Two-Way Band Brake for a Caster

Abstract

A mechanical two-way controlled band brake has components, such as a lever, a yoke having arms and a guiding bar, a brake band, anchoring points, pivots and brake drums, which are preferably made of metal or metal alloys. The components of the mechanical two-way controlled band brake may be also made of other materials, such as plastics, combination of metal alloys and plastics or any other materials, which are firm with sufficient bearing capacity.

Claims

1. A mechanical two-way band brake for a caster comprising: a vertical axis pivot, a control member, a fork, and a lever that bears on a yoke at least on one end of the lever, whereas the yoke comprises at least one anchoring point on at least one arm of the yoke and is coupled to the fork, whereas the anchoring point is supported by a support of the fork and simultaneously located in a yoke slot of a guiding bar, whereas the yoke is supported free on the support of the fork and in parallel is supported by a spring, whereas in addition the yoke comprises ends and the at least one anchoring point comprises at least one anchoring point at each of the ends of the yoke to fix a brake band to the yoke, wherein the brake band encircles a brake drum of the caster in spiral.

2. The mechanical two-way band brake according to claim 1, wherein the at least one arm and the anchoring points comprise at least two bearing arms with anchoring points for fixing of the yoke and at least two bearing arms with anchoring points for fixing the brake band.

3. The mechanical two-way band brake according to claim 2 wherein the at least two anchoring points are simultaneously pivots should the yoke be in braked position.

4. The mechanical two-way band brake according to claim 1 wherein the brake band comprises lugs in each end to fix the brake band to the anchoring points of the yoke whereas the yoke is flexibly vertically movable in a body of the yoke.

5. The mechanical two-way band brake according to claim 1, wherein the brake band is metal.

6. The mechanical two-way band brake according to claim 1, wherein the brake band is made of materials selected from a group of materials consisting essentially of metal alloys, metal wire, plastics, and plastic alloys.

7. The mechanical two-way band brake according to claim 1, wherein the yoke is one unit and the at least one arm comprises four arms and the anchoring points comprise four anchoring points and the yoke is metal.

8. The mechanical two-way band brake according to claim 1, wherein the yoke is one unit and the at least one arm comprises four arms and the anchoring points comprise four anchoring points and the yoke is made of materials selected from a group of materials consisting essentially of metal alloys, metal wire, plastics, and plastic alloys.

9. A method of braking a two way band brake the method comprising the step of: releasing a lever releases a yoke by which position of the yoke changes and a brake band shrinks around a brake drum, whereas change of the yoke depends on a direction of rotation of the brake drum of a caster.

10. The method of braking according to claim 9, wherin releasing the lever bearing onto the yoke changes the position of the yoke by a spring and thus the brake band shrinks around the brake drum.

11. A method of braking a two way band brake the method comprising the step of; pressing a lever onto a yoke presses a spring and at least two anchoring points bear onto a support of the yoke, whereas a brake band releases around a brake drum and releasing of the brake drum enables free rotation of a caster.

Description

LIST OF DRAWINGS

[0019] The FIG. 1 shows side elevation of a cross section of a caster with two-way controlled band brake.

[0020] FIG. 2 shows axonometric projection of a caster with open view of the caster showing the visible part of the two-way controlled band brake.

[0021] FIG. 3 shows axonometric projection of an inner arrangement of the two-way controlled band brake without the inner drum.

EXEMPLARY EMBODIMENTS OF THE INVENTION

[0022] FIG. 1 shows a caster 1. Preferably, this caster may be used with beds, hospital and nursery support apparatuses, tables, side tables, counters, trolleys or any other type of furniture that needs to be moved from place A to the place B. Hospital and nursery facilities and setting need to handle patient support apparatuses empty or with patients due to necessary transport from one part of such facility to another, transport to examine a patient etc.. The hospital and nursery facilities and settings are not shown on the FIG. 1.

