GB2061718A - Castors - Google Patents

Abstract

A castor (10), especially a castor presettable for guidance, for supporting from a supporting surface, such as a floor, articles such as furniture, appliances, and machines, comprises a supporting component mounting a wheel axle supporting a wheel at each of its ends and having a more or less shield-like guard partially enclosing the wheels from above, and a locking device for inhibiting at least the rotary movement of the wheels, there being pivotally supported on the supporting component all adjustable lever with its control part extending through an opening in the guard, said control part effecting at least indirectly the adjustment of locking components. There are formed on the supporting component (13) two bearing cheeks (19, 20) extending in planes more or less parallel to the wheels (15, 16) and between the latter, said bearing cheeks forming between them an essentially slot-shaped free space (22) for the installation and movable support of the adjustable parts of the locking device. The bearing cheeks (19, 20) preferably also mount the wheel axle (17). The free space (22) formed between the bearing cheeks (19, 20) is preferably open in the downwards direction towards the support A, i.e. towards a supporting surface, in use of the castor (10). The supporting component (13) is preferably formed integrally with the shield-like guard (14, 14a) and the bearing cheeks (19, 20). Preferably, also the bearing cheeks (19, 20) extend from the inner surface of the guard (14) and the free space (22) extends more or less as far as the inner surface of the guard (14). <IMAGE>

Description

SPECIFICATION Improvements in or relating to castors This invention relates to a castor, especially a castor presettable for guidance (referred to herein as a "guide castor") for supporting from a supporting surface such as a floor, articles such as furniture, appliances, and machines, said castor comprising a supporting component mounting a wheel axle supporting a wheel at each of its ends and having a more or less shield-like guard partially enclosing the wheels from above, and a locking device for inhibiting at least the rotary movement of the wheels, there being pivotally supported on the supporting component an adjustable lever with its control part extending through an opening in the guard, said control part effecting at least indirectly the adjustment of locking components. Such a castor is described, for example, in Federal German Republic Gebrauchsmuster 76 12 547.This is concerned with a so-called twin guide castor, i.e. a guide castor with a wheel mounted on each end of its axle. In the known guide castor, the axle is sheathed in a sleeve-shaped bearing housing, which is disposed in a median plane of the supporting component on the respective inner ends of struts. These struts, with cavities therebetween, bring about a skeleton-like make-up of the central part of the supporting component. Within one of these cavities, there is below the shield-like guard partially surrounding the wheels at the upper side thereof, a bearing eye for mounting for swivelling movement an adjusting lever of a locking device.This adjusting lever protrudes with its actuating part outwards through an opening in the guard for the purpose ofthe actuation. Its part projecting inwardly beyond its swivel bearing at the bearing eye of the guard, is in the form of a control part and has at its end a drop-in pin projecting to both sides transversely to the swivelling plane; the outer ends of the drop-in pin, in the locking position, can at any given time enter between notched bars which are disposed in a revolving annular space of the more or less dish-shaped wheels. In this way the locking device is in a position to block the rotary motion of the wheels.In order to maintain the two-armed adjusting lever both in its release position and its locking position there are formed on the supporting component within the cavity whereat is the bearing eye, and between the guard and the bearing housing for the wheel axle, two notched holders associated with the end-positions of the adjusting lever. These notched holders consist of forked notches in which a central part of the drop-in pin can engage with positive locking due to shape.

The known castor with a locking device for the rotation of the wheels has advantageously a relatively simple construction. However, it appears doubtful whetherthe notched holders formed in one piece on the supporting component can continue to fulfil their function satisfactorily after long periods of operation; it must be taken into account that a piece of furniture or the like fitted with a locked castor is tempted to move, whereby the wheels exert a considerable stress on the drop-in pin, which can be directly detrimental to a sound functioning of the notched holders.By virtue oftheirdesign and construction, the notched holders must be subject to relatively rapid wear through frequent manipulation of the locking device, whereby the latter is not directly suitable for stopping the rotation of the wheels by frictional locking alone, as such stoppage by frictional locking presupposes the maintenance of sufficient brake pressure.

The known castor according to Federal German Republic Gebrauchsmuster76 12547 also reveals no possibility of achieving stoppages other than by stopping the rotation of the wheels. It should, moreover, be taken into consideration that for the operational movement of the parts of the locking device there is available only the space beneath the guard, and that this space is left between two struts arranged at an angle of about 100 .

The problem with which the invention is faced is the fundamental reconstruction and improvement of a castor, particularly a guide castor, of the general kind postulated at the beginning and known from the Federal German Republic Gebrauchsmuster76 12 547, in such a way that, with relatively simple and stable construction of its supporting component, it is suitable for the layout of the most varied locking devices in a particularly favourable way.

The invention solves this problem by forming on the supporting component two bearing cheeks extending in planes more or less parallel to the wheels and between the latter, said bearing cheeks forming between them an essentially slot-shaped free space for the installation and movable support of the adjustable parts of the locking device. Thus the castor according to the invention is particularly suitable for locking devices which are more comprehensive than that according to Federal German Republic Gebrauchsmuster76 12 547, particularly for such as have several parts adjustable relative to one another. There is a generous degree of space for movement of these adjustable parts between the bearing cheeks and the adjustable parts are at the same time laterally guided without more ado by the bearing cheeks extending in more or less parallel planes.Due to this, for example, an articulated correlation of two parts of the locking device may be formed relatively easily, as lateral displacement of the parts relative to one another cannot take place.

Owing to the arrangement according to the invention of the two bearing cheeks, an exceptional stability of the supporting components is attained so that the latter and the parts of the locking device can reliably withstand heavy stresses. As the adjustable parts of the locking device are housed in the more or less slot-shaped free space, these parts need essentially only to have a disc-like section, while there is no need for, for example, a forked construction for enclosing parts of the supporting component by the adjustable parts of the locking device. This makes a substantial contribution with regard to simple construction with high operational reliability.

