Title:
Retractable suspension
Kind Code:
A1


Abstract:
A wheeled transport device that includes a body, a handle coupled to the body, a suspension system coupled to the body, and at least one wheel rotatably secured to the suspension system. The suspension system is retracted toward the body when the handle is moved from an extended position to a retracted position.



Inventors:
Dayton, Douglas C. (Harvard, MA, US)
Application Number:
12/504328
Publication Date:
02/04/2010
Filing Date:
07/16/2009
Primary Class:
Other Classes:
280/124.1, 190/115
International Classes:
A45C5/14; A45C13/28
View Patent Images:



Primary Examiner:
MAI, TRI M
Attorney, Agent or Firm:
FISH & RICHARDSON P.C. (BO) (MINNEAPOLIS, MN, US)
Claims:
What is claimed is:

1. A wheeled transport device, comprising: a body; a handle coupled to the body, the handle being movable between an extended position and a retracted position; a suspension system coupled to the body; at least one wheel rotatably secured to the suspension system; and a cam arranged to retract the suspension system toward the body when the handle is moved from the extended position to the retracted position.

2. The wheeled transport device of claim 1, wherein the wheeled transport device is a wheeled luggage device.

3. The wheeled transport device of claim 1, wherein the handle and the cam are arranged so that the handle rotates the cam when the handle is moved to the retracted position.

4. The wheeled transport device of claim 1, wherein the handle defines a recess configured to receive the cam when the handle is in the retracted position.

5. The wheeled transport device of claim 4, wherein the recess is configured to substantially prevent the cam from rotating when the handle is in the retracted position.

6. The wheeled transport device of claim 5, wherein the cam is configured to substantially prevent the suspension system from rotating when the handle is in the retracted position.

7. The wheeled transport device of claim 1, wherein the handle comprises a projection configured to contact the cam when the handle is moved to the retracted position.

8. The wheeled transport device of claim 1, wherein the cam is arranged so that the cam contacts a member of the suspension system when the handle is moved to the retracted position.

9. The wheeled transport device of claim 1, wherein the cam is spring loaded.

10. The wheeled transport device of claim 1, wherein the suspension system is spring loaded so that the suspension system is deployed away from the body when the handle is in the extended position.

11. The wheeled transport device of claim 10, wherein a rolling surface of the wheel is extended beyond the body when the handle is in the extended position.

12. The wheeled transport device of claim 1, wherein the cam comprises a projection disposed in a slot defined by the suspension system.

13. The wheeled transport device of claim 12, wherein the slot comprises a first segment and a second segment that extends at an obtuse angle relative to the first segment.

14. The wheeled transport device of claim 13, wherein the projection is disposed in the first segment of the slot when the handle is in the retracted position and the projection is disposed in the second segment of the slot when the handle is in the extended position.

15. The wheeled transport device of claim 1, wherein the suspension system comprises a first member and a second member that is rotatable relative to the first member, the wheel being coupled to the second member.

16. The wheeled transport device of claim 15, wherein the first member is fixed to the body.

17. The wheeled transport device of claim 15, wherein the suspension system further comprises a spring-damper disposed between the first and second members, the spring-damper configured to resist rotation of the second member relative to the first member.

18. The wheeled transport device of claim 1, wherein an entire area of the wheel overlays an area defined by the body when the handle is in the retracted position.

19. A wheeled transport device configured to be manually wheeled in an inclined position by a pedestrian user, the transport device comprising: a body; a handle coupled to the body, the handle being movable between an extended position and a retracted position, and, when in the extended position, the handle being manually graspable by the pedestrian user while walking; at least one wheel disposed at a lower end portion of the body when the transport device is in an operative, inclined position; and a suspension device coupling at least one wheel to the body; and a cam coupled to the suspension device, the cam being arranged to retract the suspension system and the wheel toward the body when the handle is moved from an extended position to a retracted position.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Application Ser. No. 61/085,633, filed on Aug. 1, 2008, which is incorporated by reference herein.

TECHNICAL FIELD

This invention relates to retractable suspensions.

