GB2396100A

GB2396100A - A castor wheel assembly having a spring shock absorber

Info

Publication number: GB2396100A
Application number: GB0228764A
Authority: GB
Inventors: Te-Hsin Hsiao
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-12-10
Filing date: 2002-12-10
Publication date: 2004-06-16
Also published as: DE20219351U1; GB0228764D0

Abstract

A castor wheel assembly comprises a bracket (51) to hold a wheel (5), a through shaft (4), threaded at both ends is pivotally attached to the bracket by a nut (55 fig 3) and rotates via bearings (521 and 522 fig 3). Springs (6 and 7) of different diameters are located at opposite ends of the through shaft. The springs serve to support the weight of the load and to absorb any shock loading caused by a surface irregularity. Vertical movement of the assembly is obtained by leg (1) sliding up and down relative to tube (2) . Rotational movement between the tube and the leg is prevented by three profiles (21) formed on the outside of the tube, these mate with corresponding female profiles (12) on the leg. The castor assembly is intended for use in applications such as hospital beds.

Description

: 2396 1 00

TITLE: A SHOCK ABSORBER STRUCTURE OF A CASTOR WHEEL

BACKGROUND OF THE INVENTION

(a) Technical Field ofthe Invention

The present invention relates to shock absorber, and in particular, to shock 5 absorber which employed in castor wheel, allowing the castor wheel to pass an obstacle smoothly.

(b) Description of the Prior Art

In order to facilitate the transportation of patients on a hospital bed, or of equipment on a platform with rollers, and moves in 360 degree, these rollers 10 or castor wheels are mounted directly onto the bottom end ofthe support connected to the platform ofthe hospital bed. However, when the hospital bed or the castor wheels pass an obstacle or uneven ground, the shock that generated by the ground may hurt the patient, in particular, when the castor wheels pass through a hole found on the floor or ground. No shock 15 absorbing device is provided to the castor wheels and therefore any shock will directly be transferred to the support then to the bed. Accordingly, it is an object of the present invention to provide a shock absorber structure of a castor wheel which will mitigate the above drawbacks.

SUMMARY OF THE INVENTION

Accordingly, it is an object ofthe present invention to provide a shock absorber structure of a castor wheel, the bottom section of a leg is inserted with a mounting tube and the circumferential edge ofthe leg is mounted with 5 a protective hood. A screw nut is used to lock the mounting tube and the protective hood to the bottom section ofthe leg. The interior ofthe protective hood and the mounting tube are inserted with an insertion shaft having a bottom section passed through between two bearings on the seat of the castor and a screw nut locks the seat at the bottom section ofthe through 10 shaft such that the seat can be freely rotated with the through shaft as the shaft center. Further, the top and the bottom section ofthe through shaft are respectively mounted with a spring to form into top and bottom buffer. The buffer is effectively used as the shock produced as a result of uneven ground and allowing the castor wheel to pass an obstacle.

15 The foregoing object and summery provide only a briefintroduction to

the present invention. To fully appreciate these and other objects ofthe present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the

invention and the claims should be read in conjunction with the accompanying 20 drawings. Throughout the specification and drawings identical reference

numerals refer to identical or similar parts.

Many other advantages and features ofthe present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred

5 structural embodiment incorporating the principles ofthe present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG 1 is a perspective exploded view of a shock absorber structure of a castor wheel in accordance with the present invention.

FIG 2 is a perspective view of a shock absorber structure of a castor 5 wheel in accordance with the present invention.

FIG 3 is a sectional view of He shock absorber structure of a castor wheel in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following descriptions are of exemplary embodiments only, and are

not intended to limit the scope, applicability or configuration ofthe invention

in any way. Rather, the following description provides a convenient

5 illustration for implementing exemplary embodiments ofthe invention.

\'arious changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope ofthe invention as set forth in the appended claims.

Referring to FIG 1, there is shown a shock absorber structure of a castor 10 wheel having a leg 1, a mounting tube 2, a protective hood 3, an insertion shaft 4, a castor wheel 5 and a top and a bottom spring 6, 7.

Referring to FIGS. 2 and 3, the leg 1 is a tubular tube having three protruded stripes 11 within the internal wall thereof, and divide into fan-like insertion slot 12 and a bolt hole 111 is formed on a protruded stripe 11, and the 15 mounting tube 2 matches the inner wall ofthe leg 1 and has a hexagonal hole, and the external edge is provided with three fan-like filing blocks 21 for the mounting ofthe bottom section ofthe leg 1, and the top end thereofis locked with a cap 22 and the bottom end is screwed with a circular base seat 23, the center of the cap 22 is provided with a circular hole 221 and the bottom seat 20 23 urges the lower section of the leg 1, and the center of the bottom seat 23 is

provided with a hexagonal hole for connection with the mounting tube 2, and the bottom seat 23 is provided with a securing hole 232; the protective hood 3 is mounted at the external edge of the leg 1 and the bottom seat 23, and the inner surface is provided with a horizontal partition board 31 having a through 5 hole for the communication with the interior ofthe mounting tube 2, and the circumferential edge is provided with three groups of mounting holes 312; the shaft 4 is hexagonal and has a top and bottom portion extendingly mounted with circular supports 41, 42, the end edge ofthe circular supports 41,42 is threaded; the castor wheel 5 is pivotally mounted to the lower section of the 10 seat 51 having a protruded block 52, the top and the bottom section of the protruded block 52 is provided with a bearing seat 521,522 mounted with bearings 53,54, a circular insertion hole 523 is located between two bearing seats 521, 522, the springs have different diameter and are respectively mounted onto the top and bottom section ofthe shaft.

