WO2025201638A1

WO2025201638A1 - Swivel castor

Info

Publication number: WO2025201638A1
Application number: PCT/EP2024/058275
Authority: WO
Inventors: Robert VOM STEIN; Athanasios Molozis
Original assignee: Tente GmbH and Co KG
Current assignee: Tente GmbH and Co KG
Priority date: 2024-03-27
Filing date: 2024-03-27
Publication date: 2025-10-02
Anticipated expiration: 2026-09-27

Abstract

The invention relates to a swivel castor (1) comprising a wheel (4) and a fork (11), wherein the wheel (4) has an outer tread (5) and is rotatable received in the fork (11), the fork (11) having a generally U-form with two U-legs (16) and a U-web (17). For providing a swivel castor and certain parts thereof, the castor being suitable as part of a device to be moved, especially to be moved by a person when pushing the device, it is proposed that the U-legs (16) and the U-web (17) being materially uniform, the fork (11) being a metal part build from a metal strip by punching in view of outer contour (19) and inner contour (18) and further by bending, the U-web (17) being materially uniform with the U-legs (16), wherein the U-web (17) has an area of smaller thickness (d) compared to the thickness (d') of the U-legs (16). The castor may have first and second sealing caps (39, 40).

Description

Swivel castor

Field of Disclosure

[0001] Disclosed is a swivel castor comprising a wheeland a fork, wherein the wheel has an outer outer tread and is rotatable received in the fork, the fork having a generally U-form with two U-legs and an U-web.

Background

[0002] Castors as mentioned are known from various state of the art such as WO 2019/053004 Al (US 2021/0061003 Al). A fixed castor is known from e.g. WO 2014/202454 Al (US 2016/0144709 Al). A swivel castor with an electrical break is known from DE 102018 115 729 Al.

[0003] Starting from the state of the art mentioned, the disclosure is concerned with the problem providing a swivel castor and certain parts thereof, the castor being suitable as part of a device to be moved, especially to be moved by a person when pushing the device.

Summary

[0004] A possible embodiment provides a fork for supporting a wheel, especially a fork for use in a castor as disclosed here. The fork has, as already mentioned, a generally U-form with two U-legs and a U-web. Specifically, the U- legs and the U-web being materially uniform, the fork being a metal part build from a metal strip by punching in view of an outer contour and an inner contour and further by bending, the U-web being materially uniform with the legs, wherein the U-web at least a part thereof, has a smaller thickness than the U- legs. [0005] The fork can provide an improved space for receiving further parts of a castor, internally concerning the fork. In view of the nevertheless material uniform design, the necessary stability is not relevant deteriorated thereby. The U- web, at least a part thereof, with the reduced thickness, is not subjected to the same forces as the U- legs are. Since the fork is a metal part being in this respect producible only by punching and bending, the fork is nevertheless rationally producible. The U-web may have a generally circular bent out region.

[0006] The bent out region may be a basis for a tube part, combined with the fork at the bent out region. The tube part may be welded to the bent out region.

[0007] The tube part can receive a mechanical bearing such as a ball bearing. The bent out region can improve stability despite of a possibly reduced thickness. This mechanical bearing may be a swivel bearing between the mounting stem and the fork.

[0008] A further possible embodiment provides the wheel of the castor, having a fork, possibly with one or more features as disclosed here, being brakeable by positive lock by an engagement part provided on the fork and movable from radial outwards into spaces between teeth circumferentially arranged on the wheel, the engagement part being actuatable by an actuation bolt received within the mounting stem, the engagement part further being arranged on a swivel part attached to the fork, the swivel part being fork-shaped, having a first and a second yoke part and two legs extending from opposite ends of the yoke parts and substantially across to the yoke parts, with the yoke parts extending over the wheel above a tread of the wheel and the first yoke part crossing a linear prolongation of the actuation bolt, for the first yoke part moving on a circular path being actuated by the actuation bolt moving in a straight line. [0009] The castor equipped with such positive lock has the relevant parts outside of the wheel cooperating with an outer surface of the wheel. The outer surface of the wheel may provide the teeth. The actuation bolt may act directly on the first yoke part. With acting on the first yoke part, relative motion between the first yoke part and the actuation bolt may take place.