A particularly advantageous further development of the castor according to the invention consists in the bearing cheeks also mounting the wheel axle. In the case of such a castor, the stressed middle portion is composed as a whole of the bearing cheeks, taking several functions upon themselves, instead of a skeleton-like construction such as is the case in the castor according to Federal German Republic Geb rauchsmuster76 12547. Through the, as it were, doubled arrangement of the stressed middle portion in the form of the two bearing cheeks, what is achieved, besides the advantages related to the locking device, is that the supporting component, without it being necessary to increase the overall width axially in the direction of the wheel axle, can be shaped to be particularly stable, and that at this same time there is made available a considerable free space for the movement of the adjustable parts of the locking device.

Afurtheradvantageous development ofthe castor according to the invention consists in that the free space between the bearing cheeks is open towards the surface on which the castor is supported. The direct advantage of this measure is that the parts of the locking device can be very easily inserted or fitted into the supporting component from below, that is into the free space between the bearing cheeks.

Another advantage consists in that parts of the locking device may extend downwards to the surface on which the castor is supported. Advantages also arise in the manufacture of a castor in which this supporting component and bearing plates are integrally and materially associated, so that the entire supporting component may be made as a plastics or light-metal die-casting.The supporting component is therefore preferably designed with the shield-like guard and the bearing cheeks, i.e as an integral component, it being possible to form the bearing cheeks on the inner surface of the guard on the carrier and the free space preferably extending more or less up to the inner surface of the guard, whereby not only is a particularly stable construction of the supporting component achieved, but almost the whole space beneath the guard and surrounded thereby is available for the disposition and movement of adjustable parts of the locking device.

A castor developed with the features according to the invention, especially in combination with the features that the bearing cheeks also mount the wheel axle, and the free space formed between the bearing cheeks is open in the downwards direction towards the support, i.e. towards a supporting surface in use of the castor, is suitable in a particularly outstanding way for the disposition of locking devices of the most varied kinds.In contrast to the state of the art according to the Federal German Gebrauchsmuster 76 12547, the possibility should particularly be emphasised, of equipping the supporting component with multiple-part locking devices, despite its relatively simple make-up, the adjusting lever of such locking devices being brought into play to control at least a second locking lever having the locking parts. Due to this with a particularly compact type of construction, optimum locking forces, e.g. frictional braking forces, can be transmitted and maintained, if necessary by suitable leverage.Although it is obviously also possible with the castor according to the invention to provide locking parts directly on the adjusting lever, particularly advantageous further developments of the castor within the scope of the invention are concerned with the locking device comprising a locking lever articulated to the bearing cheeks for swivelling movement and having the locking parts, which locking lever is connected at least indirectly for movement to the adjusting lever, which is also articulated between the bearing cheeks.

Because of this the locking lever and the adjusting lever may be respectively arranged to swivel around a bearing spindle transversely bridging the bearing plates and extending parallel to the wheel axis, thus may be supported outside the wheel axle, whereas in another construction, the locking lever may be mounted on the wheel axle to swivel therearound.

The type of support selected will be determined by the specific requirements of a specific locking device.

Particularly advantage and appropriate developments of locking devices within the scope ofthe invention, and particularly ingenious and functional practical arrangements, are best demonstrated by the following detailed description of several exemplary embodiments with reference to the accompanying drawings, in which:: Fig. 1 shows a first castor, in a longitudinal section parallel to the wheel plane, with a locking device for arresting the rotation of the wheels and the swivelling movement of the castor, in the release position of the locking device; Fig. 2 is a view corresponding to Fig. 1, but with the locking device in the locking position, Fig. 3 is a section according to the section line Ill-Ill in Fig. 2; Fig. 4 shows a second castor, in a section corresponding to that of Fig. 1, with a locking device the lever of which is connected with the adjusting lever by the arm, the locking device being in the release position; Fig. 5 is a view of the castor corresponding to Fig.

4, with the locking device in its locking position; Fig. 6 shows a third castor, in longitudinal section, the locking component of which co-operates with a circumferential toothing on the supporting journal of the castor, the locking component being in the release position; Fig. 7 shows the castor in Fig. 6, in a corresponding view, but with the locking device in the locking position; Fig. 8 is a sectional view according to the section line VIII-VIII in Fig. 7; Fig. 9 shows a castor in accordance with a fourth embodiment of the invention, with the locking device in the release position; Fig. 10 shows the castor of Fig. 9, with the braking device in the locking position; Fig. 11 is a section along the section line Xl-Xl in Fig. 9; ; Fig. 12 is a sectional view of a detail in Fig. 11, namely of the locking lever used in the castor accord ingtoFigs.9to 11; Fig. 13 is a side view of the locking lever in Fig. 12; Fig. 14 is a plan view of the locking lever; Fig. 15 shows a castor, which is presettable for guidance, in accordance with the fifth embodiment of the invention, the locking device being in the release position; Fig. 16 is a view corresponding to Fig. 15 with the locking device in the locking position; Fig. 17 shows a castor, partly in section in accordance with a sixth embodiment of the invention, the locking device constructed as a direction setter; Fig. 18 is a plan view of the castor in Fig. 17, according to the section line XVIII-XVIII;; Fig. 19 a view corresponding to Fig. 17, with the direction setter in the locking position; Fig. 20 shows a castor in accordance with a seventh embodiment of the invention, with a locking lever which can be maintained stationary on the floor level and is shown in full lines in the release position and in dotted lines in the locking position; Fig. 21 shows a castor modified in comparison to that in Fig. 20, with the locking device in the release position; Fig. 22 shows the castor of Fig. with the locking device in the locking position; Fig. 23 is a section along the line XXIII-XXIII in Fig.

