the detent 86 of the body 68 .
- the material characteristics of the material used to form the band 106 particularly the strain resistance or resistance to stretching, affects the force required to stretch or expand the band 106 , and thereby affects the force required to move the displaceable portions 52 radially away from the body 68 .
- the band 106 may include and be manufactured from a material having a resistance to expansion that is variable with temperature.
- the band 106 may include a resistance to expansion that increases with a decrease in temperature. Accordingly, as the temperature decreases, the resistance of the band 106 to expanding, i.e., stretching, increases, thereby increasing the force required to move the displaceable portions 52 radially away from the detent 86 of the rigid member 50 .
- the specific material chosen for the band 106 is dependent upon the amount of resistance the band 106 is required to provide, which is dependent upon the particular use of the gas strut assembly 20 .
- the band 106 may include and be manufactured from, for example, one of a thermoplastic elastomer or a thermoplastic rubber.
Abstract
Description
- The invention generally relates to a gas strut assembly, and more specifically to an internal detent module for increasing a hold-open force of the gas strut assembly.
- Gas strut assemblies include a housing that defines an interior space, with a rod moveably disposed within the interior space. The rod is slideably moveable along a central axis between a retracted position, i.e., a shortened position, and an extended position, i.e., a lengthened position. A piston is disposed at an axial end of the rod within the interior space of the housing. The housing includes a closed end, and includes a volume of gas, such as but not limited to air, trapped within the interior space of the housing, between the piston and the closed end of the housing. Movement of the rod from the extended position into the retracted position compresses the air between the closed end of the housing and the piston, thereby generating a resulting axial force urging the piston and the rod back into the extended position. As such, the rod is continuously biased toward the extended position.
- Because the gas strut assemblies are biased toward the extended position, the gas strut assemblies are often utilized to provide an opening force and/or to provide a hold-open force to door, trunk lid, hood, etc. However, the gas strut assemblies rely on the compressed gas to provide the axial force urging the piston and the rod into the extended position. Changing ambient temperatures change the temperature of the gas, which changes the density of the gas. For example, when the temperature decreases, the density of gas also decreases, which lowers the resulting axial force that urges the rod into the extended position.
- A gas strut assembly is provided. The gas strut assembly includes a housing having a wall that extends along a central axis. The wall defines an interior space. A rod is coupled to the housing. The rod is slideably moveable within the interior space along the central axis between an extended position and a retracted position. A flexible member is secured in position relative to the housing. A rigid member is coupled to and moveable with the rod. The flexible member includes at least one displaceable portion that moves radially away from the central axis in response to a first radial force component of an opening force when engaged by the rigid member moving from the retracted position into the extended position. The displaceable portion moves radially away from the central axis in response to a second radial force component of a closing force when engaged by the rigid member moving from the extended position into the retracted position. The second radial force component is greater than the first radial force component.
- Accordingly, the interaction between the rigid member and the flexible member resists movement of the rod along the central axis. In order to move the rod from the extended position into the retracted position, the interaction between the flexible member and the rigid member must generate the second radial force component from the closing force. The second radial force component must be sufficient to move the displaceable portion away from the rigid member to allow the rigid member to pass thereby and continue into the refracted position. As such, the mechanical interaction between the rigid member and the flexible member increases the force required to move the rod out of the extended position and into the retracted position, thereby increasing the hold-open force of the gas strut assembly.
- In order to move the rod from the retracted position into the extended position, the interaction between the flexible member and the rigid member must generate the first radial force component from the opening force. The first radial force component must be sufficient to move the displaceable portion away from the rigid member to allow the rigid member to pass thereby and continue into the extended position. As such, the mechanical interaction between the rigid member and the flexible member increases the force required to move the rod into the extended position. The interaction between the flexible member and the rigid member is designed so that the first radial force component is significantly less than the second radial force component so that the axial opening force generated from the compressed gas within the housing is able to generate the first radial force component and move the rod into the extended position.
- The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.