[0010] A further possible embodiment provides for a castor, especially a castor according to one of the embodiments disclosed here. The hub being sealed by a first and second sealing cap, extending essentially across to a rotation axis of the wheel, the caps being on its outer circumference sealed to a ring part of the wheel, the ring part having on its outer side a tread, each of the sealing caps being sealed against the rotation axis going through the sealing caps, the wheel being rotationally lockable by an interaction of an engagement part moveable from radially outside into spaces between circumferentially arranged teeth provided on the wheel, the engagement part being supported on the fork, one of the first and second sealing cap having the teeth on its outside. The castor with such sealing caps is protected against invasion of dust or fluid from outside. At once at least one of the sealing caps, and preferably only one, has the additional function serving as part of the rotational lock. The fork may extend by means of its U-legs outside to the sealing caps.

[0011] A further possible embodiment provides for a swivel castor comprising a wheel, a fork and a mounting stem, wherein the wheel is journaled rotatable in the fork and the fork is swivelable attached to the mounting stem, wherein further a rotational locking of the wheel and the swivel locking of the fork is provided for, at least one of the swivel locking and the rotational locking being possible by a mechanical lock. Further is provided a push rod with a plate part moving with the push rod. Further is provided a detection means in order to ascertain the position of the push rod by means of a contact element, being al- ways in direct contact to the plate part. The position of the contact element is preferably ascertainable by means of electrical switches actuatable by the engagement part.

Brief Description of the Drawings

[0012] The disclosure is explained in more detail below with reference to the accompanying drawing, which is merely an example of an embodiment. It shows:

Fig. 1 a hospital bed with a swivel castor;

Fig. 2 a perspective view of the swivel castor without design caps, with partly opened fork leg; Fig. 3 a fork of the swivel castor, perspective view;

Fig. 4 the fork according to Fig. 3, seen from above;

Fig. 5 the fork according to Fig. 3, front view;

Fig. 6 a vertical section through the fork according to Fig. 3;

Fig. 7 part of the fork according to Fig. 3, with a cable guiding and se- curing part;

Fig. 8 the fork according to Fig. 3, with the cable guiding and securing part;

Fig. 9 a side view of the wheel; Fig. 10 a vertical, in part perspective, section through the wheel;

Fig. 11 an enlarged part of Fig.10;

Fig. 12 an enlarged part of Fig.10;

Fig. 13 an enlarged part of Fig.10;

Fig. 14 an explosion view of the wheel;

Fig. 15 a vertical section through the wheel, across to rotation axis;

Fig. 16 a swivel part;

Fig. 16a the swivel part according to Fig. 16, partly in section;

Fig. 16b part of the swivel part according to Fig. 16, 16a, in combination with a push rod;

Fig. 16c a respective explosion view of the parts second yoke part, en- gagement part and slider;

Fig. 17 a vertical section through the fork combined with the connector stem, neutral position; Fig. 17a an representation according to Fig. 17, directional lock position;

Fig. 17b a representation according to Fig. 17, total lock position; Fig. 18 an enlarged part of Fig.17;

Fig. 19 an enlarged part of Fig.17; and

Fig. 20 an explosion view of the castor.

Detailed Description of the illustrated embodiments

[0013] Disclosed is first with reference to figures 1 and 2 a swivel castor 1 and a possible implementation and/ or a possible control of a moving part with such swivel castor 1. The moving part as shown in figure 1 is a hospital bed 2. It can be however also a workshop trolley, and equipment trolley or other moving support. The reference below and above to a hospital bed does always also include, that it might be a workshop trolley et cetera as mentioned.