BACKGROUND

Wheeled transport devices are commonly used to transport goods from one location to another. One example of a wheeled transport device is a luggage device. Luggage devices can include wheels for making transport of the luggage easier for the user. Luggage devices commonly include wheels along a base of the device and a handle extending from the upper portion of the device to allow the user to tote the luggage by grasping the handle and wheeling the luggage along a surface.

SUMMARY

In one aspect of the invention, a wheeled transport device includes a body, a handle coupled to the body, a suspension system coupled to the body, at least one wheel rotatably secured to the suspension system, and a cam arranged to retract the suspension system toward the body when the handle is moved from an extended position to a retracted position.

In another aspect of the invention, a wheeled transport device configured to be manually wheeled in an inclined position by a pedestrian user includes a body, a handle coupled to the body, at least one wheel disposed at a lower end portion of the body when the transport device is in an operative, inclined position, a suspension device coupling at least one wheel to the body, and a cam coupled to the suspension device. The handle is movable between an extended position and a retracted position, and, when in the extended position, the handle is manually graspable by the pedestrian user while walking. The cam is arranged to retract the suspension system and the wheel toward the body when the handle is moved from an extended position to a retracted position.

Embodiments can include one or more of the following features.

In some embodiments, the wheeled transport device is a wheeled luggage device.

In certain embodiments, the handle and the cam are arranged so that the handle rotates the cam when the handle is moved to the retracted position.

In some embodiments, the handle defines a recess configured to receive the cam when the handle is in the retracted position.

In certain embodiments, the recess is configured to substantially prevent the cam from rotating when the handle is in the retracted position.

In some embodiments, the cam is configured to substantially prevent the suspension system from rotating when the handle is in the retracted position.

In certain embodiments, the handle includes a projection configured to contact the cam when the handle is moved to the retracted position.

In some embodiments, the cam is arranged so that the cam contacts a member of the suspension system when the handle is moved to the retracted position.

In certain embodiments, the cam is spring loaded.

In some embodiments, the suspension system is spring loaded so that the suspension system is deployed away from the body when the handle is in the extended position.

In certain embodiments, a rolling surface of the wheel is extended beyond the body when the handle is in the extended position.

In some embodiments, the cam includes a projection disposed in a slot defined by the suspension system.

In certain embodiments, the slot includes a first segment that extends at an obtuse angle relative to a second segment.

In some embodiments, the projection is disposed in the first segment of the slot when the handle is in the retracted position and the projection is disposed in the second segment of the slot when the handle is in the extended position.

In certain embodiments, the suspension system includes a first member and a second member that is rotatable relative to the first member, the wheel being coupled to the second member.

In some embodiments, the first member is fixed to the body.

In certain embodiments, the suspension system further includes a spring-damper disposed between the first and second members, the spring-damper configured to resist rotation of the second member relative to the first member.

In some embodiments, an entire area of the wheel overlays an area defined by the body when the handle is in the retracted position.

Embodiments can include one or more of the following advantages.

In certain embodiments, the suspension system and the wheel attached to the suspension system can be retracted such that the outer surface of the wheel is substantially flush with a surface (e.g., a bottom surface) of the body of the wheeled transport device. In this retracted position, the wheeled transport device occupies less space and the wheel and suspension system are less likely to be damaged.

In certain embodiments, the entire suspension system is retracted upon pushing the handle in to its retracted position. With this arrangement, the wheel, which is secured to the suspension system, can be retracted without having to overcome the spring force provided by the suspension system (e.g., a spring-damper of the suspension system). As a result, this arrangement can help to reduce the amount of force required to retract the wheel.

Other aspects, features, and advantages are in the description, drawings, and claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a wheeled luggage device with retractable suspension systems.

FIG. 2A illustrates a user rolling the wheeled luggage device of FIG. 1 along a surface.

FIG. 2B illustrates a user retracting the suspension systems and wheels of the wheeled luggage device of FIG. 1 by pushing a handle of the wheeled luggage device into a retracted position.

FIG. 2C illustrates a user stowing the wheeled luggage device of FIG. 1 with the suspension systems and wheels in a retracted position.

FIG. 3 is an exploded view of a portion of the wheeled luggage device of FIG. 1 including a retractable suspension system.