15 The circular support passes through the space between the two bearings 53,54 such that the support comes out from the bottom edge ofthe bearings 53,54 and a nut 55 is mounted from the bottom end ofthe threaded portion 421 and the seat 51 is mounted at the lower section ofthe shaft 4, and the top section ofthe shah 4 is mounted from the bottom end of the protective hood 3 20 lo pass through the through hole and the communication hole at the base seat

23, and via the circular hole at the cap 22 center, and the circular support is extended into the interior ofthe leg 1 and the springs 6, 7 are respectively urge the bottom face ofthe cap 22 and the top edge ofthe hexagonal shaft, and the bottom face ofthe protective hood 3 and the top edge ofthe protruded block 5 52, and screw nut 55 via the mounting hole, securing hole, the castor wheel is mounted to the bottom section ofthe leg 1, and the shock ofthe castor wheel is absorbed.

The top end bottom springs 6, 7 are formed of different coil diameter, and are respectively mounted onto the top and bottom section of the through shaft 10 4. The top and the bottom springs 6, 7 are mounted within the interior ofthe mounting tube 2 and are pressed against the bottom face ofthe cap 22 and between the top edge ofthe hexagonal shaft ofthe through shaft 4 to resist the shock produced at the castor wheel at the through shaft 4. The top and bottom spring 7 is adapted between the protective hood for absorbing shock 15 generated due to uneven ground, avoiding the shock being transferred to the leg 1.

In accordance with the present invention, when installation, an appropriate length ofthe leg l is cut for use in, for instance, hospital beds.

The mounting tube 2 is mounted from the bottom end of the leg 1. The 20 protective hood 3 and the bottom end of the leg 1 are mounted to each other.

The protective hood 3 and the top spring 6 are mounted from the top end of the through shaft. The top end of the through shaft 4 is mounted from the bottom section ofthe mounting tube 2 and then adjust the combination hole 312 of the protective hood 3, and the securing hole 232 at the bottom seat 23 5 ofthe mounting tube 2, and the bolt hole 111 ofthe leg 1 so that these holes are in aligned with each other. After that screw nut 32 is used to mount therebetween for securing. Next, the bottom spring 7 and the castor wheel 5 are mounted, and finally, the top end ofthe leg 1 is secured at the cover section ofthe bed.

lO The hospital bed after mounted with the castor wheel in accordance with the present invention can withstand a maximum load of 200 kg for each wheel.

Therefore, the bed can withstand a load of 8000 kg and when the bed passes a hump or an obstacle, the shock that generated by the uneven ground will pass through the top and bottom springs 6, 7 at the through shaft 4 and the shock 15 will be absorbed and will not transfer to the leg 1, facilitating the smooth movement of the bed.

A mounting tube 2 is locked at the bottom section of the leg 1 for the top mounting ofthe through shaft 4, and by the upward displacement, the top section of the through shaft ó passes through the bearings 53, 54 on the seat 51 20 such that the seat 51 can freely rotate about the through shall as the shaft

center. By means ofthe cap 22 and the top and bottom springs 6, 7 the bed with the castor wheel will absorb the shock due to the uneven ground or obstacle.

The shock absorber is effectively for absorbing the shock that generated.

5 It will be understood that each ofthe elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

While certain novel features ofthis invention have been shown and described and are pointed out in the annexed claim, it is not intended to be 10 limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details ofthe device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit ofthe present invention.

Claims

I CLAIM:

1. A shock absorber of castor wheel having a leg, a mounting tube, a protective hood, a shaft, a top and bottom compression springs wherein the leg is a tubular tube having three protruded stripes within the internal wall, and 5 divide into fan-like insertion slot and the bolt hole is formed on the protruded stripe, and the mounting tube matches the inner wall ofthe leg and has a hexagonal hole, and the external edge is provided with three fan-like filing blocks for the mounting ofthe bottom section of the leg, and the top end thereofis locked with a cap and the bottom end is screwed with a circular tease 10 seat, the center ofthe cap is provided with a circular hole and the bottom seat urges the lower section ofthe leg, and the center ofthe bottom seat is provided with a hexagons hole for connection with the mounting tube, and the bottom seat is provided with a securing hole; the protective hood is mounted at the external edge ofthe leg and the bottom seat, and the inner surface is provided 15 with a horizontal partition board having a through hole for the communication with the interior ofthe mounting tube, and the circumferential edge is provided with three groups of mounting holes; the shaft is hexagonal and has a top and bottom portion extendingly mounted with a circular support, the end edge of the circular support is threaded; the castor wheel is pivotally mounted 20 to the lower section of the seat having a protruded block, the top and the

bottom section ofthe protruded block is provided with a beating seat mounted with a bearing, a circular insertion hole is located between two bearing seat, the springs have different diameter and are respectively mounted onto the top and bottom section of the shade; thereby the circular support passes through the 5 space between the two bearings such that the support comes out from the bottom edge of the bearing and a nut is mounted from the bottom end of the threaded portion and the seat is mounted at the lower section ofthe shaft, and the top section ofthe shaft is mounted from the bottom end of the protective hood to pass through the through hole and the communication hole at the base 10 seat, and via the circular hole at the cap center, and the circular support is extended into the interior ofthe leg and the springs are respectively urge the bottom face ofthe cap and the top edge of the hexagonal shaft, and the bottom face ofthe protective hood and the top edge ofthe protruded block, and screw nut via the mounting hole, securing hole and the mounting hole, the castor 15 wheel is mounted to the bottom section ofthe leg, and the shock ofthe castor wheel is absorbed.