[0014] The swivel castor 1 does have a mounting stem 7. By means of the mounting stem 7, the swivel castor 1 is receivable, and at the embodiment of Fig. 1 received in a fitting aperture 8 of the hospital bed 2. The mounting stem 7 does have an upper free end 9 and a lower end 10. The section between the upper free end 9 and the lower end 10 provides an insert section by which the mounting stem 7 is receivable in the fitting aperture 8. Preferably, the section between the upper free end 9 and the lower end 10 is cylindrical.

[0015] A lower part of the swivel castor 1 is swivelable relatively to the mounting stem 7 about a vertical axis y. The lower part does essentially comprise the wheel 4 and a fork 11 in which the wheel 4 is journaled. The wheel 4 is rotation- ally lockable as further described below and the fork is swivel - lockable. The rotational lock and/ or the swivel lock is a mechanical lock as also further described below. [0016] Swivelable with the fork 11 are also the locking means for the rotational lock.

[0017] The connection part 12 is preferably fixed with the mounting stem 7. Therefore, also the connection part 12 is not swivelling irrespective of which direction the fork 11 takes relatively to the connector stem 7.

[0018] Specifically, by means of the connection part 12, the electrical connection to a battery 99 in the hospital bed 2 can be made. The hospital bed 2 can also have an electrical connection part 100, for electrical connection to a supply in a housing such as a hospital, especially in case the hospital bed 2 is stationary on a certain place. The hospital bed 2 may also have a controller (not shown) which might be provided near to the battery or in a compartment housing also the battery or separate therefrom.

[0019] With reference to Figures 3 to 8, the fork 11 is described in further detail.

[0020] The fork 11 has a generally U-form, with two U-legs 16 and a U-web 17. The U-legs 16 and the U-web 17 are preferably materially uniform. Especially, these parts may be made from a metal part. The metal part may be a metal strip, which can be first designed as to its contour by punching. This may refer to an inner contour 18 and/ or an outer contour 19. The inner contour may encompass also holes 18a, 18b.

[0021] The generally U-form is preferably accomplished by bending, e. g. by bending the mentioned metal strip. Due to the bending, the U-legs 16 extend in an approximately right angle to the U-web 17. [0022] According to a possible embodiment, the U-web 17, preferably only concerning a certain area 20a (see below), does have a smaller thickness d then the U-legs 16, which have the thickness d ' . Practical values for d can be between 2,0 and 2,4 mm and for d' between 3,2 and 3,8 mm. The difference in thickness can be starting from d'20% or more or 60% or less. The difference in thickness may especially provide additional space beneath the U-web 17. The difference in thickness may be the result of a certain forming process. The original metal strip may have a same thickness throughout. The part which shall be the U- web, preferably only said area, may be reduced in thickness by the process.

[0023] The U-web 17 has further preferably a generally circular bent out region 20. Combined with the U-web 17 is preferably also a tube part 21. The tube part 21 can be welded to the U-web 17. The tube part 21 is preferably provided for on the U-web 17 on a side facing away from the U-legs 16. Further preferably, the tube part 21 is welded to the bent out region 20. The tube part may serve to receive a bearing 102, see further below.

[0024] The U-web 17 may have the opening 18 for directional lock, as further described below. The opening 18, as mentioned, might also be punched out.

[0025] Preferably, only on the bent out region 20 is the area realized with the reduced thickness d. This allows for an increase in free space below the bent out region.

[0026] On a transition of a U-leg 16 to the U-web 17, the fork 11 may have one or more beads 22. The beads 22 are crossing a bending edge, which makes up for the transition, between the U-leg 16 and the U-web 17. A bead 22 may have the form of a valley with a valley ground 23 extending at an obtuse angle alpha or beta respectively to the U-leg 16 and to the U-web 17, see Figure 5. Alpha and/ or beta may be between 120 and 160 degrees, preferably about 135 degrees.

[0027] The beads 22 may be formed by pressing. On each transition may be two or more or four or less beads 22.

[0028] The U-legs 16 have on their free ends a slot 24 with two slot edges 25, 26. The edges 25, 26 do merge at a slot end 27. Preferably, one of the slot edges 25, 26 has an outward projection 28 extending across to a plane in which a U- legs 16 do extend. The projection 28 is provided with a distance to the slot end 27. Preferably also with a distance to a free lower end of the U-leg 16. The projection 28 can also be bent out.