-
FIG. 1 is a schematic cross sectional view of a gas strut assembly in an retracted position. -
FIG. 2 is a schematic cross sectional view of the gas strut assembly in an extended position. -
FIG. 3 is an exploded schematic perspective view of the gas strut assembly. -
FIG. 4 is an enlarged schematic cross sectional view of a detent module of the gas strut assembly showing a resultant force diagram of an opening force of the gas strut assembly generating a first radial force component. -
FIG. 5 is an enlarged schematic cross sectional view of the detent module showing a resultant force diagram of a closing force of the gas strut assembly generating a second radial force component. - Those having ordinary skill in the art will recognize that terms such as “above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are used descriptively for the figures, and do not represent limitations on the scope of the invention, as defined by the appended claims.
- Referring to the Figures, wherein like numerals indicate like parts throughout the several views, a gas strut assembly is generally shown at 20. Referring to
FIGS. 1 and 2 , thegas strut assembly 20 includes ahousing 22. Thehousing 22 includes anexterior wall 24 that extends along acentral axis 26. Theexterior wall 24 includes a circular cross sectional shape perpendicular to thecentral axis 26, and defines aninterior space 28, also having a circular cross sectional shape perpendicular to thecentral axis 26. - The
housing 22 includes a firstopen end 30 and a second closed end 32. Arod 34 is coupled to thehousing 22, and extends through the open end of thehousing 22. Therod 34 extends along thecentral axis 26, and is concentric with thehousing 22 about thecentral axis 26. Therod 34 is slideably moveable within theinterior space 28 of thehousing 22 along thecentral axis 26. Therod 34 moves between a retracted or shortened position, shown inFIG. 1 , and an extended or lengthened position, shown inFIG. 2 . - A
sealing pack 36 is attached to thehousing 22, adjacent the firstopen end 30 of thehousing 22. The sealing pack 36 seals between therod 34 and thehousing 22 to trap gas, such as but not limited to air, within theinterior space 28 of thehousing 22. Thesealing pack 36 slideably supports therod 34 relative to thehousing 22. - The first
open end 30 of thehousing 22 is flared radially inward toward thecentral axis 26. Thehousing 22 includes afirst rim 38 that extends radially inward toward thecentral axis 26. Thefirst rim 38 is spaced from the flared open end of thehousing 22 anaxial distance 40 along thecentral axis 26 equal to a length 42 of thesealing pack 36 measured along thecentral axis 26. Thesealing pack 36 is disposed between thefirst rim 38 and the flared open end of thehousing 22, and is secured in position relative to thehousing 22 by the flared firstopen end 30 of thehousing 22 and thefirst rim 38. - The
housing 22 further includes asecond rim 44 spaced along thecentral axis 26 from thefirst rim 38. Aflexible member 46 of an internal detent module 48 (described in greater detail below) is disposed between thesealing pack 36 and thesecond rim 44. As such, theflexible member 46 of theinternal detent module 48 is secured in position relative to thehousing 22 by thesealing pack 36 and thesecond rim 44. - The
internal detent module 48 interconnects thehousing 22 and therod 34 when therod 34 is disposed in the extended position to increase a closing force of thegas strut assembly 20. The closing force is the force required to move therod 34 from the extended position into the retracted position. Accordingly, theinternal detent module 48 increase the force required to move therod 34 from the extended position into the retracted position. - Referring also to
FIG. 3 , theinternal detent module 48 includes theflexible member 46 and arigid member 50. As described above, theflexible member 46 is secured in position relative to thehousing 22. Therigid member 50 is attached to and moveable with therod 34. Theflexible member 46 includes at least onedisplaceable portion 52. As shown, thedisplaceable portion 52 includes a plurality ofdisplaceable portions 52 radially spaced about thecentral axis 26.FIG. 3 shows fourdisplaceable portions 52 in the exemplary embodiment. However, it should be appreciated that the total number ofdisplaceable portions 52 may vary from the four shown in the exemplary embodiment. While only one of thedisplaceable portions 52 is described in detail herein, each of thedisplaceable portions 52 is identical. As such, the description of thedisplaceable portion 52 described below is applicable to all of thedisplaceable portions 52. - The
flexible member 46 includes anannular base 54 defining acentral aperture 56. Therod 34 extends through thecentral aperture 56 of theannular base 54. The outer periphery of theannular base 54 extends radially outward into abutting engagement with aninterior surface 58 of theexterior wall 24 of thehousing 22. Thedisplaceable portion 52 extends axially along thecentral axis 26 from theannular base 54, with thedisplaceable portion 52 disposed between theannular base 54 and the sealingpack 36. Thedisplaceable portion 52 includes a first leg portion 60 extending substantially along thecentral axis 26, a wall portion 62 extending from the first leg portion 60 and substantially away from thecentral axis 26, and asecond leg portion 66 extending from the wall portion 62 and substantially along thecentral axis 26. - The
