ANTISKID DEVICE

Abstract: An antiskid device for vehicles comprises an actuatable arm (2), a rigid spindle (5), which is arranged on the arm (2), and a rotatable antiskid-element-carrying roller (3) which is mounted on the spindle (5). The roller (3) can be set in various angular positions and should, in a working position, rotate in connection with a vehicle wheel (6). The spindle (5) is turnable about an axis (10) extending through the arm (2) and is provided with a locking means (8, 9, 14). The turning axis (10) of the spindle (5) and the axis of rotation (11) of the roller (3) make a constant angle ( alpha . The turning of the spindle (5) about the axis (10) is connected to the adjustment of the angular position of the roller (3).

Description: ANTISKID DEVICE Technical Field The present invention relates to an antiskid device for vehicles and more specifically to a device of the type as stated in the preamble to the accompanying claim 1. Description of the Prior Art Different types of antiskid devices are available on the market, most of which comprise a pivotable arm which, when actuated, presses a rotatable roller against a ve- hide wheel (the side of the tyre). The roller is fitted with antiskid elements, usually pieces of chain. When the roller is pressed against the vehicle wheel, it is caused to rotate and throws the antiskid elements outwards by centrifugal force. The antiskid elements will then be thrown in before the vehicle tyre and be pressed in between the vehicle tyre and the ground, whereby the friction between tyre and ground increases. The publica¬ tion CA-A-1,138,314 discloses such an antiskid device, in which chain pieces suspended from a roller are thrown in before a vehicle wheel when the roller is caused to ro¬ tate by frictional engagement with the vehicle wheel. The publication SE-B-466,539 discloses a further an¬ tiskid device, in which chain pieces carried by radial fingers of a rotatable member are thrown in between the wheel of a vehicle and the ground in the working posi¬ tion. In this special type of device, rotational drive does not occur by engagement with the tyre side, but the rotatable member is in this case driven only by the fric¬ tion between tyre and ground. The invention is also applicable to antiskid-element-carrying, rotatable mem¬ bers of this type. In devices of the above-mentioned type, the antiskid elements are caused to act between the tyre and the ground in that part of the cycle of rotation of the ro- tatable member in which the antiskid elements are thrown backwards. On the other hand, the antiskid elements should not touch the ground during that part of the cycle of rotation in which they are thrown forwards. Moreover, the antiskid-element-carrying, rotatable member must ro- tate at a distance from the ground. These three main con¬ ditions of the antiskid device usually lead to the rotat¬ ing member being placed in the working position so as to be inclined slightly downwards/outwards. When using such an antiskid device, it is also im- portant that the rotatable member provided with the anti¬ skid elements engages with the vehicle wheel exactly in the correct position. If the rotatable member is a roller, this should, in operation, rotate against the side of the tyre. In other antiskid devices, in which the antiskid elements are supported by fingers belonging to the rotatable member, this should, in operation, rotate in connection with the contact surface of the tyre and the ground. For these two different rotatable antiskid- element-carrying members, it has been found that the angle at which the member rotates in connection with the vehicle wheel relative to the plane of rotation of the vehicle wheel is decisive of the antiskid effect that can be achieved. Antiskid devices of the types, to which the inven- tion relates, are usually mounted at the rear axle of heavy vehicles. In such vehicles, there are great differ¬ ences in the appearance of the design of the mounting po¬ sition and the area of the rear axle. Therefore, the antiskid device must be adapted to each vehicle model. Further, the design and position of the rear axle have great tolerances in such vehicles. Prior art antiskid devices are, for reasons of strength, made of relatively thick materials which are bent and welded. Such materials and methods of manufac- ture make it difficult to achieve sufficient accuracy in respect of e.g. the setting angles. For these reasons, it is necessary to set the exactly correct height and angle between the rotatable member and the vehicle wheel in each individual mounting. DE-A-4,022,907 discloses an antiskid device, in which the adjustment of the relationship between the ro- tatable member or roller and the vehicle wheel in respect of height and angle is carried out by means of a ball- and-socket joint. The roller is mounted on a threaded bolt, whose threaded portion is enclosed by the ball-and- socket joint. The thread of the bolt permits vertical ad- justment of the roller while the ball-and-socket joint permits adjustment of the angle of the roller relative to the vehicle wheel. This prior art device has many degrees of freedom and thus suffers from the drawback that the adjustment that has been made in mounting is difficult to maintain. Above all, the angular adjustment of the ball-and-socket joint is sensitive to the jerks and tensile forces to