[0029] The slots 24 are to receive an axle 29 of the wheel 4. The projection 28 is of advantage to even better secure the axle 29 in the slot 24. For example, when combined e. g. with a nut 29a, see e. g. Fig. 2, for securing the axle 29 in the slot 24, the axle 29 cannot move beyond the projection 28 due to a form fit between the nut and the projection 28 even in case the nut 29a would not be fastened correctly.

[0030] The U-web 17 further has preferably a hook formation 30 on one of its edges between the U-legs 16. More preferably, there are two hook formations 30, 31. The book formations 30, 31 may have one or two hook noses 32, 33. The noses 32, 33 may be directed toward each other. The one or two hook formations 30, 31 may serve to secure at the fork 11 a separate housing part 34, see e. g. Fig. 17.

[0031] According to one possible embodiment, the fork 11 may be combined with a cable guiding and securing part 35. [0032] The cable guiding and securing part 35 is preferably separate from the fork 11 but combined with the fork 11. The part 35 may be screwed, clipped on or otherwise fastened to the fork 11. At the embodiment shown, a screw connection 35a is realized together with a further insert connection provided preferably only by one stud, e.g. received in a hole 35b of a leg of the fork 11. Preferably, therefore, by only one screw connection a reliable rigid joint of the part 35 to the fork 11 is given.

[0033] The part 35 has preferably an S-design. The part 35 may run along one of the two outer edges of the U-leg 16.

[0034] The arrangement with the part 35 does allow for a comparatively small design of the castor in direction of the axis x.

[0035] The part 35 can have one or more clamp parts 37 and a receiving section 38. A clamp part 37 may serve to clamp and hold the power cable 36 on the cable guiding and securing part 35.

[0036] The swivel castor 1 may have two sealing caps 39, 40, see Figures 2 and 10, 14 and 20. The sealing caps 39, 40 are preferably arranged inside to the fork 11 and in this respect especially inside to the U-legs 16. The sealing caps 39, 40 may be outside, also preferably outside to the fork 11, covered by an outer design cap 41, 42, see Figure 20. The sealing caps 39, 40 are extending essentially across to the axis x.

[0037] The sealing caps 39, 40 are turning with the wheel 4. In view of securing against media from outside, e.g.in case of washing the castor, a special sealing is provided for. A radial outer edge 43, see also Fig. 10, 11 and 14, of the sealing caps 39, 40 is preferably fastened to the treat part 5, further preferably by screws 43a, see also Fig. 9. Between an inner surface of a sealing cap 39, 40 and an outer surface of the tread part 5, a sealing string like O-ring 44 may be held. The treat part 5 and/ or the sealing caps 39, 40 may have a receiving groove 45 for the sealing string.

[0038] The sealing caps 39, 40 may have in a cross section in the region engaging with the treat part 5 a Y-structure. One Y-leg 47 may run at a right angle to the rotation axis x and a further Y-leg 46 may run parallel to the rotation axis x. The Y-leg 47 may lie against a radial surface of the treat part 5 and the Y-leg 47 may lie against an inner surface of the treat part 5 extending in the direction of the rotation axis x. A root part 47a of the Y-structure may be curved in said cross section, extending further outward in the direction of the axle x compared to both the Y-leg 46 and the Y-leg 47. One of the sealing caps 39, 40, preferably the sealing cap 39 with the teeth 63, see further below, may have radially outward to the second part 47a a further outward directed step configuration 124 on which the teeth 63 are formed.

[0039] Radially inside the sealing caps 39, 40 are sealed against the axle 29, which is stationary, see also Fig. 10 and 12. The axle 29 is first received in a respective opening of each of the sealing caps 39, 40 by an antifriction bearing such as a ball bearing 48, 49. An extension 50, 51 on the inner side of each of the sealing caps 39, 44 is preferably lying against an outer ring 52, 53 of the antifriction bearing, therefore with no relative movement to the outer ring 52, 53.