rigid member 50 includes abody 68 that defines acentral bore 70. Thebody 68 is disposed about and concentric with therod 34 such that therod 34 passes through thecentral bore 70. As shown, therod 34 includes aridge 72 that engages thebody 68 of therigid member 50 and prevents therigid member 50 from moving axially along therod 34 in a firstaxial direction 74 beyond theridge 72. Aclip 76 is coupled to arecess 78 in therod 34 to prevent movement of therigid member 50 relative to therod 34 in a secondaxial direction 80, i.e., opposite the firstaxial direction 74. As such, therigid member 50 is secured in place on therod 34 between theridge 72 and theclip 76. Theinternal detent module 48 may further include afirst washer 82 and asecond washer 84 disposed at opposite axial ends of therigid member 50. Thebody 68 includesdetent 86, which extends radially away from thebody 68 and thecentral axis 26. Thedetent 86 is disposed at an axial end of thebody 68 facing the firstopen end 30 of thehousing 22. As shown, thedetent 86 includes an annular ring that extends away from thebody 68 of therigid member 50, and completely encircles therod 34. However, it should be appreciated that thedetent 86 need not completely encircle therod 34, and that thedetent 86 may include multiple detents, with each of the detents spaced about thebody 68 of therigid member 50. - The
detent 86 includes afirst cam surface 88 and a second cam surface 90. As shown, thefirst cam surface 88 and the second cam surface 90 are defined by rounded or chamfered axial edges of thedetent 86. Thefirst cam surface 88 is defined by an axial edge of thedetent 86 facing the firstopen end 30 of thehousing 22. The second cam surface 90 is defined by an axial edge of thedetent 86 facing the second closed end 32 of thehousing 22. - Referring to
FIG. 4 , thefirst cam surface 88 engages thedisplaceable portion 52 when moving from the retracted position into the extended position. Thedisplaceable portion 52 moves radially away from thecentral axis 26 in response to a first radial force component FR1 of an opening force FO when engaged by thefirst cam surface 88 of therigid member 50. The opening force FO is a force applied to therod 34 to move therod 34 from the retracted position into the extended position. The opening force FO is applied by compressed gas, such as but not limited to air, trapped between apiston end 92 of therigid member 50 and the second closed end 32 of thehousing 22. The compressed gas biases against thepiston end 92 of therigid member 50 to urge therod 34 from the refracted position into the extended position, thereby providing the opening force FO. - The first leg portion 60 of the
displaceable portion 52 includes a radiallyinner surface 94 that contacts and/or engages thefirst cam surface 88 of thedetent 86. The radialinner surface 94 of the first leg portion 60 is angled relative to thecentral axis 26. Thefirst cam surface 88 engages the radialinner surface 94 of the first leg portion 60 to define afirst engagement angle 96 there between. When the opening force FO is applied to therod 34, the engagement or interaction between thefirst cam surface 88 and the radialinner surface 94 of the first leg portion 60 at thefirst engagement angle 96 relative to thecentral axis 26 generates a first axial force component FA1 and the first radial force component FR1. The first axial force component FA1 is directed along or parallel with thecentral axis 26, and the first radial force component FR1 is directed perpendicularly away from thecentral axis 26, and against thedisplaceable portion 52. The degree of angle of thefirst engagement angle 96 relative to thecentral axis 26 determines how much of the opening force FO is directed into the first axial force component FA1 and the first radial force component FR1 respectively. A greater value of thefirst engagement angle 96 directs more of the opening force FO into the first axial force component FA1 than a lesser value of thefirst engagement angle 96, thereby decreasing the first radial force component FR1 and requiring a greater opening force FO to move thedisplaceable portion 52 radially away from thedetent 86 and allow therigid member 50 to move into the extended position. The radialinner surface 94 of the first leg portion 60 is preferably oriented relative to thecentral axis 26 so that thefirst engagement angle 96 includes a smaller or lesser value so as not to greatly increase the required opening force FO. For example, thefirst engagement angle 96 may vary between the range of 0° and 45°. However, it should be appreciated that thefirst engagement angle 96 may differ from the values described herein, and may be defined based upon the particular uses of thegas strut assembly 20. - Referring to
FIG. 5 , the second cam surface 90 engages thedisplaceable portion 52 when moving from the extended position into the retracted position. Thedisplaceable portion 52 moves radially away from thecentral axis 26 in response to a second radial force component FR2 of the closing force FC when engaged by the second cam surface 90 of therigid member 50. - The wall portion 62 of the