21; Fig. 24 shows a castor in accordance with a further embodiment of the invention, with the locking device in the release position; Fig. 25 shows the castor of Fig. 24, with the locking device in the locking position; Fig. 26 shows a modified castor, very similar to that of Figs. 24 and 25, with the locking device in the release position; Fig. 27 is a section along the line XXVII-XXVII in Fig.26; Fig. 28 shows a further development of the castor of Figs. 26 and 27, with the locking device in the release position; Fig. 29 is a section through the castor of Fig. 28, along the line XXIX-XXIX in Fig. 28; Fig. 30 is a side view solely of the locking lever used in the castor of Figs. 28 and 29; Fig. 31 is a front elevation of the locking lever of Fig. 30;; and Fig. 32 is a plan view of the locking lever of Figs. 30 and 31.

The castor 10 shown in Figs. 1 to 3 is designed as a castor presettable for guidance (hereinafter called a "guide castor"), the supporting component 13 being swivellable about the vertical longitudinal axis of a supporting journal 11, which is rigidly connected to a plate 12 attachable by screwing on to furniture, apparatus or the like. The supporting component 13, which may be of plastics material or a metal diecasting, is substantially hood-shaped, and has a guard 14, which overlaps two wheels 15 and 16 widthwise (Fig. 3) and across substantially the upper half of their circumference (Figs. 1 and 2).The part 13 of the guard 14, 14a is conformed to the curved shape of the wheels 15, 16 at that place, while the part 14a of the guard 14, 14a has a substantially vertical shape in the portion in front of the castor 10.

The wheels 15, 16 are set at the ends of a wheel axle 17, which is hollow in this embodiment, and are held in position by flangings of the axle. The ends of the axle are covered by blind caps 18 (Fig. 3) inserted into concentric bores in the wheels 15, 16. The wheel axle 17 is supported in two bearing cheeks 19 and 20 each of which is tied at its upper end at the respective position 21 (Fig. 3) to the part 14 of the shieldlike guard 14, 14a and is integrally connected with the guard 14, 14a.

The bearing cheeks 19 and 20 are formed substantially in the shape of legs and extend vertically and parallel to one another and thus leave between them a free space 22 which is somewhat slot-shaped. This is open downwards towards the surface A on which the castor 10 rests. The bearing cheeks preferably extend functionally in the region below the part 14 of the guard 14, 14a, i.e. at the trailing side of the castor on the right-hand side of the supporting journal 11 relative to Figs. 1 and 2.

In addition to the mounting of the wheel axle 17 in coaxial bores 23, the bearing cheeks 19 and 20 serve to encase and swivellably mount movable parts of a locking device. This is explained in particular hereinafter.

It should, however, firstly be pointed out that the castors in accordance with the remaining exemplified embodiments and figures are of constructions basically comparable or analogous to the type already described. Inasmuch as like or similarlyoperating parts are illustrated in the other exemplary embodiments, these are provided with reference numerals in which the reference numerals heretofore used are again to be found. For example, for facility of comprehension, the supporting component 13 will be designated in another specific embodiment, for example, with 213. The same also applies to comparable parts of the various locking devices.

The present locking device comprises a locking lever 24 which extends substantially horizontally and is movably supported substantially centrally by means of a riveted swivel axle 25 between the bearing cheeks 19 and 20. With reference to Figs. 1 and 2, there are formed on the locking lever 24 two arms, of which that pointing to the right is an actuating arm 26, and that pointing to the left towards the supporting journal 11 being a locking arm 27.

Also movably supported on an axle 28 between the bearing cheeks 19 and 20 is an adjusting lever 29.

This has an actuating part formed oftwo arms 30 and 31, and a control part consisting of a noseshaped cam 32. The cam 32 co-operates by positive pressure alone with the actuating arm 26 of the locking lever 24. In the final positions of the locking device, the cam 32 engages in hollows 33 and 34 provided in the locking lever 24. The actuating part (arms 30 and 31) of adjusting lever 29 can protrude through an opening 35 in the cover 14. In the release position, the depressed arm 31 is lodged with its outer surface flush in a depression 36 in the part 14 of the guard (of Fig. 1). In this position the arm 30 is available for the purpose of actuation, e.g. by the foot of the operator, in the direction of the support surface A. If the adjusting lever 29, in accordance with Fig. 2, is in a position conforming to the blocking position of the locking device, the arm 31 has been lifted out of the depression 36 and can thus be returned into the depression 36, e.g. by means of foot actuation.

The guide castor illustrated in Figs. 1 to 3 has a so-called "total immobiliser" as locking device. This means that both the rotary motion of the wheels 15, 16 and the swivelling movement of the supporting component 13 around the vertical longitudinal medial axis of carrier pin 11 can be blocked or stopped. Forthefirst-named purpose, the locking arm 27 of the locking lever 24 has lobes 37 projecting to both sides parallel to the wheel axis 17, both of said lobes 37 being provided with a friction-enhancing covering 38 which is preferably resilient. The outer surface 388 (Fig. 1) of the covering 38 serves as a brake surface, and for positive friction contact against a peripheral surface 39 facing the wheel axle 17 of the respective wheel 15 or 16.In addition to the wheel brake formed by the lobes 37 with their coverings 38, the castor 10 also has a device blocking the swivel movement, to which end a toothing 47, substantially annular in shape, is arranged on the underside of the supporting journal 11, there being engageable with said toothing 47 in the locking position (Fig. 2) a tooth arrangement 41 which is made on the upper side of the locking arm 27 of the locking lever 24. This tooth arrangement 41 need have only one tooth; in the embodiment, as is illustrated particularly in Fig. 1, it has two teeth which engage in a substantially diametral correlation in the toothing 40 on the underside of the supporting journal 11.