[0040] At the anti-friction bearings as well as the axle 29, the respective areas do have preferably different diameters. The axle 29 has in this respect different outer diameters and the anti-friction bearings do have respective different inner and outer diameters, matching with the outer diameters of the axle 29. In case of ball bearings 48, 49, the inner rings 54, 55 have inner diameters matching the said outer diameters. In the direction of the axle 29, outside to the anti-friction bearings, the sealing caps 39, 40 are structured in terms of a cavity 56, 57, open to the axle 29. The cavities 56, 57 do house a sealing element 58, 59, being in sliding contact to the axle 29. The greater outer diameter D of the axle 29 is preferably on the side of the sealing cap 39 having also the teeth 63, see below, for the rotational lock. The smaller diameter d of the axle 29 is preferably about one third or more, up to 60% smaller than the diameter D. An effective radial extension of the sealing cap 39 is therefore smaller than the respective extension of the sealing cap 40.

[0041] The part of the axle 29 having the greater diameter has preferably also a through opening 60, see Fig. 10 and 13 , extending in the direction of the rotation axis x, for the power cable 36. Preferably, the power cable 36 does have a sealing sleeve 61 for sealing the power cable 36 within the through opening. The sealing sleeve 61 may be one part with the power cable 36 or an extra part to the power cable 36.

[0042] The wheel 4, as mentioned, is rotationally lockable. The locking is reached by an interaction of an engagement part 62, see Figs. 2 and 16, 17 movable from radially outside into spaces between circumferentially arranged teeth 63 provided on the wheel. Preferably, the teeth 63 are provided on one of the sealing caps 39, 40. Also preferably, only one of the sealing caps, the sealing cap 39, does have the teeth. The sealing cap 39 is provided on the side of the axle 29 which has the greater diameter. Therefore, preferably, also only one engagement part 63 is provided for.

[0043] One of the sealing caps 39, 40 does also preferably provide a space for a part, arranged on an inner side of the sealing cap 39, 40. Also the part is thereby protected against media from outside. The sealing cap 39, 40 providing the space for the part is preferably different from the sealing cap 39, 40 having the teeth 63.

[0044] The swivel castor 1 does have in its upper part the already addressed mounting stem 7. As is further evident e.g. from Figure 17, within the mounting stem 7 is received a push rod 65. The push rod 65 can be actuated by means of a control cam 66. In other embodiments also an actuation by an electrical motor might be realized. The control cam can be actuated, as it is shown e.g. in Figure 1, by a foot pedal 67.

[0045] The push rod 65 can be biased into an uppermost position by means of a spring 68. The spring 68 can be supported on the one hand on a sleeve 69 of the connector stem 7 and on the other hand on the push rod 65, e. g. on a screw connected application part 70.

[0046] The push rod 65 may take three different positions. A first position, see Fig. 17 a, is for directional lock, the second position, see Fig. 17b, for total lock and the third position, Fig. 17, a neutral position, for a free state of the castor.

[0047] The push rod 65 has a lock protrusion 71 which is by axial movement of the push rod 65 to move in and out of the opening 18b of the fork 11. When the lock protrusion 71 is received in the opening 18b, a directional lock is given.

[0048] For reaching the total lock, the push rod 65 is to move further downwards compared to figure 17, see Fig. 17b.

[0049] The rotational lock of the wheel 4 as already mentioned is given once the engagement part 62 is moved into spaces between circumferentially arranged teeth 63 provided on the wheel 4, see Fig. 17a. [0050] The engagement part 62 is arranged on a swivel part 72, see especially Fig. 16, 16a and 16b. The swivel part 72 is fork-shaped, having a first and a second yoke part 73, 73a, and two legs 74, 75 which extend from opposite ends of the yoke parts 73, 73a. The extension of the legs 74, 75 is substantially across to the extension of the yoke parts 73, 73a. The swivel part 72 as such is fastened, e.g. screw fastened, to the fork 11 and preferably inside of the fork 11.