which the roller is subjected when being taken into operation and during operation. The device is compara- tively complicated and consists of a plurality of compo¬ nents, which renders it expensive. Particularly the ball- and-socket-joint construction accumulates dirt, which is a great problem in the dirty, salt and moist environment which slippery winter roads constitute. This makes it rust easily, which may cause jamming and which impairs the function and makes it difficult to make exact fine adjustments later on. In a preferred embodiment of the above-mentioned de¬ vice, the ball of the ball-and-socket joint is made of plastic. The plastic material is deformed when, during mounting, the ball-and-socket joint is tensioned. This embodiment of the ball-and-socket joint certainly results in higher resistance to rust and angular changes, but since the ball is deformed during mounting, it will then be difficult to use if, for instance, after a change of tyre or a repair, the pre-set angle must be changed. It is also a complicated operation to set the suitable angu- lar position of the ball-and-socket joint, since the as¬ sembler must hold the roller steady in the desired posi¬ tion by one hand and simultaneously tighten a number of bolts by the other hand. In a well-tried solution of the construction of an¬ tiskid devices, the vertical adjustment of the rotatable member is carried out by means of distance members posi¬ tioned around a spindle on which said member is mounted. This construction has been found to allow a simple method for vertical adjustment and is less sensitive both to rust and mechanical influence as compared with the anti¬ skid devices whose functions of vertical adjustment are based on a thread. However, there is today no antiskid device having such a construction of the vertical ad- justment that permits adjustment of different angular positions of the rotatable member. Objects of the Invention One object of the present invention is to provide an antiskid device which obviates the above-mentioned draw¬ backs and enables simple adjustment of the angular posi¬ tion of the rotatable, antiskid-element-carrying member relative to the vehicle wheel. A further object of the invention is to provide an adjusting possibility having little sensitivity to ten¬ sile forces and jerks, thereby preventing a pre-set angu¬ lar position from being changed during actuation and dur¬ ing operation. A still further object of the invention is to pro- vide an antiskid device, in which it is easy to change a pre-set angle a very large number of times while main¬ taining the function of angular adjustment. A special object of the invention is that it should be possible to apply the function of angular adjustment to antiskid devices in which the vertical adjustment of the rotatable member is carried out by means of distance members. It is also an object of the invention to provide an adjusting device which is easy to manufacture and is formed of simple standard components. One more object of the invention is that the func- tion of angular adjustment should have the same good function, independently of the direction in which the arm, on which the rotatable member is mounted, extends in the working position. Summary of the Invention According to the invention, these and other objects, which will be apparent from the description below, are achieved by means of an antiskid device which is of the type described by way of introduction and which, in addi- tion, has the features stated in the characterising clause of the accompanying claims 1 and 12. Preferred em¬ bodiments of the invention are defined in the subordi¬ nated claims. In one aspect of the invention, an antiskid device for vehicles is provided, which comprises an actuatable arm, a rigid spindle attached to the arm, and a rotat¬ able, antiskid-element-carrying roller which is mounted on the spindle. The roller can be set in different an¬ gular positions and should, in a working position, rotate in connection with a vehicle wheel. The spindle is turn- able about an axis extending through the arm and is pro¬ vided with a locking means. The axis of spindle turning extending through the arm and the axis of rotation of the roller make a constant angle. The turning of the spindle about the axis is connected to the adjustment of the angular position of the roller. In another aspect of the invention, an antiskid de¬ vice for vehicles is provided, in which the spindle com¬ prises two portions, the first portion having, in the area of the attachment to the arm, an extent which essen¬ tially coincides with the predetermined axis, about which the spindle is turnable. The other portion has an extent which essentially coincides with the axis of rotation of the rotatable member. By means of an antiskid device of the invention, whose angular adjustment has few degrees of freedom, a more reliable adjustment is achieved. Moreover, the angu¬ lar adjustment is necessarily connected to a turning mo¬ tion, whereby a set angular position is maintained in spite of jerks and tensile forces. This means that no force affecting the rotatable member can change the set angular position by a rectilinear motion only. The ro¬ tatable member can be moved out of its position by a turning motion only. The connection between turning and angular position also confers the advantage that the adjustment