FASTENING OR CLAMPING DEVICE

Abstract: The invention relates to a fastening or clamping device comprising a fastening or clamping element, for example a screw or a nut, and an operating knob connected with the fastening or clamping element. In order to prevent undue operation of the fastening or clamping element the fastening or clamping device according to the invention comprises a locking device (32), which is changeable between two different positions. In the first of these positions the locking device unrotatably fixes the operating knob (22) in relation to the fastening or clamping element (20) so that said element can be rotated by means of the operating knob. In the second of said positions the locking device allows the operating knob to be unobstructedly rotated in relation to the fastening or clamping device so that it is not possible to operate the fastening or clamping element by means of the operating knob.

Description: The present invention relates to a fastening or clamping device of the kind comprising a rotatable fastening or clamping element, for example a screw or a nut, and an operating knob connected with the fastening or clamping element. Devices of the kind defined above are often used in luggage carriers, such as roof racks, ski holders or the like, in order to connect the carriers to the edges of a car roof. Fastening or clamping devices of said kind are also used for retaining objects, for example surf boards, to luggage carriers for vehicles. Thereby, it is previously known to use different kinds of locking devices for preventing that the luggage carriers and/or the objects supported thereby are stolen. However, it brings about substantial additional costs to use conventional locking devices and therefore it is desirable to provide a fastening or clamping device which per se comprises a locking device, which prevents undue releasing of the fastening or clamping device and thereby prevents that the object fastened by means of the fastening or clamping device is stolen. In order to comply with this object the fastening or clamping device according to the invention comprises a locking device, which is adapted to take two different positions, a first position, in which the locking device unrotatably fixes the operating knob in relation to the fastening or clamping element in order to allow that said element is. rotated by means of the operating knob, and a second position, in which the locking device allows that the operating knob is unobstructedly rotated in relation-to the fastening or clamping element in order to prevent rotation thereof by means of the operating knob. Thereby, the fastening or clamping device can either comprise a locking device, which has a lock element which by means of a key in a conventional way is movable between the two positions, or comprise a fixing element which in said first position unrotatably fixes the knob in relation to the fastening or clamping element and which is easily detachable from the device so that the knob is in said second position unobstructedly rotatable in relation to the fastening or clamping device because of the fact that the fixing element has been detached from the device. In the first mentioned case an embodiment of the fastening or clamping device according to the invention is distinguished by the fact that a substantially annular portion is fixedly and substantially concentrically connected with the fastening or clamping element, that the operating knob encloses the annular portion and in said second position of the locking device is unobstructedly rotatable in relation to the fastening or clamping element and that the locking device is supported by the operating knob, the lock element firmly engaging the annular portion in said first position of the locking device and being out of engagement with the annular portion in said second position of the locking device. Thereby it is suitable that the locking device extends from the operating knob into the space enclosed by the annular portion and that the lock element is adapted to engage engagement surfaces at the inner surface of the annular portion in said first position of the locking device. The annular portion can be constituted by the edge portion of a cup-shaped portion which at its central portion is connected with the fastening or clamping device, and the operating knob can be constituted by a cup-shaped cover which is rotatably connected with the annular portion by means of locking lugs at the edge of the cover. The fastening or clamping device can comprise a fastening or clamping element in the form of a screw or a nut. If the fastening or clamping element is constituted by a nut the fastening or clamping device has a central through opening for a screw or the like, on which the nut is positioned. The invention is described in the following with reference to the accompanying drawings. Fig. 1 shows a support leg for a ski holder or a roof rack for cars, the support leg being provided with an embodiment of a fastening or clamping device according to the invention. Fig. 2 is an axial section of the fastening or clamping device of Fig. 1 on line Il-Il in Fig. 4. Fig. 3 is an axial section of the fastening or clamping device on line Ill-Ill in Fig. 4. Fig. 4 is a plan view of the fastening or clamping device according to Figs 1-3. Fig. 5 shows a modified embodiment of a fastening or clamping device according to the invention. In Fig. 1 there is shown a support leg 2 for a ski holder intended to be secured to the roof of a car and comprising a clamping device according to the invention. The support leg 2 comprises a first portion 4 having a lower part 6 adapted to be received in the gutter of the car roof. The support leg 2 also comprises a clamping portion 10 which is at its upper end 8 movably connected with the portion 4 and has a lower annular part 12 adapted to engage below the gutter of the car roof when the support leg is secured thereto. The clamping portion 10 is connected with the portion 4 by means of a pin 14 supported by the portion 4 and received in a slot 16 in the clamping portion 10. The support leg 2 s securable to the gutter of the car roof by operating the clamping