[0051] The yoke parts 73, 73a do extend in crossing manner over the wheel 4 above the tread part 5. Further, at least the yoke part 73 is crossing a linear prolongation of the push rod 65. Preferably, also the second yoke part 73a is arranged beneath the push rod and also preferably moved by the push rod, at least once the push rod is moving from the neutral to the total lock position. The yoke part 73 is moveable on a circular path, thereby actuated by the pushing rod 65 moving in a straight line. The yoke part 73 is movable relatively to the fork 11 about the axis z. A pivot bearing 112 of the yoke part 73 is preferably provided on a transition of the yoke part 73 to the leg 74.

[0052] The axis z extends across the axis x.

[0053] A free end 110 of the movable yoke part 73 extends preferably trough an opening 111 in the opposite leg 75, in which also the engagement part 62 is received, see Figures 16 through 16c. The end 110 is further preferably engaging, with a certain relative movement, a respective end of the engagement part 62. Further, the end 110 is engaged by a return spring 113, supported on the fork 11. The return spring 113 may be a thigh spring with one arm acting on the movable yoke part 73 and the other arm fastened to the fork 11, preferably fastened to the swivel part 72. A middle portion may run around a journal stud, preferably given by a part providing also the spring connection 35a between the part 35 and the fork 11. [0054] The engagement part 62 is further preferably resiliently arranged on the swivel part 72. The arrangement is preferably by of one or two bias springs 76, see Figs. 16 through 16c. The engagement part 62 can be movable on the swivel part 72 in a straight line. Further, the engagement part 62 can be biased into a most extended radial outward position by means of the return spring 113. The bias might be by an indirect contact. As to this, the return spring 113 may engage a free end 110 of the first yoke part 73 and the free end 110 may act on the engagement part 62. The free end 110 may go through an opening 111 in the engagement part 62 and can act on an upper rim of a slider 114. The slider 114 is further preferably received within the opening 111 of the engagement part 62. The engagement part 62 is slidably received within the swivel part 72, preferably by the intermediate of the already mentioned bias springs 76. The engagement part 62 is preferably slidably received in this respect between guide surfaces 115, 116 of the engagement part, provided for in the leg 75 of the swivel part. The free end 110 pulls in the directional lock and possibly also in the neutral position the engagement part 62 upward. In the total lock position, Figures 16a, 17b, the free end 110 is pushing on the engagement part 62. As to this, the free end 110 is acting on the slider 114, compressing the bias springs 76 and thereby moving the engagement part 62 such that it is received within the teeth 63. In case in a first instance the teeth of the engagement part 62 do block with the teeth of the engagement part 63, after a very small further movement of the wheel 4, the bias springs 76 serve to push them within the teeth 63. The bias springs 76, therefore, allow the engagement part 62 to move into a space or spaces between the teeth 63 even in case there is first a hindrance due to being pressed on an upper edge of such tooth 63.

[0055] The lock protrusion 71 is preferably on a plate part 77 of the push rod 65. The plate part 77 which is therefore moving with the push rod 65 is preferably used to detect the actual position of the push rod 65 and thereby to detect the actual condition of the swivel castor 1, whether the castor is in the total lock or in the rotational lock.

[0056] The detection means 78 is to ascertain the position of the push rod 65 by means of a contact element 79, see Fig. 18 and 19. The contact element 79 is always in direct contact to the plate part 77, preferably a lower surface 80 of the plate part 77. Preferably, the yoke part 73a is also moveable with respect to the legs 74, 75. Further preferably only in a vertical direction with respect to a use position of the castor. The yoke part 73a does have vertical yoke part legs 118, 119, received in yoke part legs fitting apertures 120, 121 of the respective leg 74, 75 of the swivel part 72. The yoke part 73b is by means of the yoke part legs 118, 119 for a limited amount vertically movable. By means of compression springs 117, see Figs. 16, 16a the yoke part legs 118, 119 are biased in an uppermost position. The yoke part legs may be catch fastened in the yoke part legs fitting apertures 120, 121, by means of a catch protrusion 124.