of the angular position will be extremely simple. Consequently, the assembler does not have to hold the rotatable member steady when setting a new angle. The assembler may, after having set the desired angular position, let go of the rotatable member and his hands are free to lock this po- sition. No part of the device need be deformed for locking the set angular position, which makes it possible to change the angular position a countless number of times while maintaining the function. The possibilities of adjustment according to the in¬ vention are achieved by means of standard components and may advantageously be applied to antiskid devices, in which the vertical adjustment is carried out by means of distance washers, the antiskid device requiring no great space. These properties are important to allow mounting of the inventive antiskid device on small vehicles. A great advantage is that the adjusting device according to the invention can be mounted on existing antiskid devices, as well as on newly manufactured ones. The angular position of the rotatable member has the same possibilities of adjustment independently of the di- rection in which the arm, on which the member is mounted, extends in the working position. Brief Description of the Drawings The invention will now be described in more detail with reference to the accompanying drawings which illus¬ trate some non-restrictive embodiments. Fig. 1 shows an example of a prior art antiskid de¬ vice of the type to which the invention is applicable. Fig. 2 is a schematic view of a rotatable member be¬ longing to a device according to the invention. Figs 3-4 are two different side views of the ro¬ tatable member in different angular settings. Figs 5-6 are two different side views of the ro- tatable member in different angular settings according to Figs 3-4, the vertical setting being different. Figs 7 and 8 are side views, on a larger scale, of details of two preferred spindle attachments belonging to the device. Description of Embodiments of the Invention Fig. 1 illustrates a prior art antiskid device for vehicles in its working position. The device comprises a holder 1 which is adapted to be mounted at the rear axle of the vehicle and which has an arm 2, which is hingedly connected to the holder 1 and is actuatable between a working position and a resting position. On the arm 2, a rotatable member is mounted, here in the form of a roller 3, fitted with antiskid elements, here in the form of pieces of chain 4. The roller 3 is rotatably mounted on a spindle 5' which is attached to the arm 2. In the working position of the antiskid device, the roller 3 engages the side of a vehicle wheel 6 (the side of the tyre) and is thus caused to rotate. This implies that the pieces of chain 4 are thrown outwards by centrifugal force and in between the vehicle wheel 6 and the ground 13, thus pro¬ ducing the desired friction. Fig. 2 illustrates a device according to the inven¬ tion, in which a corresponding roller 3 engages the side of the vehicle wheel 6 at its inner side 7. For the sake of clarity, a plurality of components have been omitted in the Figure. The roller 3 is mounted on the spindle 5, which here is specially designed, and rotatable about an axis of rotation 11. In prior art manner, the roller 3 comprises a number of mountings 20, to which antiskid elements, for instance pieces of chain, are to be attach- ed as shown in Fig. 1. The spindle 5 is rigid and, at its attachment to the arm 2, turnable about a predetermined axis 10. In a certain position as set, the spindle 5 is locked by locking means which will be described in more detail below. A constant angle α forms between the axis 10 and the axis of rotation 11 of the roller 3. When the spindle 5 is turned for new adjustment, the axis of rotation 11 of the roller 3 will be turned about the axis 10. The angular position of the roller 3 in relation to the side of the wheel 6 will then be changed. The range, in which the angular position can be set, is dependent on the size of the constant angle α. The size of the angle α is selected according to the range one wants to cover and the desired accuracy of the adjustment. The intended possibility of adjustment is achieved in the range of 3- 20° for the constant angle α. Practical experiments have given excellent results in the angular range 5-10°, and it has been found that a particularly suitable value of the angle α is about 5°, which means that the roller 3 can be set in the range ± 5° (10° deviation). The spindle 5 is provided with a distance member generally designated 9 and comprising a number of dis¬ tance washers, and a clamping means in the form of a nut 8 on a thread. Moreover, the spindle 5 comprises an abut¬ ment in the form of a head 14. When the nut 8 is tight- ened, the spindle will be locked in position. By the dis¬ tance means 9, the roller is held at a predetermined dis¬ tance from the arm 2. The distance washers can be posi- tioned on an optional side of the roller 3 and, thus, de¬ termine the vertical adjustment thereof (see Figs 3-4 and 5-6, respectively). In Fig. 3, the roller 3 is shown separately, and it is apparent how the angular position of the roller 3 can be adjusted according to the invention. The constant angle α forms by the spindle 5 being slightly angled at its attachment to the arm 2. The spindle 5 is also pro¬ vided