If the adjusting lever 29 is moved by actuation of its arm 30 out of the position in Fig. 1 into that shown in Fig. 2, the cam 32 acting as an operating part in passing over from the hollow 33 into the hollow 34 of the actuating arm 26 of the locking lever 24, presses the latter around clockwise, so that both the wheel brake (37,38,39) and the swivel block (40,41) simultaneously come into engagement. In order that the wheel brake (37,38,39) remains effective even for long periods of time, the resilient and, as it were, self-restoring friction covering 38 is very advantage ous. The tooth arrangement 40,41 could also be so designed that it certainly becomes operative with a small tooth overlap and simultaneously applied wheel brake, so that, in the course of wear of the wheel brake, a continuing blocking engagement is possible.

Moreover, the locking lever 24 is constantly under the influence of a compression spring 42, which is inserted into a pocket 43 in a sleeve 44, which is an integral part of the supporting component 13. With its lower end, the compression spring 42 presses on a top edge of the locking arm 27 of the locking lever 24, said top edge being situated to the left of the axle 25, whereby the locking lever 24 is loaded in the direction of its disengaged position, so that the cam 32 of the adjusting lever 29 may continually have a positive pressure contact in the hollows 33 and 34.

Instead of the compression spring 42, a tension spring could be arranged on the actuating arm 26.

The exemplified embodiment explained with reference to Figs. 1 to 3 has in particular the advantage of a very simple design, enabling assembly thereof to be dealt with easily and accordingly is particularly suitable for cost-effective quantity production. With respect to assembly, it should be pointed out that the free space 22 between the bearing cheeks 19 and 20 is fully accessible from below, and also that the bounding edges (Fig. 1 and 2) of the bearing cheeks 19 and 20, extending substantially vertically in the exemplary embodiment, have no connection with one another. In this way the locking lever 24, which is of considerable overall length, can be introduced from below between the bearing cheeks 19 and 20 into the designated position, and pivoting thereof through the axle 25 can be taken care of when the wheels 15 and 16 are not yet mounted.The adjusting lever 29 can be introduced through the opening 35 from above the guard 14 with its control part (cam 32) foremost and then supported by the axle 28.

The castor 110 in accordance with Figs. 4 and 5, with regard to the locking device, has the same function and moreoever, fundamentally the same assembly. Accordingly, compared with the construction according to Figs. 1 and 2, there have been selected for similar or similarly-acting components reference numerals which have been increased by 100.

Differing from the castor in accordance with Figs. 1 to 3, in this case the actuating arm 126 of the locking lever 124 and the control part 132 of the adjusting lever 129 are not in clear positive pressure contact with one another; rather, there is arranged between them a guide lever 145 which is articulated through a pivot pin 146 with the actuating arm 126 and through a second pivot pin 147 with the control part 132 of the adjusting lever 129. The essentially lamellarflat guide lever 145 is situated in slots or pockets 148, 149 of the actuating arm 126 and of the control part 132.

The interposition of the guide lever 145 between locking lever 124 and adjusting lever 129, apart from the advantage of propitious potentials of a lever arm system and thus more effective transformation of the actuating force into locking force, has the advantage of reduced wear in relation to pivoting through direct pressure. Also, with the help of a guide lever 145, the swivel movements of the adjusting lever 129 and the locking lever 124 may be advantageously harmonized, which may for example be advantageous if it is desired to produce only a small adjusting path for the locking lever 124 along with a large adjusting path for the adjusting lever 129, which is favourable for operation.As moreover, the illustration of Figs. 4 and 5 shows, a toggle joint arrangement is provided by means of the guide lever 145 with the axle 147 as a toggle joint which is disposed between the pin 146 at the locking lever end, and the pin 128 at the adjusting lever side. In the locking position (Figs. 5), the toggle join 147 is in a position slightly beyond dead centre, which position, as may be seen, is secured by butting of the control part 132 against the obliquely-extending upper edge of the actuating arm 126. In this way there is formed a stable locking position which can in no way be removed by the compression spring 142, guaranteeing the freedom to vibrate of the lever arrangement.

A section through the guide castor according to Figs. 4 and 5 comparable with Fig. 3 of the first embodiment, could be imagined to be analogous. It need only be pointed out that the pivot axles 146 and 147 should not be articulated to the bearing cheek 119 and to the second bearing cheek 120.

A castor 120 in accordance with a third exemplary embodiment illustrated in Figs. 6 to 8, also constructed as a guide castor, has a few modifications in comparison with the two castors first described, though the locking action remains the same, i.e. that of total imobilisation. The supporting journal 211 is hollow cylindrical, whereby, as a result of the central bore, a castor fitted therewith could also be fixed from below by fixing means inserted thereth rough and upwards into the furniture or the like without being shown on the plate 212 attached by screwing to the furniture or the like. In this embodiment, the toothing 240 consists of a circumferential toothing, arranged on the outer surface in the lower region of the supporting journal 211, and in which a tooth as tooth arrangement 241 of the locking lever 224 can engage.

In order to reduce weight, the locking lever is provided with some openings, and is thereby skeletonlike in form. Contrary to the two-armed tipping levers of the two constructions first described, this lever 224 is to be conceived as a kind of swing lever, which is supported by means of the axle 225 at an end between the bearing cheeks 219 and 220. It is, therefore, not logically possible to differentiate between an actuating arm and a blocking arm.Similarly as in the case of the first exemplary embodiment in accordance with Figs. 1 to 3, the contacting of the locking lever 234 takes place through the adjusting lever 229 by way of a cam arranged on the latter as a control part 232 which acts upon the locking lever 224 by positive pressure, and in the locking position (Fig. 7) of the locking device, engages snugly in a hollow 233 (Fig. 6) in the locking lever 224. The spring enabling full interaction and preventing noise due to shatter is formed in this case as a coil or torsion spring 242, and is supported on the wheel axle 217.One turn end of the spring is lodged in an engagement gap 243 the locking lever 224, and embraces hooklikewith its otherturn and an edge, facing the rear wall of the guard part 214a, of one of the two bearing cheeks, in this case the bearing cheek 220. It should, moreover, be noted that because of the coincidence of the bearing cheeks 219 and 220 and the local coincidence thereof with the locking lever end in question, in views such as Figs. 6 and 7, the impression could be given that the arm end in question is turned around one edge of the bearing cheek 219. Of course, Fig. 8 enables clear understanding of the construction.