[0057] The contact element 79 has an engagement part 81which is steadily biased by an engagement spring 82 against said lower surface 80. The engagement part may go through a passing through opening 123 of the swivel part, preferably provided in the yoke part 73. The engagement part 81 therefore is moving together with the push rod 65 in case the pushrod 65 is moved to its different positions concerning directional lock, neutral position and total lock. Also preferably the engagement part 81 has one or two switch extensions 83, 84, see e. g. Fig. 19, which move therefore also together with the engagement part 81.

[0058] The switch extensions 83, 84 do actuate one or two electrical switches 85, 86. In one position of the engagement part 81, preferably the neutral position, the one or two electrical switches 85, 86 are not actuated. In the position corresponding to the directional lock, one of the electrical switches 85, 86 is actuated. In case also a total lock position is to ascertain, the further electrical switch 86, 85 is provided for and actuated upon respective movement of the engagement part 81 in a direction starting from the neutral position opposite to the direction concerning directional lock.

[0059] For establishing the total lock, the yoke part 73a is provided with a locking element 87. The locking element 87 has preferably locking ribs 88 for cooperating with respective counter locking ribs 89 provided for also on the push rod 65, preferably on an underside of the plate part 77. Due to the vertical movability of the yoke part 73a due to the springs 117, also the locking element 87 provides the possibility to find a secure lock in case there would be a first block between the respective locking partners.

[0060] On one side of the fork 11 the already mentioned housing part 34, which may house special parts of the castor, is arranged. The housing part 34 is also swivelling with the fork 11. The engagement part 81 is protruding through an opening in the housing part 34.

[0061] The connection part 12 is fixed to the connector stem 7 by means of a structural part 104, which might be part of the receiving housing 101.

[0062] The treat part 5, see Figures 10, 14 and 15, of the wheel 4 does have preferably in more detail a treat 95, which is combined with a ring part 96, radially inside to the treat 95. The ring part 96 is preferably a metallic part, more preferably a steel part.

[0063] Figure 20 shows in form of an explosion view the essential parts of the swivel castor 1. There is first the mounting stem 7 with the bearing 102 at its lower end, part of which is fixed with the connector stem 7 as such and the other part with the fork 11.

[0064] Received within the fork 11, in the upper part, below the U-web 17, is the swivel part 72.

Reference numerals

1 swivel castor 33 hook nose

2 hospital bed 34 separate housing part

4 wheel 35 cable guiding and securing

5 tread part part

7 mounting stem 35a screw connection

8 fitting aperture 35b hole

9 upper free end 36 power cable

10 lower end 37 clamp part

11 fork 38 receiving section

15 controller 39 sealing cap

16 U-leg 40 sealing cap

17 U-web 41 design cap

18 inner contour 42 design cap

18a hole 43 outer edge

19 outer contour 44 O-ring

20 bent out region 45 receiving groove

21 tube part 46 Y-leg

22 beads 47 Y-leg

23 valley ground 47a root part

24 slot 48 ball bearing

25 slot edge 49 ball bearing

26 slot edge 50 extension

27 slot end 51 extension

28 projection 52 outer ring

29 axle 53 outer ring

30 hook formation 54 inner ring

31 hook formation 55 inner ring

32 hook nose 56 cavity cavity 87 locking element sealing element 88 locking ribs sealing element 89 counter locking ribs through opening 95 tread sealing sleeve 96 ring part engagement part 99 battery teeth 100 electrical connection part push rod 104 connection cable control cam 105 connection sleeve foot pedal 106 further swivel castor spring 107 fixed castor sleeve part 108 fixed castor application part 110 free end lock protrusion 111 opening swivel part 112 pivot bearing first yoke part 113 return spring a second yoke part 114 slider leg 115 guide surface leg 116 guide surface bias spring 117 compression spring plate part 118 yoke part leg detection means 119 yoke part leg contact element 120 fitting aperture lower surface 121 fitting aperture engagement part 122 step configuration engagement spring 123 through opening switch extension 124 catch protrusion switch extension electrical switch D greater outer diameter electrical switch d smaller diameter x rotation axis y vertical axis z axis p plane