portion 10 by means of a clamping device 18 comprising a clamping element in the form of a screw 20 and an operating knob 22 connected therewith. The screw 20 extends through a threaded opening in a boss 24 on the portion 4 and has its end engaging the central portion of the clamping portion 10. When the screw 20 is screwed into its threaded opening the end of the screw is pressed against the clamping portion 10 so that the support leg 2 is secured to the roof gutter. In order to prevent undue releasing of the screw 20 which in turn could allow that the ski holder was stolen the fastening or clamping device 18 is in accordance wit-h the invention designed in a special way. The screw 20 supports a cup-shaped portion 24, which at its central part is fixedly connected with a head 26 of a screw 20. The cup-shaped portion 24 has an annular portion 28 which is formed with a number of depressions 29. The depressions 29 are intended to constitute engagement surfaces for a purpose which is described in the followings Thecup-shaped portion 24 with its annular portion 28 is enclosed by the operating knob 22 which also is substantially cup-shaped. At its free edge portion the cup-shaped operating knob 22 has a number of inwardly bent locking lugs 30 preventing the cup-shaped knob from being detached from the cupshaped portion 24 but providing such a loose connecting between the operating knob 22 and the cup-shaped portion 24 with the annular portion 28 that the operating knob 22 is unobstructedly rotatable in relation to the cup-shaped portion 24 and thereby-also in relation to the screw 20. The operating knob 22 supports a locking device 32 which comprises a locking element 34 which in a conventional way is switchable between two different positions by means ofa key Inthe position of the locking device 32 as shown in Figs 2-4 the locking-element 34 engages one of the depressions 29 of the operating knob 22. In this position the operating knob 22 is through the locking device 32and the annular portion 28 of the cup-shaped portion 24 connected with the screw 20 in such a way, that a rotation of the operating knob 22 provides for a rotation of the screw 20. In order to prevent undue operation of the screw 20 in order-to-ldosen the ski holder from the car roof the locking element34 of the locking device 32 is by means of the key switched from the position of engagement in the depression 29. In this position the operating knob 22 is unobstructedly rotatable in relation to the annular portion 28 for which reason it is not possible to operate the screw 20by means of the operating knob 22 Thus, it is in this position not possible to steal a ski holder or the like which is secured to a car roof by means of a support leg of the kind shown in Fig. 1. In Fig. 5 there is shown a support leg 2a for a ski holder adapted to be secured to a car roof The support leg 2a comprises a modified embodiment of a clamping device according to the invention. The support leg 2 comprises a first portion 4a having a lower part 6a adapted to be received in the gutter of the car roof. The support leg 2a also comprises a clamping portion 10a which is at its upper end 8a movably connected with the portion 4a and has a lower annular part 12a adapted to engage below the gutter of the car roof when the support leg is secured thereto. The clamping portion 10a is connected with the portion 4a by means of a pin 14a supported by the portion 4a and received in a slot 16a in the clamping portion 10a. The support leg 2a is securable to the gutter of the car roof by operating the clamping portion 10a by means of a clamping device 18a comprising a clamping element in the form of a screw 20a and an operating knob 22a connected therewith. The screw 20a extends through a threaded opening in a boss 24a on the portion 4a and has its end engaging the central portion of the clamping portion 10a. When the screw 20a is screwed into its threaded opening the end of the screw is pressed against the clamping portion I0a so that the support leg 2a is secured to the roof gutter. In accordance with the invention the knob 40 for providing the rotation of the screw 38 comprises two portions, namely a first portion 44 fixedly connected with the screw and an outer portion 46 having the form of a cover enclosing the portion 44. The cover 46 has an inwards extending edge portion 48 which prevents releasing of the cover from the portion 44 but encloses the portion 44 with such a loose connection that the cover 46 is unobstructedly rotatable in relation thereto. Each of the portion 44 of the knob and the cover 46 are provided with two openings 50 and 52, respectively, which are positionable axially in relation to each other by rotating the portion 44 in relation to the cover 46. By introducing a fixing element 54 in the openings 50 and 52 it is possible to fix the portion 44 in relation to the cover 46, so that it is possible to rotate the screw 38 by operating the cover 46 in order to provide fastening or loosening of the support foot 2a from the gutter of the car roof. When the fixing element 54 has been removed it is-not possible to steal a ski holder or the like which is secured to a car roof by means of a support leg of the kind shown in Fig. 5. it is, of course, possible to provide the connection between the portion 44 and the cover 46 in many different ways. Thus, it is possible to provide the knob with a central opening of non-circular shape, whereby the connection of the two portions of the knob can be provided by introducing a fixing element in said opening. The invention can be modified within the scope of the following claims. For example the fastening or clamping device according to the invention can comprise a nut as the fastening or clamping element instead of the screw shown in the above described embodiments. A fastening or clamping device of this kind can advantageously bused forlocking an object to a luggage or load carrier for vehicles. For example the object can be a surf board. In the case that the fastening or clamping element is constituted by a nut the fastening or clamping device is formed with a through opening for the threaded pin or screw on which the nutis positioned.