Unlike the exemplary embodiments heretofore described, the lobes 237 have a continuous outer surface which is covered over its full width by a coating 238. (Fig. 8).

It is considered as an advantage of the construction according to Figs. 6 to 8, that a relatively large swivelling displacement of the adjusting lever 229 leads to a relatively short swivelling movement of the locking lever 224.

The fourth exemplary embodiment particularly illustrated in Figs. to 14 also shows a castor 310 constructed as a guide castor with total immobilisation. Its supporting journal 311 indeed also consists of a pin rotatably carried in the supporting component 313, said pin is made slimmer and has no tooth construction at all. However, it is brought into play to arrest the swivel lability of the castor, for which pur- pose the locking lever 324 has laterally a cam 341 which in the locking position of the locking device is pressed with its front face forcibly against the surface 340 of the supporting journal 311. The sleeve 344 surrounding the supporting journal 311 and formed on the supporting component 313 has a window-like opening 344a enabling the supporting journal 311 to be gripped therethrough.

The compression spring 342 loading the locking lever 324 in the release position is supported against the outer surface of the sleeve-shaped section 344 and is mounted in a bore-like recess 343 in the locking lever 324.

The actuation of locking lever 324, which in this embodiment also may be classified as a two-armed rocker lever, takes place with this embodiment purely by positive pressure through a cam 332 made on the adjusting lever 329, said cam 332 in the release position catching in a small indent 333 in the locking lever 324 (Fig. 9), but being again removable therefrom.

Deviating from to the previous embodiments once more, the locking lever 324 is furnished in many respects with special features. Afirstfeature concerns its support on the bearing cheeks 319 and 320.

Indeed, no physical spindle or axle is provided for its support but the swivel axis 325 is formed by two pins 350 situated laterally on the locking lever 324 and pointing upwards, and which are supported in downwardly-opening bushings 351 which are formed on the inner sides of the two bearing cheeks 319 and 320. The range of contact of the pins 350 in the bushings 325 forms a hinge bearing with a free axis. In orderthatthe bearing parts are held together, the locking lever 324 has a slot-shaped opening 352, enabling same to be both supported and guided on the wheel axle 317. The opening 352, has a curved shape in conformity with its swivel spacing from bearing 350/351,so that during the relatively slight swivel movement of the locking lever 324, substantially the same bearing pressure is always maintained.

A further feature of the locking lever 324, best seen from Figs. 12 to 14, in which the locking lever 324 is shown alone, is that the lever has a W-shaped form in elevation and in longitudinal section; the outer limbs form annular brackets 353, which extend into the interior space of the dish-shaped wheels, as Fig.

11 shows. The external surfaces of the annular brackets 353, in the release position in accordance with Fig. 9 and Fig. 11, leave between themselves and the inner surface 339 of each of the wheels 315 and 316 a revolving annular slot which is substantially uniformly narrow throughout. For that reason the annular brackets, which are preferably formed integral with the locking lever 324, serve the purpose of excluding dust and in particular threads. At the same time however, they serve in a particularly advantageous manner as a wheel brake, as can be easily seen by comparison of Fig. 9 (release position) with Fig. 10 (locking position).The annular brackets 353, are swivelled relative to the wheel axle 317 of course when the locking lever 324 swivels anticlockwise, so that a braking zone results from application of the outer surfaces of the annular brackets 353 against the inner surfaces 339 of the wheels 315 and 316, said braking zone being denoted by the reference numeral 354 in Fig. 10. The reference numeral 355 denotes reinforcing ribs of arcuate shape which ensure the stability of the multiple-part (but preferably in one piece) locking lever 324.

The particular advantage of this version of castor is seen especially in the locking lever 324, which has a plurality of functions and can easily be manufactured by injection moulding, e.g. from plastics. The supporting component 313 is no more expensive than the supporting components hereinbefore described.

The castor 410 according to Figs. 15 and 16, simi marly to the construction according to Figs. 4 and 5, includes a guide lever445 between locking lever 424 and adjusting lever 429, forming a toggle joint arrangement 446,447 and 428 with the toggle joint 447. The locking lever 424 is directed more or less vertically, and has at its lower end the wheel brake with the lobes 437 and the coating 438.

It is supported more or less centrally on the guide lever 445, indeed to a certain extent "floatingly", as this construction does not include a wholly tangible swivel bearing, such as would be formed for example by a pin. The locking lever 424 is guided on the wheel axle 417, by a slot-shaped recess 456 arranged in the lever 424 towards its lower ends, said recess being open at one end in order to simplify assembly.

On the side of the wheel axle 417 remote from the pivot axle 446, there is supported a compression spring 442, and further above there is an arm with, on its end, a tooth consisting of at least one tooth 441. This upper arm 457 passes through an opening 458 in the upper cover 414, and can be brought into engagement with a circumferential toothed rim 440 which is provided on the plate 412 attachable by securing to the furniture or the like. In the release position according to Fig. 15, which is maintained by the action of the compression spring 442, the locking lever 424 is supported within the curved shape of the slot 456 against the wheel axle 417 and with its upper arm 457 against a stop 459 which is formed by an edge of the opening 458.The particular advantage of this construction is seen, along with its simple structure especially in that, in order to arrest the swivelling movement of the guide castor, a toothing which is simple and cheap to produce may be provided on the plate attachable by screwing, or on a comparable part of the furniture. The locking position is maintained with minimum wear by the toggle joint arrangement. Moreover, the specific support of the locking lever 424 offers the advantage of an automatic adjustment of the wheel brake 438/439, because the locking lever can still carry out certain swivelling movements in the clockwise direction around the axle 446, even in the locking position (Fig. 16).