Claims

1. Swivel castor (1) comprising a wheel (4) and a fork (11), wherein the wheel (4) has an outer tread (5) and is rotatable received in the fork (11), the fork (11) having a generally U-form with two U-legs (16) and a U- web (17), the U-legs (16) and the U-web (17) being materially uniform, the fork (11) being a metal part build from a metal strip by punching in view of outer contour (19) and inner contour (18) and further by bending, the U- web (17) being materially uniform with the U-legs (16), wherein the U- web (17) has an area of smaller thickness (d) compared to the thickness (d') of the U-legs (16).

2. Swivel castor (1) according to claim 1, characterized in that the U-web (17) has a generally circular bent out region (20).

3. Swivel castor (1) according to claim 2, characterized in that the bent out region (20) is basis for a tube part (21), combined with the fork (11) at the bent out region (20).

4. Swivel castor (1) according to claim 3, characterized in that the tube part (21) is welded to the bent out region (20).

5. Swivel castor (1) according to one of the preceding claims, characterized in that the wheel (4) is breakable by positive lock by an engagement part (62) provided on the fork (11) and movable from radial outwards into spaces between teeth (63) circumferentially arranged on the wheel (4).

6. Swivel castor (1) according to claim 5, characterized in that the engagement part (81) is actuatable by a push rod (65) received within the mounting stem (7).

7. Swivel castor (1) according to claim 6, characterized in that the engagement part (62) is arranged on a swivel part (72) attached to the fork (11), the swivel part (72) being fork-shaped, having a first and a second yoke part (73a, 73b) and two legs (74, 75) extending from opposite ends of the yoke parts and substantially across to the yoke parts, with the first (73a) and the second yoke part (73b) extending over the wheel (4) above the tread (5) and crossing a linear prolongation of the actuation bolt, the first yoke part (73a) being movable on a circular path, actuated by the actuation bolt moving in a straight line.

8. Swivel castor (1) comprising a wheel, a fork (11) and a mounting stem (7), wherein the wheel (4) has a rotation axis (x) and is rotatable received in the fork (11), the fork (11) being swivelable attached to the mounting stem (7), the wheel being sealed by a first and second sealing cap (39, 40), extending essentially across to the rotation axis, the caps being on its outer circumference sealed to a ring part (96) of the wheel (4), the ring part (96) having on its outer side a tread (5), each of the sealing caps being sealed against the rotation axis (x) going through the sealing caps.

9. Swivel castor (1) according to claim 8, characterized in that the wheel (4) being rotationally lockable by an interaction of an engagement part (62) moveable from radially outside into spaces between circumferentially arranged teeth (63) provided on the wheel (3), the engagement part (62) being supported on the fork (11), one of the first and second sealing caps (39, 40) having the teeth (63) on its outside.

10. Swivel castor (1) according to claim 9, characterized in that the teeth (63) are provided on only one of the caps (39, 40).

11. Swivel castor (1) according to one of the claims 8 to 9, characterized in that that the sealing between the sealing cap (39, 40) and the rotation axis (x) is provided outside to a ball bearing (48, 49).

12. Swivel castor (1) comprising a wheel (4) and a fork (11), wherein the wheel (4) has an outer tread (5) and is rotatable received in the fork (11), the fork (11) having a generally U-form with two U-legs (16) and a U- web (17), the wheel being breakable by positive lock by an engagement part provided on the fork, wherein the engagement part is moveable from radial outwards into spaces between teeth circumferentially arranged on the wheel, the engagement part being actuable by an actuation bolt received within the mounting stem, the engagement part further being arranged on a swivel part attached to the fork, the swivel part being forkshaped, having a first and a second yoke part and two legs extending from opposite ends of the yoke parts and substantially across the yoke parts, with the yoke parts extending over the wheel above a thread of the wheel in the first yoke part crossing a linear prolongation of the actuation bolt, for the first yoke part moving on a circular path being actuated by the actuation bolt moving in a straight line.