FIGS. 4A-4C illustrate the suspension systems and wheels of the wheeled luggage device of FIG. 1 being deployed by pulling a handle of the wheeled luggage device into an extended position.

FIGS. 5A-5C illustrate the suspension systems and wheels of the wheeled luggage device of FIG. 1 being retracted by pushing the handle of the wheeled luggage device into a retracted position.

FIG. 6 is an exploded view of an alternative arrangement of components that allow a suspension system and wheel of a wheeled luggage device to be deployed and retracted.

FIGS. 7A and 7B illustrate a method of deploying the suspension system and wheel of a wheeled luggage device equipped with the components of FIG. 6 by pulling a handle of the wheeled luggage device into an extended position.

FIGS. 8A-8C illustrate a method of retracting the suspension device and wheels of a wheeled luggage device equipped with the components of FIG. 6 by pushing the handle of the wheeled luggage device into an extended position.

DETAILED DESCRIPTION

As shown in FIG. 1, a wheeled luggage device 100 includes a body 102, a handle 104 that can be received in and extended from the body 102, wheels 106, 108, and suspension systems 110, 112 that couple wheels 106 and 108, respectively, to the body 102. Wheels 106, 108 and suspensions systems 110, 112 extend from body 102 when handle 104 is pulled into an extended position (i.e., pulled away from body 102), and wheels 106, 108 and suspensions systems 110, 112 are retracted toward body 102 when handle 104 is pushed into a retracted position (i.e., pushed into body 102). Wheels 106, 108 extend beyond the outer perimeter of body 102 when in the extended position and are fully within the boundary of body 102 when in the retracted position. While we focus on wheel 106 and suspension system 110 in certain portions of the discussion below, it will be appreciated that wheel 108 and suspension system 112 can be substantially identical to wheel 106 and suspension system 110.

Retractable suspension systems 110, 112 provide benefits both during transport of luggage device 100 and when storing luggage device 100. FIG. 2A illustrates a user grasping the extended handle 104 of luggage device 100 and rolling luggage device 100 along a rough surface. As shown in FIG. 2A, wheel 106 is mounted on suspension system 100, which includes a spring-damper 116. As luggage device 100 is wheeled over the rough surface, a component of suspension system 100 on which wheel 106 is mounted is allowed to rotate relative to another component of suspension system 100 that is secured to body 102 of luggage device 100. As these components of suspension system 110 rotate relative to one another, spring-damper 116 dissipates energy imparted to wheel 106 by the rough surface. This can help to promote stability of luggage device 100, reduce discomfort experienced by the user, and/or reduce damage to luggage device 100.

FIG. 2B illustrates the user pushing handle 104 into body 102 to retract wheel 106 and suspension system 110 from a deployed position (shown in dashed lines) to a retracted position. As shown in FIG. 2B, pushing handle 104 into body 102 so that it lies flush with the top surface of luggage device 100 causes suspension system 110 and wheel 106 to rotate inward thus bringing the outer surface of wheel 106 flush to the bottom surface of luggage device 100.

FIG. 2C illustrates the user stowing luggage device 100 (with handle 104, wheel 106, and suspension system 110 in the retracted position) in an overhead compartment 118. The retracted wheel 106 is flush with body 102 of luggage device 100 creating a monolithic shape that will not readily catch on the mechanisms or geometry of compartment 118 while luggage device 100 is being stowed.

With handle 104, wheels 106, 108, and suspension systems 110, 112 in the retracted position, luggage device 100 occupies less space. In this configuration, luggage device 100 is also generally less likely to suffer damage. For example, when wheels 106, 108 and suspension systems 110, 112 of luggage device 100 are in the retracted position, they are less likely to catch on an object and become damaged. Further, by retracting wheels 106, 108 and suspension systems 110, 112 such that they entirely overlap body 102 (e.g., such that they do not extend beyond the lower edge or rear edge of body 102), impacts caused by dropping luggage device 100 or otherwise handling luggage device 100 roughly will typically be absorbed by the durable luggage body 102 as opposed to wheels 106, 108 and suspension systems 110, 112.