displaceable portion 52 extends from an axial end of the first leg portion 60 and radially away from thecentral axis 26. The wall portion 62 includes anaxial end surface 98 that engages and/or contacts the second cam surface 90 of thedetent 86. Theaxial end surface 98 of the wall portion 62 is angled relative to thecentral axis 26. The second cam surface 90 engages theaxial end surface 98 of the wall portion 62 to define a second engagement angle 100 there between relative to thecentral axis 26. When the closing force FC is applied to therod 34, the engagement between the second cam surface 90 and theaxial end surface 98 of the wall portion 62 at the second engagement angle 100 relative to thecentral axis 26 generates a second axial force component FA2 and the second radial force component FR2. The second axial force component FA2 is directed along or parallel with thecentral axis 26, and the second radial force component FR2 is directed perpendicularly away from thecentral axis 26, and against thedisplaceable portion 52. The degree of angle of the second engagement angle 100 relative to thecentral axis 26 determines how much of the closing force FC is directed into the second axial force component FA2 and the second radial force component FR2 respectively. A greater value of the second engagement angle 100 directs more of the closing force FC into the second radial force component FR2 than a lesser value of the second engagement angle 100, thereby requiring a greater closing force FC to move thedisplaceable portion 52 radially away from thedetent 86 and allow the rigid member to move into the retracted position. Theaxial end surface 98 of the wall portion 62 is preferably oriented relative to thecentral axis 26 so that the second engagement angle 100 includes a higher or greater value so as to significantly increase the required closing force FC. For example, the second engagement angle 100 may vary between the range of 0° and 45°. However, it should be appreciated that the second engagement angle 100 may differ from the values described herein, and may be defined based upon the particular uses of thegas strut assembly 20. When the second engagement angle 100 is defined to include a higher value than thefirst engagement angle 96, it should be appreciated that the second radial force component FR2 is greater than the first radial force component FR1. - The
second leg portion 66 of thedisplaceable portion 52 extends from the wall portion 62, axially along thecentral axis 26 and away from the first leg portion 60. Thesecond leg portion 66 includes aninner surface 102 that contacts and/or engages a radialouter surface 104 of thedetent 86. Engagement between the radialouter surface 104 of thedetent 86 and theinner surface 102 of thesecond leg portion 66 limits radial movement of thedisplaceable portion 52 inward toward thecentral axis 26 when therod 34 is in the extended position. As such, when therod 34 is in the extended position, the engagement between the radialouter surface 104 of thedetent 86 and theinner surface 102 of thesecond leg portion 66 ensures proper engagement between the second cam surface 90 and theaxial end surface 98 of the wall portion 62, and prevents thedisplaceable portion 52 from flexing radially inward toward thebody 68 of therigid member 50 and becoming wedged in place. - The
flexible member 46 may include and be manufactured from a polymer, such as but not limited to nylon or a plastic. The characteristics of the material used to form theflexible member 46, particularly the stiffness or resistance to bending of the material, affects the force required to move thedisplaceable portion 52 radially away from thebody 68. As such, the specific material chosen for theflexible member 46 is dependent upon the particular use for the strut assembly. - A band 106 may be disposed radially about and encircle the
displaceable portions 52. In order for thedisplaceable portions 52 to flex radial outward away from thedetent 86 of thebody 68, the band 106 must expand in circumferential length 42. Accordingly, the band 106 increases the force required to move thedisplaceable portions 52 radially outward away from thedetent 86 of thebody 68. The material characteristics of the material used to form the band 106, particularly the strain resistance or resistance to stretching, affects the force required to stretch or expand the band 106, and thereby affects the force required to move thedisplaceable portions 52 radially away from thebody 68. - The band 106 may include and be manufactured from a material having a resistance to expansion that is variable with temperature. As such, the band 106 may include a resistance to expansion that increases with a decrease in temperature. Accordingly, as the temperature decreases, the resistance of the band 106 to expanding, i.e., stretching, increases, thereby increasing the force required to move the
displaceable portions 52 radially away from thedetent 86 of therigid member 50. As such, the specific material chosen for the band 106 is dependent upon the amount of resistance the band 106 is required to provide, which is dependent upon the particular use of thegas strut assembly 20. However, the band 106 may include and be manufactured from, for example, one of a thermoplastic elastomer or a thermoplastic rubber. - The detailed description and the drawings or figures are supportive and descriptive of the invention, but the scope of the invention is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed invention have been described in detail, various alternative designs and embodiments exist for practicing the invention defined in the appended claims.