[0023] FIG. 1 shows side elevation of a cross section of a caster 1 with two-way controlled band brake. The two-way controlled band brake comprises a caster 1 with inner brake drum 7. The caster 1, with the brake drum 7 is fixed to a fork fusing swivel pin 6 and via opening 16 for swivel pin 6. The brake drum 7 is twined around by brake band 8, which is terminated in each end by a lug 15 for attaching the brake band 8 to the symmetric yoke 10 of the two-way controlled band brake. It means that the brake band 8 has two lugs 15. At least one lug 15 is fixed to at least one external anchoring point 12a of the yoke 10 and at least one lug 15 is fixed to the anchoring point 12b of the yoke 10. The yoke 10 of the two-way controlled band brake is formed, in the preferred embodiment, as one symmetrical unit which has in each end at least one anchoring point 12. Optionally, the yoke 10 can be formed from several parts: body of the yoke 10 and four arms 17 that may be divided into two long arms 17a and 17b terminated with anchoring points 12a and 12b. These arms 17a and 17b are bearing arms for brake band 8 whose anchoring lugs 15 are fixed to the arms on anchoring points 12a and 12b. The second pair of arms comprises short arms 17c and 17d which are terminated by anchoring points 12 in the end but after fixing into the yoke slots 13a and 13b in the guiding bar 11 of the yoke they shall be defined hereinafter as pivots 18a and 18b. This pair of short arms 17c and 17d with pivots 18a and 18b serve as bearing arms for fixing the yoke 10 in the guiding bar 11 of the yoke which comprises two yoke slots 13a and 13b and a support 14 where the yoke 10 is free fixed to the fork 4. In parallel, free supporting of the yoke 10 enables free movement of the yoke 10 in yoke slot 13a by means of pivots 18a and 18b, or in yoke slot 13b on the fork 4 by means of a spring 9 that is located under the yoke 10 between the pivots 18a and 18b. The spring 9 bears on the support 14 of the fork 4. in the preferred embodiment, the guiding bar 11 of the yoke 10 with yoke slots 13a and 13b and the support 14 for the spring 9 are parts of the fork 4 (carrying member). Optionally, the guiding bar 11 of the yoke 10 with yoke slots 13a and 13b and the support 14 for the spring 9 fixed to the fork 4 as an external component by nuts or screws.

[0024] The FIG. 1 also shows that the caster 1 comprises vertical axis pivot 2 and a fork 4 (carrying member). A control member 3 which controls a lever of a spring support 5 goes through the vertical axis pivot 2, The lever 5 is controlled by a control member 3 in one end and in another end the lever 5 bears on the yoke 10 by which the two-way band brake is controlled. By releasing the lever 5 bearing onto the symmetrical yoke 10 the yoke 10 changes its position and the brake band 8 shrinks around the brake drum 7 by which the caster 1 is braked. Position of yoke 10 and shrinking of the brake band 8 around the brake drum 7 change in consequence of direction in which the caster 1 moves. When braking the caster 1 the lever 5 releases onto the yoke 10 and the brake band 8 shrinks around the brake drum 7. Thus the caster 1 is stopped and turning around axis of rotation in random direction is limited. The change of yoke 10 position upon releasing the lever 5 onto the yoke 10 and change of direction of rotation of the brake drum 7 have a substantial impact for braking by two-way controlled band brake.

[0025] When changing the position of the symmetrical yoke 10 upon releasing external force of lever 5 onto the yoke 10 the brake band 8 shrinks around the drum by means of a spring 9, When the caster 1 moves in the first phase, the spring 9 does not develop sufficient force to brake the brake drum 7 of the caster 1. At the moment the lever 5 is released onto the yoke 10. the yoke 10 leans and bears on the guiding bar 11 of the yoke according to direction of caster rotation and thus force is developed which consequently shrinks the brake band 8 around the brake drum 7 which brakes the caster 1, Change of position of the yoke 10 is enabled by symmetry of the yoke 10 therewith that the yoke 10 changes position into the opposite direction of ride. By changing position of the yoke 10 into the opposite side the caster 1 may be braked even during opposite direction of ride. During this change of position of the yoke 10 at least one anchoring point 12 in the guiding bar 11 of the yoke is in the distant position from the caster centre and one anchoring point 12, or pivot 18a or 18b, comes closer to the caster centre by which the brake band 8 is shrunk around the drum 7. This change is caused by transferring the external force of the lever 5 onto the yoke 10 by means of spring 9 which is located between the pivots 18a and 18b.

[0026] The caster 1 is unbraked when the brake band 8 releases. This happens at the moment of pressing the lever 5 onto the yoke 10 by which the anchoring points 12 and the yoke 10 come closer to the centre of the caster 1. If the yoke 10 is in such position, the brake band 8 remains free and the brake drum 7 of the caster 1 can rotate free in any direction, it means forward or backward, from left to right.

[0027] The FIG. 2 shows the axonometric side elevation with open part of the caster 1 with visible brake drum 7 which encircles the brake band 8, The brake band 8 is fixed to at least one anchoring point 12a of the symmetrical yoke 10 by lugs 15 and in opposite end to the anchoring point 12b of the yoke 10. Optionally in preferred embodiment, the brake band 8 is anchored by two lugs 15 to two arms 17a and 17b of the yoke 10 so that each end of the brake band 8 could be anchored on different arm of the yoke 10.

[0028] The following figure will show obviously that the lugs 15 of the brake band 8 are each anchored on the different side of the yoke 10 by means of anchoring points 12a and 12b, To reach proper and sufficiently tight shrinking of the brake band 8 around the brake drum 7 at least one lug 15 of the brake band 8 is fixed to the anchoring point 12a, which is located outside (outward) the yoke 10. it means closer to the fork 4. Additionally, at least one lug 15 of the brake band 8 is fixed to anchoring point 12b, which is located inside (inward) the yoke 10, it means farther from the fork 4 toward the inner hollow space of the caster 1. All mentioned components are not shown on the FIG. 2 entirely however are visible on the other figures.