with a number of distance washers 9, the one 12 closest to the arm 2 being bevelled. The angle which forms between the opposite abutment surfaces of the dis¬ tance washer 12 is equal to said constant angle α. The distance washer 12 thus has a surface which is perpen¬ dicular to the axis of rotation 11 of the roller 3 and which constitutes a stable abutment surface for the re¬ maining distance washers. The distance washer 12 need not necessarily be bevelled, but can be made of a flexible material which is slightly deformed into an oblique shape when compressed (not shown). It may then have about the same function as if it were bevelled. If an angular spindle 5 is used, the desired adjustment can be achieved (for small angles α) without any bevelled distance washer 12, or with a distance washer which does not have the exact angle α between its opposite surfaces. To achieve a good function, i.e. simple handling and stable locking, it is however preferred that the distance washer 12 in operation has the angle α between its abutment surfaces. One extreme angular position of the roller 3 is in¬ dicated by full lines, whereas the other extreme angular position of the roller 3 is indicated by dash-dot lines. The roller 3 is shown in Figs 3-4 in a lower vertical ad¬ justment position in which all the distance washers are placed between the roller 3 and the arm 2, which here is located above the roller 3. Fig. 4 is a different side view, perpendicular to the one in Fig. 3, of the roller 3 and its attachment to the arm 2. However, the roller 3 is shown in two angular positions which differ from the one in Fig. 3. It is apparent that the roller 3, when being turned, will oc¬ cupy different angular positions relative to the arm 2. It is thus not necessary that the arm 2 extends in a cer- tain direction in relation to the vehicle wheel or the direction of travel of the vehicle. All angular adjust¬ ments within the range 2α can be provided independently of whether the arm 2 in the working position extends in the direction of travel of the vehicle, at right angles to this or in any direction therebetween. As a result, the inventive antiskid device can be mounted in different ways and on different vehicles without affecting the function of angular adjustment. Figs 5 and 6 differ from Figs 3 and 4 merely by the roller 3 being in its upper position of vertical adjust¬ ment (cf. Fig. 2) owing to the condition that all the distance washers, except the bevelled distance washer 12, are arranged below the roller 3. Fig. 7 shows a further embodiment of the spindle and its attachment. The possibilities of angular adjustment are in this case brought about by a straight spindle 5a, fitted with a head 14a, being turnable and inclined in a hole 15 in the arm 2. Since the hole 15 is of a diameter which is greater than the diameter of the spindle 5a and since the spindle 5a has two bevelled distance elements, here in the form of distance washers 12a, a constant angle α forms between the centre axis 11a of the spindle 5a, which at the same time is the axis of rotation of a rotatable member, and the axis 10 about which the spindle 5a, together with the distance washers 12a, can be turned. By a clamping member (not shown), together with a plurality of distance members and a rotatable member, clamping the spindle 5a, the angular adjustment can be locked. The diameter of the hole 15 need not be constant throughout, but the hole can advantageously also be coni¬ cal. A different, similar technique of providing a possi¬ bility of angular adjustment according to the invention (not shown) is to arrange a circular sleeve, which has an angle between the centre axis of its outer diameter and the centre axis of its inner diameter, turnable in a hole in the arm. A straight spindle is arranged in the hole of the sleeve and a constant angle according to the inven¬ tion forms between the centre axis and the axis about which the spindle, together with the sleeve, can be turned. Fig. 8 shows a further example how to bring about a possibility of angular adjustment according to the inven¬ tion. An angled spindle 5b has a threaded portion 16 ex¬ tending through a hole in the arm 2. On both sides of the arm 2, a nut 8b is screwed onto the thread. When the nuts 8b are moved apart, as shown in Fig. 8, the spindle 5b can be turned at its attachment to the arm 2. When the spindle 5b is clamped to the arm 2 by means of the nuts 8b, the set angular position is locked for that portion 17 of the spindle 5b which extends obliquely away from the arm 2 and on which the rotatable member is to be mounted. One of the nuts 8b could, of course, be replaced by a fixed abutment on the spindle 5b, or by the hole in the arm 2 being threaded. Finally, it should be emphasised that the invention is in no way restricted to the embodiments which have been described above, but several modifications are fea¬ sible within the scope of the inventive idea as expressed in the accompanying claims. It should also be pointed out that the concept of the invention is just as applicable to devices having a roller in rolling engagement with the side of the tyre (for instance CA-A-1, 138,314 and DE-A- 4,022,907) as to devices without such a roller (for in¬ stance SE-B-446,539 ), in which the rotatable member is flexible and in which the antiskid elements are attached to projecting radial fingers.