FIG. 3 is an exploded view of a lower portion of the luggage device, which includes suspension system 110. As shown in FIG. 3, suspension system 110 includes a rigid suspension sub-frame 120 to which a suspension plate 122 is rotatably secured. Suspension plate 122 defines an aperture 124 that receives an axle 126 extending from suspension sub-frame 120, thereby allowing suspension plate 122 to rotate about axle 126. Suspension plate 122 has a platform 128 to accommodate a lower mounting point of spring-damper 116. Suspension sub-frame 120 similarly includes a platform 130 that engages an opposite end of spring-damper 116. Suspension sub-frame 120 is rotatably secured to a mounting plate 132 that is rigidly affixed to the sidewall of body 102 of luggage device 100. In particular, a portion of axle 126 extending from the far side of suspension sub-frame 120 extends into an aperture 133 formed in mounting plate 132, allowing suspension sub-frame 120 to rotate relative to mounting plate 132 about the longitudinal axis of axle 126. A torsion spring 134 is fixed to both mounting plate 132 and suspension sub-frame 120 and is arranged to bias the left end portion of suspension sub-frame 120 away from mounting plate 132 (i.e., downward in the view of FIG. 3).

Wheel 106, which supports and allows rolling transport of luggage device 100, is rotatably coupled to an axle 136 extending from suspension plate 122. Wheel 106 moves against spring-damper 116 when wheel 106 encounters impact loads as the luggage is being pulled. The compression of spring-damper 116 softens the impact transmitted to the luggage body and dissipates the energy. A substantial amount of wheel impact motion is confined within the suspension sub-frame 120, as will be described below.

A locking cam 138 is rotatably coupled to the right end portion of suspension sub-frame 120. In particular, locking cam 138 defines an aperture 140 that receives an axle 142 extending from suspension sub-frame 120. A torsion spring 144 is fixed to both suspension sub-frame 120 and locking cam 138 and is arranged to bias the left end portion of locking cam 138 away from suspension sub-frame 120 (i.e., downward in the view of FIG. 3). Suspension sub-frame 120 can be held fixed in the deployed or retracted position by locking cam 138 and handle 104. In particular, locking cam 138 can cooperate with handle 104 to inhibit (e.g., prevent) rotation of suspension sub-frame 120 from either chosen position. The bottom region of handle 104 is bifurcated to form a push bar 146 and a lock-closed ramp 148. Pushing in on handle 104 engages push bar 146 and lock-closed ramp 148 with locking cam 138. As discussed below, a cam support block 150, which is rigidly fixed to mounting plate 132, cooperates with locking cam 138 to help maintain suspension sub-frame 120 in the deployed position or retracted position, depending on the position of handle 104.

FIGS. 4A-4C illustrate a method of deploying suspension system 110 and wheel 106 of wheeled luggage device 100 by pulling handle 104 away from body 102. As shown in FIG. 4A, with handle 104 in the fully retracted (i.e., pushed in) position, lock-closed ramp 148 of handle 104 is engaged against the top surface of locking cam 138 and push bar 146 is engaged against the bottom surface of locking cam 138. As a result, locking cam 138 is unable to overcome the light force pre-load of torsion spring 144 and is thus inhibited (e.g., prevented) from rotating about axle 142. Rotation of suspension sub-frame 120 is also inhibited (e.g., prevented) due to the inability or reduced ability of locking cam 138 to rotate.