Claims (20)
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/473,906 US20130305915A1 (en) | 2012-05-17 | 2012-05-17 | Gas strut assembly with an internal detent module |
DE102013208508A DE102013208508A1 (en) | 2012-05-17 | 2013-05-08 | Gas strut assembly with inner locking module |
CN2013101834595A CN103423262A (en) | 2012-05-17 | 2013-05-17 | Gas strut assembly with an internal detent module |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/473,906 US20130305915A1 (en) | 2012-05-17 | 2012-05-17 | Gas strut assembly with an internal detent module |
Publications (1)
Publication Number | Publication Date |
---|---|
US20130305915A1 true US20130305915A1 (en) | 2013-11-21 |
Family
ID=49511127
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/473,906 Abandoned US20130305915A1 (en) | 2012-05-17 | 2012-05-17 | Gas strut assembly with an internal detent module |
Country Status (3)
Country | Link |
---|---|
US (1) | US20130305915A1 (en) |
CN (1) | CN103423262A (en) |
DE (1) | DE102013208508A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
ES2770062T3 (en) * | 2017-09-05 | 2020-06-30 | Safran Landing Systems Uk Ltd | Telescopic device |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5540138A (en) * | 1993-09-02 | 1996-07-30 | Robbins, Jr. ; Roland W. | Lockup and release device |
US20070014630A1 (en) * | 2005-03-14 | 2007-01-18 | Brown David A | Shrinkage-compensating continuity system |
US20070233255A1 (en) * | 2006-03-06 | 2007-10-04 | Vermillion Technologies, Llc | Intervertebral disc replacement prosthesis |
US7410038B2 (en) * | 2002-10-11 | 2008-08-12 | Svm Schultz Verwaltungs-Gmbh & Co. Kg | Locking unit |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CH608282A5 (en) * | 1975-05-23 | 1978-12-29 | Allinquant F M | |
FR2719641B1 (en) * | 1994-05-06 | 1996-07-26 | Peugeot | Gas spring holding an articulated wall of a motor vehicle with adjustable opening. |
JPH10252801A (en) * | 1997-01-07 | 1998-09-22 | Showa:Kk | Gas spring |
US8246019B2 (en) * | 2007-06-21 | 2012-08-21 | GM Global Technology Operations LLC | Air spring for vehicle closure |
-
2012
- 2012-05-17 US US13/473,906 patent/US20130305915A1/en not_active Abandoned
-
2013
- 2013-05-08 DE DE102013208508A patent/DE102013208508A1/en not_active Ceased
- 2013-05-17 CN CN2013101834595A patent/CN103423262A/en active Pending
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5540138A (en) * | 1993-09-02 | 1996-07-30 | Robbins, Jr. ; Roland W. | Lockup and release device |
US7410038B2 (en) * | 2002-10-11 | 2008-08-12 | Svm Schultz Verwaltungs-Gmbh & Co. Kg | Locking unit |
US20070014630A1 (en) * | 2005-03-14 | 2007-01-18 | Brown David A | Shrinkage-compensating continuity system |
US20070233255A1 (en) * | 2006-03-06 | 2007-10-04 | Vermillion Technologies, Llc | Intervertebral disc replacement prosthesis |
Also Published As
Publication number | Publication date |
---|---|
DE102013208508A1 (en) | 2013-11-21 |
CN103423262A (en) | 2013-12-04 |
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