Claims: CLAIMS 1. An antiskid device for vehicles, comprising a holder ( 1 ) to be mounted in connection with a vehicle wheel ( 6), an arm (2) which is hingedly connected to the holder and which is actuatable between a working position for antiskid effect and a non-operative resting position; a spindle (5; 5a; 5b) attached to the arm (2); and a mem- ber (3) which is rotatably mounted on the spindle (5; 5a; 5b) and which carries at least one antiskid element (4) which in the working position is arranged to be thrown, by centrifugal force, in between the vehicle wheel (6) and the ground ( 13) , the angular position of the ro- tatable member (3) being adjustable relative to the side of the vehicle wheel (6), c h a r a c t e r i s e d in that the spindle (5; 5a; 5b) is rigid and, at its attach¬ ment to the arm ( 2) , is turnable about a predetermined axis (10) making a constant angle (α) with the axis of rotation (11; 11a) of the rotatable member (3) for ad¬ justing the angular position of the rotatable member (3) relative to the side of the vehicle wheel ( 6) , and that the spindle (5; 5a; 5b) has means (8, 9, 14) for locking thereof in different turning positions. 2. The antiskid device as claimed in claim 1, c h a r a c t e r i s e d in that said constant angle (α) is in the approximate range of 3-20°. 3. The antiskid device as claimed in claim 2, c h a r a c t e r i s e d in that the range of said angle is 5-10°. 4. The antiskid device as claimed in any one of claims 1-3, c h a r a c t e r i s e d in that said means for locking comprises a clamping member ( 8) and an abut¬ ment (14) which belong to the spindle (5; 5a; 5b) and are positioned on each side of the arm (2). 5. The antiskid device as claimed in any one of claims 1-4, c h a r a c t e r i s e d in that the spindle (5; 5b) comprises two portions (16, 17) the first portion (16) having, in the area of its attachment to the arm (2) , an extent which essentially coincides with said predetermined axis (10), about which the spindle (5; 5b) is turnable, while the other portion (17) has an extent which essentially coincides with the axis of rotation (11; 11a) of the rotatable member. 6. The antiskid device as claimed in any one of claims 1-5, c h a r a c t e r i s e d in that the spindle (5; 5a; 5b), at its attachment to the arm (2), is provided with at least one distance member (9) arranged around the spindle (5; 5a; 5b) and adapted to hold the rotatable member (3) at a predetermined distance from the arm (2) . 7. The antiskid device as claimed in claim 6, c h a r a c t e r i s e d in that the distance member (9 ) comprises an annular element (12; 12a) which is arranged between the arm (2) and the rotatable member (3 ) and which has a first surface which is perpendicular to the axis (10) of the spindle and a second surface making an angle with the first surface, said angle equalling said constant angle (α) . 8. The antiskid device as claimed in claim 6 or 7, c h a r a c t e r i s e d in that the spindle (5a) ex- tends through a hole (15) in the arm (2), and that por¬ tion of said spindle (5a) which is positioned in said hole (15) has a diameter which is smaller than the diame¬ ter of said hole (15), the spindle (5a) being located such that its centre axis (11a), in the area of said attachment, makes an angle with the centre axis (10) of the hole, said angle equalling said constant angle (α). 9. The antiskid device as claimed in any one of claims 1-8, c h a r a c t e r i s e d in that the ro¬ tatable member (3) is a roller which in the working posi- tion frictionally engages the side of the vehicle wheel (6). 10. The antiskid device as claimed in any one of claims 1-8, c h a r a c t e r i s e d in that the ro¬ tatable member is flexible and has projecting portions at whose outer ends said antiskid elements are attached. 11. The antiskid device as claimed in any one of the preceding claims, c h a r a c t e r i s e d in that said antiskid elements (4) consist of chains. 12. An adjusting device for a rotatable member (3), especially an antiskid-element-carrying member (3) be- longing to an antiskid device which is adapted to operate at the wheel (6) of a vehicle, said device comprising a spindle (5; 5a; 5b) on which the rotatable member (3) is mounted and which is attached to an arm (2) which is ac¬ tuatable between a working position and a resting posi- tion, the adjusting device permitting adjustment of the angular position of the rotatable member (3 ) relative to the side of the vehicle wheel (6), c h a r a c t e r ¬ i s e d in that the spindle (5; 5a; 5b) is rigid and, at its attachment to the arm (2) , is turnable about a prede- termined axis ( 10) making a constant angle (α) with the axis of rotation (11; 11a) of the rotatable member (3) for adjusting the angular position of the rotatable mem¬ ber (3) relative to the side of the vehicle wheel (6), and that the spindle (5; 5a; 5b) has means (8, 9, 14) for locking thereof in different turning positions. 13. A wheel-mounted vehicle, c h a r a c t e r ¬ i s e d in that it is provided with an antiskid device as claimed in any one of claims 1-11.

Inventors: HOLMGREN LARS, HOLMGREN, LARS
Applicants: HOLMGREN LARS, VBG PROD AB, HOLMGREN, LARS, VBG PRODUKTER AB
Application year: 1995
Main classification: B60B39
IPC codes: B60B39