In the specific embodiment represented in Figs. 17 to 19, the two-armed locking lever 524 has no wheel braking function; it is provided in this instance as a directional stabiliser, as is required, for example on hospital beds for moving the beds in the direction of their lengths in a straight line. The reference F in this case denotes the more or less tubular foot of a bed, in the cavity of which foot the elongated supporting journal 511 is inserted and is secured in position by a screw S. Non-rotatably connected with the supporting journal 511 is an annular plate P, which has notches 540 at diametrically opposite positions.

These notches 540 are provided for alternative engagement of the locking arm 527 of the locking lever 524. In the exemplary embodiment, a special entering tooth 541 is formed. In this exemplary embodiment the locking lever 524 is located in the locking direction by a compression spring 542, which direction, however, in the release position of the adjusting lever 529, cannot be inadvertently taken, because in such position there is a positive pressure support between the cam-shaped control part 532 of the adjusting lever 529 and the actuating arm 526 of the locking lever 524. - This construction is characterised by a surprisingly simple structure and simple components, and by the possibility of using a simply-designed plate P as an engagement member rigid with the furniture.

In the construction according to Fig. 20, the castor 610 can be completely immobilised, that is both the rotary motion of the wheels and the swivelling movement of the supporting component around the supporting journal may be locked in this construction. This takes place through the locking lever 624, though without physical contact thereof with the wheel 615 or with the other wheel 616. The locking lever 624 is formed in such a way that the foot arranged at the end of the lever 624 most remote from the swivelling axis 625 can be placed by the adjusting lever 629, the foot being provided with a coating 638 which is preferably elastic and enhances static friction.As is evident, in particular with the aid of the chain-dotted lines which represent the locking position, the foot in the locking position with its layer 638, is located more or less vertically below the supporting journal 611, so that there cannot be transmitted any moments of rotation which could lead to swivelling of the supporting component 613. The placement force of the foot is preferably so strong that the wheel 615 is easily raised from the support surface A. However, even when this is not the case, a stoppage ofthe rotary motion ofthe wheels occurs because the frictional force which the coating 638 produces on the support surface A makes travelling of the funiture or the like fitted with this castor 610 no longer possible without more ado. The oblong hole 652 within the locking lever 624 need not be adapted in its width to the diameter of the wheel axis 617, as in this case guidance is not necessary and the locking lever 624 is fully supported on the swivel axle 625.

The swivelling action of the locking lever 624 takes place against the action of the return spring 642 purely by positive pressure via the cam-shaped control part 632 of the adjusting lever 629. The arrangement should also be such that -- comparable with other approaches already described -- a guide lever would be arranged between adjusting lever 629 and locking lever 624.

The structure of the castor710 according to Figs.

21 to 23 differs from that according to Fig. 20 firstly by the arrangement of a guide lever 745 which is connected through articulations at the bearing axles 746 and 747 with the locking lever 724 on the one hand and the adjusting lever 729 on the other hand.

The toggle joint is formed by the axles 747, as can be seen especially in Fig. 22.

In contrast to the construction according to Fig. 20, the locking lever 724 in this case is supported on the wheel axle 717 and is pivotal therearound. The lever 724, like the lever 624, is constructed as a tipping lever, and therefore has essentially only one arm.

The return force is taken care of in this case by expanding spring 742, shaped more or less like a hairpin which is merely inserted into a pocket 743 at the underside of the guard 714. In the construction according to Figs. 21 to 23, a positive pressure contacting of the control part 732 with the locking lever 724, somewhat similar to that of the castor 610 in Fig. 20, could be used, with omission of the guide lever 745.

The advantage of the construction according to Fig. 20 consists essentially in the small number of components, while the castor 710 according to Figs.

21 to 23 is distinguished above all by lesser wear as a result of the guide lever 745, and the supporting of the locking lever is therefore very simple, as the wheel axle 717 is called upon for this purpose.

The castor 810 according to Figs. 24 and 25 is very similar with regard to the support ofthe locking lever 824, to the castor 610 according to Fig. 20, while the articulation of the locking lever 824 to the adjusting lever 829 is similarto that of the castor 710 in Figs. 21 to 23.

Unlike the two constructions of Fig. 20 and Figs. 21 to 23, the castor 810 according to Figs. 24 and 25 is provided in addition with a special wheel brake in the form of two lobes 837, which project laterally from the locking lever 824, and, in a way already described in more detail hereinbefore act with positive friction on the inner circumference 839 of the wheel 815 and also that of the wheel 816 (not shown). The castor 810 of this embodiment provides for an intensified braking of the wheels in relation to the castors 610 and 710, and can therefore be particularly recommended for different operating conditions.

The castor 810' shown in Figs. 26 and 27 is almost identical with the castor 810 of the exemplary embodiment illustrated in Figs. 24 and 25. The castor 810' also has a guide. lever 845' between locking lever 824' and adjusting lever 829', a wheel brake 837/839 also being provided. Differently formed, however, are the articulated arrangement of the locking lever 824' on the bearing cheeks 819 and 820 on the one hand, and the articulated connection of the guide lever 845' with the locking lever 824' and the adjust ing lever 829'.

The locking lever 824' forms a strong journal pin 825' which can be engaged by an insert slot 856 in the bearing plates 819,820 which are slid into position from below. It is therefore in this case a question of a pinless articulation. The studs situated in the lead-in slot 856, the angular extent of which is less than 180 , can be resiliently flexible, which is to be particularly recommended when the entire supporting component 813 is made of plastics material. But even in the case of a construction of, for example, die-cast light metal, such a construction may be of advantage if the locking lever 824' with its integral journal-pin 815' is made at least slightly resiliently flexible.

Similar joints exist between the pin 846' of the guide lever 845' and the bushing 848' in the locking lever 824' on the one hand, and correspondingly between the journal pin 847' of the guide lever 845' and the control part 832' of the adjusting lever 829'.

