Background of the Invention
The invention relates to an attachment means which has to execute a rotary movement for attaching and releasing purposes. Such an attachment means is e.g. a threaded bolt, a nut or a part of a bayonet fixing. In particular, the underlying idea is e.g. the attachment of a rack on the roof of a car, which rack is often attached with bolts.
For the required protection against theft, there is increasingly used a lock construction for attaching products to be conveyed on a rack, such as a surfing board, skis or other components of high value. In practice, however, it appears simple to release the rack itself together with the load attached thereon through locks.
It is the object of the invention to provide a simple, inexpensive and effective attachment means which is provided with a lock and which practically excludes theft.
To this effect according to the invention, it is proposed to incorporate the attachment member performing the rotary movement, with at least one end axially locked up, in a knob, while attaching a lock eccentrically relative to the attachment member in the knob, said lock in a first locked position releasing the attachment member so that it is adapted for free rotation relative to the knob and whereby in a second position of the lock, the knob is locked relative to the attachment member. Preferably, use is made therefore of a locking means carried in the knob, said locking means coacting with a correspondingly formed face on the attachment member. Preferably the knob is recessed at the back side, so that the knob shuts off the access to the attachment member itself.
One embodiment and a variant thereof will now be described, by way of example, with reference to the accompanying drawing, while also further features of the invention will be elucidated.
Brief Description of the Drawings
FIG. 1 is a perspective and diagrammic view of a partial cross section of the attachment means according to the invention.
FIG. 2 is a view, partly in cross section, on the lines II--II in FIG. 1;
FIG. 3 is a view according to FIG. 2 of a variant embodiment.
Detailed Description of the Invention
In FIG. 1 are shown two retainer parts 1, and 2, which are to be attached to each other in such a way that these can be secured by a lock. In this example retainer part 2 is fitted with a blind hole 3 provided with a screw thread wherein can be screwed a threaded element 4, e.g. a threaded fastener or attachment member. By means of such attachment portion 4, the other portion 1 can be fixedly attached on retainer part 2. To this effect, part 1 is provided with a continuous bore 5 through which the element 4 can freely move. The part 1 is fitted with a raised boss 6. Element 4, above the threaded end portion 7, has a smooth neck portion 8 which extends from an annular shoulder 9. Above said shoulder there is disposed a substantially square head portion 10, whose faces are concave and serve as locking faces. The element 4 is disposed with one end in a knob generally indicated by 12. Said knob is provided with a projecting edge 13 within which the raised boss 6 is situated. The element 4 is maintained in position through a retainer plate 14, which, by means of three bolts 15, only one of which being indicated, is attached in the knob 12. The retainer plate 14 is fitted with a central bore 16 whereby it abuts against the shoulder 9 and thus functions as a guide for the smooth neck portion 8 of element 4. The circular cylindrical bearing portion 11 of fastener 4 is slidingly received in a bore 16 in the knob 12. In the position shown, see also FIG. 2, the knob 12 can freely rotate relative to element 4.
The knob and the fastener head, are axially locked relative to each other by the retainer plate 14.
Eccentrically in the knob 12 there is provided a cylindrical lock 17, which lock is provided with an outer cylinder having a support rim 18 and secured at the inside by means of a threaded ring 19. On the end 20 of the usual key-rotatable plug, there is present a head portion whereon is secured a locking arm 21 through a bolt 22. Preferably, the lock is so designed that in two positions, differing e.g. 90.degree. or 180.degree. from each other, the key can be removed from the lock. At any rate the key should be removable when the locking arm 21 is in the position shown in full lines in FIG. 2.
In the position 21' of the locking arm shown in broken lines in FIG. 2, the end of the locking arm rests against one of the faces of the head portion 10.
In order to easily effect the locking, there is disposed opposite the plug, hence at the other side of the head portion, a leaf spring 30, which is secured in a slot 31 in the knob 12. As a result, it can be easily felt when the knob is in such a position relative to the element 4 that the lock plug can be rotated.
When the lock is in the position shown in FIG. 1 and FIG. 2, the element 4 is freely rotatable relative to the knob. The knob may then freely rotate and unauthorized release of the threaded connection is not possible in a simple manner. Since the threaded pin is disposed in a blind hole, said pin cannot be approached from the other side either. Because of the raised boss portion 6, which is contained within the projecting edge 13 of the knob 12, destruction of the threaded pin, e.g. by sawing through same, cannot be attained without completely destroying the knob. Depending on the contemplated application and the required strength, the knob can be made of plastics, reinforced plastics, (injection-moulded) aluminium, bronze, steel or other suitable material. Naturally, the knob 12 need not be of circular cross, section but may also be rectangular, straight-shaped or designed as a handle, provided only the lock can be eccentrically mounted and the access to the threaded pin in mounted condition is screened.
FIG. 3 shows a variant of a locking device, wherein the key-actuated locking member is operational in the same manner as arm 21 of the first embodiment and comprises a disc cam 40. Said disc cam is acting on a rectangular locking plate 41, which is locked right-angled to the plane of drawing, in a manner not shown, e.g. by means of a retainer plate 14 as shown in FIG. 1. Said locking plate 41 moves in the direction of the arrow 42 within a groove 43. Opposite the disc sam 40 there is provided a spring 44, which urges the locking plate 41 in the plane of drawing of FIG. 3 downwardly. The head of threaded element 4 in this example has a hexagonal head cross-section, so that a plurality of locking faces 45 is formed. Said locking faces coact with a correspondingly formed aperture portion 46 in the locking plate 41, so that in the illustrated position there is effected a fixed connection between element 4 and the knob 12, not shown. When the lock is rotated through 180.degree., also the disc cam 40 rotates through 180.degree.. During the rotation of the lock, the locking plate 41 is urged upwardly, so that the curcular portion 47 of the aperture becomes coaxial with element 4 and the locking faces 45. Said aperture portion 47 is so large that in this coaxial position the knob can freely rotate relative to the hexagon faces 45 on element 4. In said position therefore the connection between knob and element 4 is broken as far as the rotation is concerned.
It is observed that the locking device fitted with a lock according to the invention is not only suitable for application in a threaded pin, but that it is likewise possible to apply within the knob a nut which normally is enclosed in the knob, but a rotary motion of which is possible relative to the knob, whereby also in such case, by means of a lock, clutching can be effected between knob and nut. In particular the variant shown in FIG. 3 is naturally suitable for ensuring an effective locking when the nut has a hexagonal design at the exterior. The construction is also suitable for any other connection, whereby a rotational motion has to be effected and locked, e.g. in a bayonet fixing.