[0029] The anchoring point 12 may have a form of a projection from the yoke 10 or additionally attached pin, rivet or other convenient securing member. The caster 1 comprises a vertical axis pivot 2, a control member 3 and a fork 4 to which the caster 1 is fixed to by swivel pin 6. The body of the caster 1 comprises a brake drum 7, which is encircled by brake band 8, It means that the brake drum 7 described herein is an integral part of the caster 1, however, optionally the brake drum 7 may be fixed to the caster 1 body externally by rivets, screws, nuts or any other joining members. The FIG. 2 also shows that the fork 4 comprises an opening 16 for swivel pin 6.

[0030] The FIG. 3 shows axonometric projection of the inner arrangement of the band brake system without the inner brake drum 7 and external cover of the caster 1. The FIG. 3 shows a vertical axis pivot 2, a control member 3, a fork 4 with a lever 5, which is coupled with the control member in one end and in another end the lever 5 bears on the centre of the symmetrical yoke 10. The symmetrical yoke 10 comprises anchoring points 12 on each end. In this embodiment the yoke 10 is one unit, optionally the yoke 10 may comprise four arms 17, whereas one pair of arms 17a and 17b are long arms with anchoring points 12a and 12b in the ends into which the brake band 8 is fixed by lugs 15. In addition the yoke 10 comprises also short arms 17c and 17d with anchoring points 12c and 12d, which may have function of pivots 18a and 18b if the yoke 10 is in braked position.

[0031] Anchoring of the brake band 8 is provided by lugs 15 for fixing the brake band 8, which are attached on opposite sides of the yoke 10 contrarily against each other so that the brake band 8 could form a spiral for braking. The lugs 15 are made by plate of the brake band 8 and have a shape of a loop. Optionally, the lugs 15 may be formed, same as the brake band 8, by metal wire or a circle on the metal wire. The brake band 8 may be made of other materials which will be resistant sufficiently for repeated braking of brake drum 7.

[0032] The yoke 10 comprises at least one anchoring point 12 in each opposite end for fixing the brake band 8. In the preferred embodiment, this anchoring point 12 on the yoke 10 has a form of a metal projection, which projects on both sides of the yoke 10 as shape T, but may be shaped differently to anchor the brake band 8 which encircles the inner brake drum 7. The brake drum 7 is not shown in the FIG. 3. The FIG. 3 shows also that the yoke 10 is one unit having four arms 17, whereas two arms 17a and 17b are long arms determined for hanging up and controlling of the brake band 8, and another two arms 17 are short arms 17c and 17d, which are determined for anchoring the yoke 10 into the guiding bar 11 of the yoke in yoke slots 13 that are not shown in this FIG. 3, The yoke 10 bears on the support 14 of the yoke which is a part of the fork 4 (carrying member). All arms 17 are capacity bearing arms 17 of the yoke 10, whereas always at least two arms 17 have different function than the other two arms 17. The FIG. 3 shows that the yoke 10 bears on the support 14 by both anchoring points 12c and 12d, whereas a spring 9 is located between the yoke 10 and the support 14. The anchoring points 12c and 12d are simultaneously also pivots 18a and 18b should the yoke 10 be in braked position. The FIG. 3 shows that the lever 5 bears on the yoke 10, and in such position the brake band 8 around the brake drum 7 (not shown) is free and the caster 1 may move free. In case the lever 5 is released, which means that the lever 5 does not bear onto the yoke 10 and frees its position, the yoke 10 will change the position therewith that at least one pivot 18a or 18b moves away from the centre of the caster 1 according to which direction the caster 1 rotates to and the brake band 8 shrinks around the brake drum 7 (which is not shown in this figure). The change of position of the yoke 10 and the lever 5 enables the yoke 10 to shrink the brake band 8 around the brake drum 7 and thus stop the caster 1. Change of position of the yoke 10 depends on direction of rotation of the caster 1.

[0033] All components of the mechanical two-way controlled band brake such as lever 5, yoke 10, arms 17a, 17b, 17c, 17d of yoke, guiding bar 11 of yoke, brake band 8, anchoring points 12, pivots 18 and brake drums 7 are made of metal or metal alloys in the preferred embodiment. The above mentioned components of the mechanical two-way controlled band brake may be also made of other materials such as plastics, combination of metal alloys and plastics or any other materials which are firm with sufficient bearing capacity.

LIST OF REFERENCES

[0034] 1) caster [0035] 2) vertical axis pivot [0036] 3) control member [0037] 4) fork (carrying member) [0038] 5) lever [0039] 6) swivel pin [0040] 7) brake drum [0041] 8) brake band [0042] 9) spring [0043] 10) yoke [0044] 11) guiding bar (of a yoke) [0045] 12) anchoring point (a, b, c, d) [0046] 13) yoke slot (a, b) [0047] 14) support (of a yoke and a spring) [0048] 15) lug (for fixing of brake band) [0049] 16) opening (for swivel pin of a carter) [0050] 17) arms: [0051] 17a, 17b – long arms [0052] 17c, 17d – short arms [0053] 18) pivot (a, b)