Referring to FIG. 4B, as handle 104 is pulled away from its stored position, push bar 146 and lock-closed ramp 148 disengage from locking cam 138. Because lock-closed ramp 148 no longer contacts the top surface of locking cam 138, torsion spring 134 causes suspension sub-frame 120 to rotate about axle 126 into its deployed position. Additionally, torsion spring 144 of locking cam 138 rotates locking cam 138 into its locking position against cam support block 150. In this locking position, locking cam 138 inhibits (e.g., prevents) suspension sub-frame 120 from rotating in a clockwise direction about axle 126, and thus inhibits (e.g., prevents) suspension sub-frame 120 from retracting back toward body 102 of luggage device 100. In the static state shown in FIG. 4B, the spring of spring-damper 116 is at maximum extension (indicated by arrows 152) while suspension plate 122 is pivoted about axle 126 to its further distance of extension away from body 102 of luggage device 100 (i.e., to its most downward position in the view of FIG. 4B). Mounting plate 132 can include a stop block to inhibit (e.g., prevent) suspension plate 122 (e.g., suspension plate 122 and suspension sub-frame 120) from extending beyond a maximum desired extended position. The stop block can protrude from and be rigidly attached to mounting plate 132 at a location between the top edge of mounting plate 132 (in the view shown in FIG. 4B) and the portion of suspension sub-frame 120 to the right of axle 126 (in the view shown in FIG. 4B). As the portion of suspension sub-frame 120 to the right of axle 126 rotates upward as handle 104 is retracted, suspension sub-frame 120 comes into contact with the stop block and is inhibited or prevented from rotating further upward. At the same time, locking cam 138 inhibits or prevents suspension sub-frame 120 from rotating in the opposite direction. Loads imparted to wheel 106 as luggage device 100 is rolled along a rough surface can be dissipated by spring-damper 116 since wheel 106, suspension plate 122, and spring-damper 116 are the only elements allowed to freely rotate when suspension system 110 is in the deployed position shown in FIG. 4B.

When an impact occurs to wheel 106, suspension system 110 reacts to reduce (e.g., minimize) the impact experienced by body 102 and handle 104 of luggage device 100 and thus reduce (e.g., minimize) the impact experienced by the user holding handle 104. As shown in FIG. 4C, when wheel 106 is rolled over uneven terrain 154, an impact load is imparted to wheel 106, causing suspension plate 122 to rotate upward (indicated by arrow 156) about axle 126. This rotation of suspension plate 122 compresses spring-damper 116 (as indicated by 158). Thus, spring-damper 116 dissipates much of the energy imparted to wheel 106. Residual loads are transmitted through axle 126 and top spring mount 130 on suspension sub-frame 120. These loads are resolved via the pivotal axis mounting of suspension sub-frame 120 into mounting plate 132 and primarily as a compression loading of locking cam 138 resisted by cam support block 150.

FIGS. 5A-5C illustrate a method of retracting suspension system 110 and wheel 106 of wheeled luggage device 100 by pushing handle 104 into body 102. Referring to FIG. 5A, as handle 104 is pushed into body 102 of luggage device 100, push bar 146 at the bottom portion of handle 104 encounters the lower profile of locking cam 138 and rotates locking cam 138 against the light pressure of torsion spring 144 (i.e., in the clockwise direction). This rotation frees suspension sub-frame 120 to rotate in the clockwise direction about axle 126, but torsion spring 134 resists this retracting rotation of suspension sub-frame 120.

Referring to FIG. 5B, continued retraction of suspension system 110 is effected by continued closure of handle 104. As handle 104 is pushed further into body 102, push bar 146 continues to rotate locking cam 138 and lock-closed ramp 148 comes into contact with the top lobe of locking cam 138. The long ramp angle of lock-closed ramp 148 creates downward pressure on the rounded surface of locking cam 138 and thus creates downward pressure on the right end portion of suspension sub-frame 120. That pressure overcomes the resistance of torsion spring 134, thereby rotating suspension sub-frame 120 in a clockwise direction about axle 126.

Referring to FIG. 5C, suspension system 110 returns to its fully retracted position as handle 104 is pushed in to the fully closed position. As handle 104 is pushed into the fully closed position, the force of push bar 146 on the bottom portion of locking cam 138 and the force of lock-closed ramp 148 on the upper portion of locking cam 138 overcome the light force pre-load of torsion spring 144 and rotate locking cam 138 into the fully closed position. As the top lobe of locking cam 138 is forced downward by lock-closed ramp 148, the right end portion of suspension sub-frame 120 to which locking cam 138 is attached is also forced downward (i.e., toward push bar 146). As a result, the left end portion of suspension sub-frame 120, along with suspension plate 122 and wheel 106, is rotated upward into the fully retracted position. In this position, locking cam 138 is securely engaged between lock-closed ramp 148 and push bar 146 of handle 104 such that locking cam 138 is inhibited (e.g., prevented) from rotating about axle 142. As a result, rotation of suspension sub-frame 120 is inhibited (e.g., prevented).