The arrangement in this case is in fact such that the insertion of the journal pin 846' into the bushing 848' is effected by fitting the former into the latter from a direction vertical to the drawing plane of Fig. 26. i.e.

is brought about by pre-assembly. On the other hand the journal pin 847' is clipped into the fork-shaped seating 849' of the control part 832' with a movement within the drawing plane of Fig. 26, this also being the procedure on insertion of the journal pin 825' through the insert slot 856 of the bearing cheeks 819,820.

The locking position is to be realised in more or less the same way as in the construction according to Fig. 25, as there are no fundamental differences in this respect. A final exemplary embodiment is shown by the castor 810" in Figs. 28 to 32. This differs from the castor 810' according to Figs. 26 and 27 in that the wheel brake in this case operates also acts by interlocking of shaped parts. For this purpose there is on each of laterally-projecting lobes 837' a toothed section 857, which in each case can cooperate with a circumferential toothing 858 which is formed on the inner circumference 839 of the respective wheel 815 or 816.

Moreover, the lobes 837' are completed to form revolving annular brackets 853, having the function ofthread exclusion. In order to avoid repetitions, reference should be made to the explanatory details with reference to the castor 310 according to Figs. 9 to 14, in the case of which there is a similar arrangement.

The description of the numerous exemplary embodiments makes clear how diversified in design could be the locking device on castors developed in accordance with the invention. It should be noted, however, that features of different constructions may also be combined with one another so that further logical possibilities arise. To mention a few examples; Instead of articulating the guide lever 145,445,745 and 845 by means of pin-shaped swivel axles 146, 147,446,447,746747 and 846,847 with the locking levers 124,424,724 and 824 and with the adjusting levers 129,429,729 and 829, a pinless arrangement could also be realized, as in the case of the castor 810" according to Figs. to 32.

The locking lever 624 of the castor 610 in Fig. 20 could be fitted with an additional wheel brake along the lines of the type provided in the case of the castor 810 or 810'. The locking lever 324 of the castor 310 (Figs. 9to 14) could have, instead ofthethrust pin 341, atoothing which would be engageable with a toothing arranged on a supporting journal, the supporting journal being formed along the lines of the supporting journals 11, 111, 211. Protection against entry of threads, provided in the form of a revolving annular collar, could readily be included also on the locking lever 724 of the castor 310 of the construction according to Figs. 21 to 23, this annular collar having no wheel braking function, as the locking lever 724 is mounted on the wheel axle 717.

In the case of the castors 210,610 and 810 of the exemplary embodiments according to Figs. 6 to 8, Fig. 20 and Figs. 24 and 25, the pin-shaped swivel axles 225,625 and 825, could be supplanted by an insertable arrangement in conformity with the castors 810' and 810" of the constructions according to Figs. 26 to 32.

The essential principle of all constructions described, or of those which could result from the interchange of individual features, is seen according to the invention in that the essential parts of each locking device are disposed compactly and ingeniously between the two bearing cheeks located on the supporting component, the bearing cheeks preferably also supporting the wheel axle, and the free space formed therebetween being open in a downward direction, and in the case of vertically extending boundary edges, also to the side, for the assembly and the necessary movement of the parts of the locking device.

Reference is made further to a particular bearing construction with the aid of Fig. 1. The supporting journal 11 is supported in the sleeve-shaped part 44 of the supporting component 13 by means of a ball bearing 9, and a sleeve bearing 8. In the case of the ball bearing 9, the balls 7 are housed between two races 6a, 6b stamped from sheet metal and are so arranged that, upon vertical loading of the supporting journal 11 toward the support surface A the ball bearing 9 becomes automatically free from play. The slide bearing 8 arranged in a zone therebelow comprises a bush 5 of a plastics material having good antifriction properties, preferably polytetrafluoroethylene. The PTFE bush is situated on a length of the supporting journal 11, the diameterd of which length is slightly less than the nominal diameter D.

Similarly-formed bearings are also represented in Figs. 2,4 to 7, 15 to 17 and 19. However, in order not to impair the clarity of these further Figures, the latter have not been provided at the corresponding parts with reference numerals similar to those in Fig.

Claims (45)

1. A castor, especially a castor presettable for guidance, for supporting from a supporting surface, such as a floor, articles such as furniture, appliances, and machines, said castor comprising a supporting component mounting a wheel axle supporting a wheel at each of its ends and having a more or less shield-like guard partially enclosing the wheels from above, and a locking device-for inhibiting at least the rotary movement of the wheels, there being pivotally supported on the supporting component an adjustable lever with its control part extending through an opening in the guard, said control part effecting at least indirectly the adjustment of locking components and there being formed on the supporting component two bearing cheeks extending in planes more or less parallel to the wheels and between the latter, said bearing cheeks forming between them an essentially slot-shaped free space for the installation and movable support of the adjustable parts of the locking device.

2. A castor according to claim 1, in which the bearing cheeks also mount the wheel axle.

3. A castor according to claim 1 or 2, in which the free space formed between the bearing cheeks is open in the downwards direction towards the support, i.e. towards a supporting surface, in use of The castor.

4. A castor according to any one of claims 1 to 3, in which the supporting component is formed integrally with the shield-like guard and the bearing cheeks.

5. A castor according to any one of claims 1 to 4, in which the bearing cheeks are integral with the guard and extend from inner surface of the latter and the free space extends more or less as far as the inner surface of the guard.

6. A castor according to claim 1, in which the locking device comprises a locking lever having lock ing means and articulated for swivelling movement to the bearing cheeks, said locking lever being at least indirectly coupled for movement to the adjust- .

ing lever likewise articulated between the bearing cheeks.

7. A castor according to claim 6, in which the locking lever and the adjusting lever are each mounted to swivel about a respective bearing axle transversely bridging the bearing cheeks and extending parallel to the wheel axle.

8. A castor according to claim 6 or 7, in which the locking lever is supported on the wheel axle to swivel about the latter.

