WO2004088163A2

WO2004088163A2 - Shock absorbing suspension wheel housing for luggage

Info

Publication number: WO2004088163A2
Application number: PCT/US2004/008900
Authority: WO
Inventors: Philip J. Karl
Original assignee: Samsonite Corporation
Priority date: 2003-03-25
Filing date: 2004-03-24
Publication date: 2004-10-14
Also published as: WO2004088163A3

Abstract

Upright cases typically include a pair of wheels mounted at corners of the lower forward edge of the packing case portion for permitting the luggage case to be wheeled across the horizontal surface. The wheel assembly disclosed includes an elongated lever (14) mounted at its upper end (16) of the luggage case by an axle (22). The lever supports a wheel (12) at its lower end. The lever protrudes from the frontmost portion of the wheel assembly so that the lever itself can engage and absorb the impact of a barrier or obstacle such as a curb or stair step when the case is pulled over the obstacle, as well as help isolate the luggage case and the user's hand from vibration when the case is wheeled over a bumpy floor.

Description

SHOCK ABSORBING SUSPENSION WHEEL HOUSING FOR LUGGAGE

Background of the Invention

This invention relates to molded parts for wheeled luggage cases, specifically

wheels and mounting systems for wheels normally attached at lower corners of the

packing container portions of upright wheeled luggage cases. This packing container

usually has a handle for towing the luggage case supported on these corner mounted

wheels. More specifically, this invention relates to resilient mounting schemes to help

cushion the luggage case and, more specifically, to help cushion the user's hand

supporting the extendable handle of the luggage case from vibrations while the luggage case is being wheeled over a bumpy floor surface such as brick, tile, cobblestone, and

the like. A problem with some luggage cases when they are wheeled in the manner

described above is that the noise and vibration can be transmitted through and

sometimes amplified by the packing container and by the extendable handle. This noise and vibration can contribute to the fatigue experienced by the user, especially if the

luggage case is towed over long distances. Also, the contents of the case can be

adversely affected by this transmitted vibration. Clothes may become more compacted

and thus more wrinkled than they would if this vibration did not occur. If a delicate

, apparatus, such as a laptop computer, is being carried in the case, this vibration could

be transmitted to delicate portions of the laptop computer. Also, it is expected that the

user would drag the wheeled luggage case up curbs and over door thresholds. The user

usually rolls the luggage case up to the curb and impacts the curb at a slow walking

speed. The vibrations from such impact can also be transmitted to the user as well as the case and its contents.

Brief Summary of the Invention

Accordingly, it is an object of the invention to provide a wheel mounted to the

packing case portion of an upright case on a pivotal fork-like mounting lever. This

mounting lever is pivotally attached to the luggage case, preferably through an attached

housing. Between the pivotal mounting lever and the case or housing is a space that

permits this lever to rotate about its pivotal attachment. A spring, preferably a leaf spring, is positioned in this space and is loosely affixed to one or the other of the

housing and the pivotal support lever. Impact on the wheel and impact on the pivotal

support lever tends to compress this spring, permitting the support lever to move in

response to impact forces toward the mounting housing. The mounting lever has a surface that protrudes toward and is exposed to projections (curb and stair step edges)

that the user might impact when wheeling the case forward over curbs and the like.

Brief Description of the Drawings

Figure 1 is a perspective view of the upright luggage case with the impact

absorbing wheel assembly.

Figure 2 is a perspective view of the impact absorbing wheel assembly

according to the instant invention.

Figure 3 is a side view of the device of Figure 2.

Figure 4 is a bottom view of the device of Figure 2.

Figure 5 is a rear view of the molded housing, partially disassembled, specifically designed for mounting on textile-based softsided luggage cases.

Figure 6 shows the basic parts of the spring apparatus and the wheel mounted on the lever.

Figure 7 shows the spring apparatus partially attached to the back side of the

mounting lever.

Figure 8 shows the spring mechanism positioned within the space between the

housing and the mounting lever (the mounting lever is not shown in this view).

Figure 9 is a view similar to Figure 8 with the rivet holding the spring assembly

in place.

Figure 10 is a side view of the mounting lever with the spring device in an

undeflected condition.

Figure 11 shows the wheel supporting the upright case in a vertical orientation

on a horizontal surface.