As discussed above, when handle 104 is pushed into body 102 of luggage device 100, the entire assembly of suspension sub-frame 120, spring-damper 116, suspension plate 122, and wheel 106 is caused to rotate in order to retract wheel 106. Thus, it is not necessary to overcome the spring force of spring-damper 116 while retracting wheel 106. Instead, the user only needs to apply sufficient force to overcome the light resistance of torsion springs 134 and 144. As a result, wheel 106 can be retracted with relatively little force.

While luggage device 100 has been described as including the retractable suspension system described above, other types of retractable suspension systems can be used with wheeled luggage devices. FIG. 6, for example, is an exploded view of an alternative suspension system 210 and related components that can be used with a wheeled luggage device. As shown in FIG. 6, suspension system 210 includes a lower suspension frame 222 that is rotatably secured to an upper suspension sub-frame 220. In particular, lower suspension frame 222 defines an aperture 224 that receives an axle 226 extending from upper suspension sub-frame 220. Upper suspension sub-frame 220 is rotatably mounted to a mounting plate 232 via an axle 227 that extends into an aperture 243 formed in mounting plate 232. Mounting plate 232 is rigidly fixed to a sidewall of the luggage device. Lower suspension frame 222 has a platform 228 to accommodate the lower mounting point of spring-damper 216 and upper suspension sub-frame 520 has a platform 230 that engages the opposite end of spring-damper 216. A wheel 206 is rotatably secured to lower suspension frame 222 via an axle 236 extending from lower suspension frame 222. Wheel 206 moves against spring-damper 216 when it encounters impact loads as the luggage device is being rolled along a surface. The compression of spring-damper 216 softens the impact transmitted to the luggage body and dissipates the energy. A substantial amount of wheel impact motion is confined to wheel 206, lower suspension frame 222, and spring/damper 216.

A locking cam 238 is rotatably secured to mounting plate 232. In particular, an axle 240 extending from the surface of locking cam 238 extends into an aperture 242 defined by mounting plate 232. Due to the position of axle 240 on locking cam 238, locking cam 238 has an eccentric rotational axis. A cam actuating pin 244 extends from the opposing end of locking cam 238. Cam actuating pin 244 rides in an arc-shaped track or slot 245 defined by upper suspension sub-frame 220. The lower profile of locking cam 23 8 is substantially u-shaped such that the lower portion of locking cam 23 8 forms first and second arms 239, 241.

The bottom portion of a handle 204 of the luggage device includes an actuating pin 246 that extends laterally therefrom. When handle 204 is pushed into the body of the luggage device and pulled away from the body of the luggage device, actuating pin engages first and second arms 239, 241, respectively, of locking cam 238. Contact between actuating pin 246 and arms 239, 241 of locking cam 238 cause locking cam 238 to rotate about axle 240. This rotational motion of locking cam 23 8 effects a rotational motion in upper suspension sub-frame 220 as actuating pin 244 of locking cam 238 provides a torque as a result of the resolution of forces within track 245 of upper suspension sub-frame 220. As discussed below, the rotation of upper suspension sub-frame 220 can cause the entire assembly of upper suspension sub-frame 220, lower suspension frame 222, wheel 206, and spring-damper 216 to rotate, and thus deploy or retract wheel 206.

FIGS. 7A and 7B illustrate a method of deploying wheel 206 of the luggage device. As shown in FIG. 7A, when handle 204 is pushed fully into the luggage device, actuating pin 246 of handle 204 is in contact with first arm 239 of locking cam 238, and thus inhibits (e.g., prevents) locking cam 238 from rotating in a counterclockwise direction. In this configuration, wheel 206 and suspension system 210 are retracted such that locking cam actuating pin 244 resides within the upper right portion of track (as viewed in FIG. 7A) in upper suspension sub-frame 220.