9. A castor according to claim 6,7 or 8, in which the locking lever is articulated to a swivel bearing spaced from the wheel axle and has a slot-shaped opening with sides curved in conformity with the turning radius and by means of which it is guided on the wheel axle.

10. A castor according to any one of claims 6 to 9, in which the locking lever is a two-armed lever of which one arm is connected as an actuating arm with the control part of the adjusting lever and of which the other arm as a locking arm, has at least one locking part.

11. A castor according to any one of claims 6 to 10, in which the locking lever is a two-armed lever each of the arms of which has at least one locking part and the control part of the adjusting lever engages the locking lever at least indirectly in a region between the locking parts.

12. A castor according to claim 11, in which the locking lever is supported to be displaceable more or less at right angles to its length since it is supported on the wheel axle through a slot-shaped recess extending within one arm more or less at right angles to the aforesaid length to be displaceable to a limited extent, and its other arm in the release position is in contact with a stop at its end adjacent the supporting component.

13. A castor according to claim 12, in which the stop on the supporting component is formed by one edge of an opening provided in the guard.

14. A castor according to any one of claims 10 to 13, in which one arm of the locking lever has an arresting part inhibiting the swivelling movement of the castor and the other arm has an arresting part inhibiting the rotary movement of the wheels.

15. A castor according to claim 14, in which both the arresting part inhibiting the swivelling movement of the castor and the arresting part inhibiting the rotary movement of the wheels are arranged on the same arm of the locking lever.

16. A castor according to any one of claims 6 to 13, in which the locking lever is connected through a guide lever with the control parts of the adjusting lever, the guide lever forming a swivelling bearing with both the locking lever and the adjusting lever.

17. A castor according to claim 16, in which the articulation connecting the locking lever and the adjusting lever with one another, is thetoggle joint of a toggle lever arrangement,

18. A castor according to any one of claims 6 to 17, in which the locking lever is loaded at least indirectly by a spring supported or articulated at one end on or to the carrier, said spring pressing the locking lever in the direction of its locking or release position.

19. A castor according to claim 18, in which the spring is housed in the free space between the bearing cheeks.

20. A castor according to any one of claims 6 to 15, in which the locking lever has at least one cam, which may be brought into engagement with a part rigid with the article such as the article of furniture, the appliance or the machine.

21. A castor according to claim 20, in -which the locking arm is passed through an opening at its end adjacent the supporting component and may be brought into engagementwith a part rigid with the article such as the article of furniture, the appliance or the machine.

22. A castor according to any one of claims 10 to 21, in which the locking lever is provided with lobes which extend outwards transversely to the swivel plane of the locking lever and have arresting parts such as braking surfaces or stop cams, which can make contact with the insides of more or less dishshaped wheels.

23. A castor according to Claims 22, characterised in that the arresting parts on the lobes have a toothing which may be brought into contact with congruent toothings on the insides of the dishshaped wheels.

24. A castor according to any one of claims 10 to 23, in which the locking lever has a bearing surface area which, in the locking position, acts upon the surface of a supporting journal supporting the supporting component and fixed when the castor is in use to the article such as the article of furniture, the appliance or the machine.

25. A castor according to any one of claims 6 to 24, in which there are formed on the bearing cheeks bushings opening essentially towards the surface on which the castor is supported in use, the locking lever being braced with at least one journal pin against said bushings.

26. A castor according to claim 25 in which the bushings are formed on the inner sides of the bearing cheeks, the locking leverwith journal pin is braced against the bushing by positive pressure alone and the contact between journal pin and bushing is maintained by articulation of the locking lever on the wheel axle by means of a slot guide.

27. A castor according to claim 25, in which the bushings are formed in the region of the lower edges of the bearing cheeks.

28. A castor according to claim 27, in which the bushings partly surround the journal pins of the locking lever over an angular reach of more than 180 and leave a slide-in slot spanning an angular reach of less than 180 , which is preferably directed towards the surface on which the castor is supported in use.

29. A castor according to claim 28, in which the slide-in slot is limited by two resiliently flexible projections.

30. A castor according to claim 16 or 17, in which pinless articulation of the guide lever on the locking lever and on the adjusting lever is realised by the forming both on the locking lever and on the adjusting lever of a respective bushing spanning a circumferential reach of more than 180 , and the lengthwise insertion and/or transverse clipping thereinto of journal pins on the guide lever.

31. A castor according to any one of claims 6 to 30, in which the locking lever has, as a locking unit, a support leg which may be set up in use of the castor, on the support surface in the area beneath the swivel journal pin.

32. A castor according to any one of claims 6 to 31 in which the locking lever has a section part which projects outwardly below the lower edges of the bearing cheeks, and on which are formed revolving annular collars which extend outwards and project into the cavity formed by the dish-shaped wheels, with a small spacing from the inwardly-directed dish rims.

33. A castor according to claim 32, in which parts of the circumferential regions of the annular collars in the locking position of the locking lever also form braking areas contacting the inside of the dish rims.

34. A castor according to claim 32, in which a toothed zone is arranged over part of the external periphery ofthe annular collar and functions as an arresting part.

35. A castor, especially a castor presettable for guidance, substantially as herein before described with reference to Figs. 1 to 3 of the accompanying drawings.

36. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 4 and 5 of the accompanying drawings.

37. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 6 to 8 of the accompanying drawings.

38. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 9 to 14 of the accompanying drawings.

39. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 15 and 16 of the accompanying drawings.

40. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 17 to 19 of the accompanying drawings.

41. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Fig. 20 ofthe accompanying drawings.

42. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 21 to 23 of the accompanying drawings.

43. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 24 and 25 of the accompanying drawings.

44. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 26 and 27 of the accompanying drawings.

45. A castor, especially a castor presettable for guidance, substantially as hereinbefore described with reference to Figs. 28 to 32 of the accompanying drawings.