Claims: CLAIMS 1. A fastening or clamping device comprising a rotatable fastening or clamping element (20; 38), for example a screw or a nut, and an operating knob (22; 40) connected with said fastening or clamping element, c h a r a c t e r i z e d. by a locking device (32; 54j, which is changeable between two different positions, a first position in which the locking device unrotatably fixes the operating knob (22; 40) in relation to the fastening or clamping element (20; 38) for allowing that said element is rotated by means of the operating knob, and a second position in which the locking device allows the operating knob to be unobstructedly rotated in relation to the fastening or clamping device in order to prevent rotation thereof by means of the operating knob. 2. A fastening or clamping device as claimed in claim 1, c ha r a c t e r i z e d in that a substantially annular portion (28) is fixedly and substantially concentrically connected with the fastening or clamping element (20), that the operating knob (22) encloses the annular portion and in said second position of the locking device (32) is unobstructedly rotatable in relation to the fastening or clamping element and that the locking device is supported by the operating knob and is provided with a lock element (34), which in said first position of the locking device is in firm engagement with the annular portion and in said second position of the locking device is out of engagement with the annular portion. 3. fastening or clamping device as claimed in claim 2, c h a r a c t e r i z e d in that the locking device (32) extends from the operating knob (22) into the space enclosed by the annular portion (28) and the lock element (34) is adapted to engage engagement surfaces (22j at the inner surface of the annular portion in said first position of the locking device. 4. A fastening or clamping device as claimed in claim 2 or 3, c ha r act e r i z e d in that the annular portion (28) constitutes the edge portion of a cup-shaped portion (24) which is connected with the fastening or clamping element (20) at its central portion. 5. A fastening or clamping device as claimed in any of claims 2-4, c h a r a c t e r i z e d in that the operating knob (22) is constituted by a cup-shaped cover, which is rotatably connected with the annular portion (28) by means of locking lugs (30) provided at the edge of the cover. 6. A fastening or clamping devices claimed in claim 1, c h a r a c t e r i z e d in that the locking device comprises a fixing element (54),- by means of which the operating knob (40) is fixable in relation to the fastening or clamping element, the fixing element being. easily removable from the device for preventing undue releasing of the fastening or clamping element (38). 7. A device as claimed in claim 6, c h a r a c t e r i z e d by a portion (44) which is firmly connected with the fastening or clamping element (38) and is enclosed by the-operating knob and that the fixing element (54) is adapted to fix the knob in relation to the portion (44) connected with the fastening or clamping element, 8. A device as claimed in claim 7, c h a r a c t e r i z e d in that the operating knob (46) is connected with the portion (44) which is connected with the fastening or clamping element by means of an inwards bent edge portion (48). 9. A fastening or clamping device as claimed in any of the preceding claims, c h a r a c t e r i z e d in that the fastening or clamping element- (20; 38) is constituted by a nut and that the fastening or clamping device has a central through opening for a screw or the likes on which the nut is adapted to be positioned.

Inventors: THULIN, WILLIS
Applicants: INDUSTRI AB THULE
Application year: 1980
Main classification: F16B41
IPC codes: F16B41