Referring to FIG. 7B, as handle 204 is pulled away from the body of the luggage device, actuating pin 246 of handle 204 contacts second arm 241 of locking cam 238, causing locking cam 238 to rotate in a counterclockwise direction about axle 240. This counterclockwise rotation of locking cam 238 causes locking cam actuating pin 244 to apply an upward force to the portion of upper suspension sub-frame 220 that defines track 245, causing upper suspension sub-frame 220 to similarly rotate in a counterclockwise direction about axle 227. This motion begins to deploy wheel 206 away from the body of the luggage device. As locking cam 238 continues to rotate in a counterclockwise direction, locking cam actuating pin 244 slides from the upper right portion of track 245 to the lower left portion of track 245 and wheel 206 is fully deployed. With locking cam actuating pin 244 positioned in the lower left portion of track 245, as shown in FIG. 7B, wheel 206 remains locked in the fully deployed position. For example, as forces are applied to the portion of wheel 206 that rolls along the ground during use (i.e., the lower left portion of wheel 206 in the view of FIG. 7B) those forces are generally absorbed by spring-damper 216. Some amount of residual force may be applied to axle 227 of upper suspension sub-frame 220, but that force will not substantially affect the position of upper suspension sub-frame 220 relative to locking cam actuating pin 244 because axle 227 is fixed to mounting plate 232. In addition, due to the geometry of track 245, rotational forces applied to upper suspension sub-frame 220 will not generally cause upper suspension sub-frame 220 to move relative to locking cam actuating pin 244. Track 245 can, for example, include a locking segment that extends at an angle (e.g., an obtuse angle) relative to the main segment of track 245. The locking segment is arranged so that a substantially normal (i.e., substantially 90 degree) force is experienced between locking cam actuating pin 244 and the portion of suspension sub-frame 120 that defines the locking segment of track 245 when suspension sub-frame 220 rotates about axle 227. Such rotation can, for example, occur as a result of wheel 206 impacting a rough portion of the ground surface when the luggage device is being pulled or pushed by the user.

FIGS. 8A-8C illustrate a method of retracting wheel 206 of the luggage device. As shown in FIG. 8A, as handle 206 is pushed into the body of the luggage device, actuating pin 246 of handle 206 contacts first arm 239 of locking cam 238 and begins to rotate locking cam 238 in a clockwise direction. As a result of this motion, locking cam actuating pin 244 places a downward force on the portion of upper suspension sub-frame 220 that defines track 245, causing upper suspension sub-frame 220 to similarly rotate in a clockwise direction. This causes lower suspension frame 222, spring-damper 216, and wheel 206 to rotate in a clockwise direction, and thus retracts wheel 206 toward the body of the luggage device. Because the entire assembly of upper suspension sub-frame 220, lower suspension frame 222, spring-damper 216, and wheel 206 are rotated to retract wheel 206, it is unnecessary to overcome the spring force supplied by spring-damper 216 in order to retract wheel 206. Thus, wheel 206 can be retracted with a relatively small amount force applied to handle 204.

Referring to FIG. 8B, with continued pushing of handle 204 and rotation of locking cam 238, locking cam actuating pin 244 continues to apply a downward force to the portion of upper suspension sub-frame 220 that defines track 245 and thus slides from the lower left portion of track 245 toward the upper right portion of track 245. As a result of this motion, wheel 206 is further retracted toward the body of the luggage device.

As shown in FIG. 8C, when handle 204 is fully pushed into the body of the luggage device, locking cam actuating pin 244 rests within the upper right portion of track 245 and wheel 206 is fully retracted into the body of the luggage device. In this position, actuating pin 246 of handle 204 contacts first arm 239 of locking cam 238 and thus inhibits (e.g., prevents) locking cam 238 from rotating in a counterclockwise direction. As a result, wheel 206 and suspension system 210 are inhibited (e.g., prevented) from rotating away from the body of the luggage device into the deployed position.

While certain embodiments have been described above, other embodiments are possible.

While certain components have been described as being attached to or integrally formed with a mounting plate, which is affixed to the sidewall of the body of the luggage device, those components can alternatively be attached to or formed integrally with the sidewall of the body of the luggage device.

While the suspension systems above are described as including a spring-damper, any of various other force absorption devices can alternatively or additionally be used.

While the retractable suspension systems described above have been described as being installed in wheeled luggage devices, the suspension systems can alternatively or additionally be used with any of various other types of wheeled transport devices.

Other embodiments are in the claims.