Figure 12 shows the wheel simulating the deflected position of the mounting

lever while a fully loaded case is being towed on a pair of such wheels.

Figure 13 simulates the deflection of the mounting lever when the front exposed

surface of the mounting lever impacts a curb or the like.

Detailed Description of the Preferred Embodiment

Referring to the figures, the preferred embodiment consists essentially of a

conventional wheel and bearing assembly mounted to a novel molded construction.

The inventive construction 10 consists of a wheel and bearing assembly 12, a mounting

lever 14 which is pivotally attached at one end 16 to the luggage case "C" and has a

generally elongated fork shape at the other end having a pair of tines 18 forming a "Y" shape. These tines or protrusions 18 provide a mounting fork into which the

conventional wheel and bearing assembly 12 is journaled on an axle 20. A second axle

22 passes through a properly sized, horizontally extending hole 24. It is about this

second axle that the mounting lever can pivot when the wheel is subjected to a force.

This second axle 22 passes through protruding wings or edges 26 of a mounting bezel

28. This mounting bezel 28 is made of an injection molded plastic, preferably the same

plastic that is used to make the mounting lever 14.

This bezel has an overall hollow corner construction which is sized to embrace

a lowermost corner of the packing case portion of an upright luggage case. The wheel system consists of two such mounting bezels, wheel assemblies, and mounting lever

constructions, each being a mirror image of the other. Preferably the mounting lever 14

is shaped so that one mold can be used for the levers at both the right and left corners of the luggage case. The mounting bezels 28 for each corner are mirror images of one

another. The mounting bezel has an elongated cavity 30 to receive and hold about half the volume of the mounting lever 14, with the other half of the mounting lever

protruding from the bottom edge of the mounting bezel as well as protruding from the

forward facing side of the mounting bezel. The mounting bezel also includes an

indentation 32 to receive the wheel, especially when the wheel is deflected into the

indentation 32 by the weight of the luggage case and by impacting bumps and barriers

during transport, as will be detailed. This elongated cavity also holds an arched leaf

spring 40 positioned between the back wall 34 of the cavity 30 and the inward facing surface of the mounting lever. The back of the mounting bezel 28 includes holes 36, 38 to respectively receive

mounting screws for attaching the bezel to the case and for attaching the lever arm and

spring assembly (Figure 6) to the bezel. Penetration 38 passes through the back wall of

the elongated cavity, through an upper portion of the leaf spring at 42 and into the

inward facing surface of the mounting lever. The leaf spring 40 has a hole 44 through

its center which normally aligns with another hole 38 through the back wall. These

aligned holes receive a blind rivet 50 (Figure 9), as will be detailed below. The penetrations and screw receiving studs 36 around the periphery of the mounting bezel

are used to fasten the bezel to the lower corner of the packing case.

The wheel and lever receiving cavity 30 further include a pair of protrusions 52

(Figures 4 and 8). These protrusions extend into slots 54 on the inner facing side of the

mounting lever. These protrusions help stabilize and guide the movement of the mounting lever as it rotates about the second axle 22 when affected by forces and

impacts, as will be detailed.

The mounting lever itself is a single, fairly complex injection molded plastic

part. Its inward facing surface includes a network of structural webs to provide a remarkable durability and stiffness, while minimizing the amount of plastic compound

used to form the lever, and thus minimizing the weight of the lever itself. There is also

a pair of mounting studs 56 to receive a pair of penetrating fasteners or screws which

also pass through the leaf spring's elongated holes 42.

The leaf spring 40 is made of a fairly heavy gage, tempered, sheet steel. The spring is in the shape of an elongated S-curve. Each end of the S-curve includes an elongated hole 42 for receiving a screw fastener. The center of the spring has a hole 44 for receiving a blind rivet 50 as mentioned above. There are pair of flanges 48 which protrude outwardly from the center portion of the spring directly in line with the center hole for the blind rivet. These flanges are normally held in respective receiving slots 58 molded into the inner surface of the mounting bezel's elongated cavity.

The final assembly process and sequence is fairly simple since there are only three basic sub-assemblies not counting the various axles and fasteners: the mounting lever and wheel assembly, the leaf spring, and the mounting bezel. As seen in the figures, the leaf spring is first attached to the mounting lever / wheel assembly by a first screw fastener passing through the elongated hole at the lowermost end of the leaf spring. This holds the leaf spring in position on the mounting lever, but only loosely since the ends of the spring will splay outwardly when the mounting lever is squeezed down on the spring as it rotates into the elongated cavity during travel. This assembly

(consisting of the now loosely attached leaf spring, the mounting lever, and wheel assembly) can be slid in to position within the elongated cavity by inserting the flanges 48 into the downwardly facing openings of the receiving slots 58. For clarity in Figures 8 and 9, the mounting lever has been removed to show how the leaf spring's laterally protruding tabs 48 are inserted into the downwardly open slots 58 molded into the elongated cavity. Once in this position, a blind rivet 50 affixes the leaf spring in position. Next, a penetrating fastener, specifically a longer screw 60, passes from the back side of the mounting bezel through the appropriate hole 38 through the bezel wall, the upper elongated hole in the leaf spring 42 and also into the back surface of the mounting lever 56. Finally, the mounting lever axle is fastened through the mounting bezel and mounting lever, thus completing the assembly.

Referring to Figures 10 through 13, the operation of the inventive wheel

assembly will now be detailed. Figure 10 shows the completed wheel assembly in an undeflected state. For reference, note the position of the wheel axle relative to the

lower outer corner of the mounting bezel. In this position, the wheel and mounting

lever are held by the mounting lever axle and the inter-engagement of the leaf spring on

the backside of the mounting lever and to the inner surface of the cavity of the mounting bezel. The leaf spring is not sprung or distorted from its normal shape since

it is under almost no compression. Figure 11 shows that the luggage case is in the

vertical position while resting on the two wheels and the conventional glides on the front face of the packing case portion. Again the mounting lever does not show any

appreciable deflection relative to the mounting bezel. The weight of the luggage case is

borne by a vertical force generally passing through the mounting lever axle. The leaf spring is subjected to very little if any compression force.

When the luggage case is being towed in the conventional manner, the weight of

the luggage case is borne more by the leaf spring. Thus the lever arm can be seen to

deflect back into the mounting bezel cavity (see Figure 12). The leaf spring is capable

of deflecting further if the tire portion of the wheel would impact a bump such as a

crack between floor tiles or gravel on the roadway. In this manner the impact is taken

up by the leaf spring and thus less of the vibration from such impacts will be absorbed

by the contents of the case and by the hand of the traveler while towing the upright case.

Figure 13 illustrates a further advantage of mounting the wheel on the forward

protruding mounting lever. Here a curb, stair tread or similar obstacle is simulated

impacting the leading edge or protruding face of the mounting lever. In a conventional

upright luggage case, this impact would be taken directly by a skid plate or mounting

bezel fixed to the forward face of the packing compartment. Here, however, the

impact is taken by the mounting lever which is isolated from the luggage case by the leaf spring. Thus the leaf spring can deflect further into the elongated cavity to help

absorb impact with curbs, stair treads and such barriers.

Thus, the novel wheel construction can help isolate and absorb two sources of impact and vibration normally encountered when towing an upright luggage case,

specifically, vibration from the wheeling over a bumpy floor surface, as well as impact

and vibration from encountered obstacles such as a curb or edge of a stair step.

Claims

CLAIMS:

1. In an upright luggage case having a wheel assembly for wheeling a luggage case

across the horizontal surface, the improvement comprising a mounting bezel, a

generally vertically extending elongated mounting lever for carrying a rotatably mounted wheel, a rotatable mounted wheel mounted at a lowermost portion of

the mounting lever, and an axle for attaching the mounting lever to the mounting bezel mounted vertically above the wheel, a spring positioned

between an intermediate portion of the mounting lever and the mounting bezel.

2. A wheel assembly as set forth in Claim 1 wherein the mounting lever is positioned to protrude forward of the mounting bezel such that when mounted

on an upright case the mounting lever will impact and engage an obstacle, such as a curb or stair step, when the upright case is wheeled over the obstacle.

3. A wheel assembly as set forth in Claim 1 wherein the spring is a leaf spring.

4. A wheel assembly as set forth in Claim 3 wherein the leaf spring has holes

therethrough for attaching it to the bezel and to the mounting lever.

5. A wheel assembly as set forth in Claim 2 wherein the bezel has a cavity sized to

receive only a portion of the mounting lever.