LOCKABLE TELESCOPIC DEVICE AND USE OF THE SAME

Abstract: The invention relates to a lockable telescopic device (1) which includes a cylindrical tube (10) and a piston rod (3). The piston rod (3) includes an expandable locking device (60) which, when active, forcibly abuts a part of the inner wall of the tube (10). The expandable locking device (60) includes two sleeves (61, 62) which accompany movement of the piston rod (3) in the longitudinal direction of the device (1). The piston rod (3) and the tube (10) are locked against relative movement by rotating the sleeves (61, 62) relative to one another with the aid of a lever (51) mounted on the piston rod. The invention also relates to the use of the lockable telescopic device in conjunction with so-called engine shelves.

Description: LOCKABLE TELESCOPIC DEVICE AND USE OF THE SAME The present invention relates to a lockable telescopic device according to the preamble of Claim 1 and to the use of the lockable telescopic device. There are many situations in which there is a need for a simple and reliable telescopic device which will enable objects and apparatus of different kinds to be adjusted to different positions and firmly locked therein. The object of the present invention is to provide an attractive device of the aforesaid kind. This object is achieved with a lockable, telescopic device that has the features set forth in the following Claims. One advantage afforded by the invention, among other advantages, is that the device can be readily adjusted to different lengths and locked in its adjusted posi¬ tion, and can be used in extremely difficult environ¬ ments. The invention will now be described in more detail with reference to an exemplifying embodiment thereof and also with reference to the accompanying drawings, in which Fig re 1 is a longitudinal view of the inven¬ tive device; Figure 2 is a cross-sectional view in larger scale taken on the line II-II in Figure 1; Figure 3 is a longitudinal sectioned view of the device; and figure 4 is a cross-sectional view in larger scale taken on the line IV-IV in Figure 3. The illustrated inventive telescopic device 1 compris- es a cylinder 2 and a piston rod 3. The cylinder 2 is constructed around a cylindrical tube 10 which is sealed at its rearward end by an attachment in the form of a sleeve 11 welded to said end. Also mounted on the rearward end of the cylinder 2 is- a nipple 12 for connection to a hydraulic system, when used. As will be seen from Figure 2, the tube 10 is provided internally with a keyway 13 which extends along at least a major part of the length of the cylinder 2. Fitted to the forward end of the cylinder 2 is a so- called cylinder cover 14 which is screwed to the tube 10 by means of a screw joint 15. The cylinder cover 14 includes a central opening and carries three ring seals in the form of a stripper or wiper 16, a u-cuff 17 and an O-ring 18. A stop shoulder 19 is mounted on the outside of the tube 10. The piston rod 3 comprises a circular rod 30 having a centre part 31 whose diameter is adapted to the inter¬ nal diameter of the tube 10 and the cover 14. The rearward end of the rod 30 is provided with a shoulder 32 whose diameter is smaller than the diameter of the centre part 31. The shoulder 32 is provided with a keyway 33. The forward and free end of the rod 30 is provided with a shoulder 34 whose diameter is smaller than the diameter of the centre part 31 of the rod 30. The shoulder 34 carries a so-called toggle-link bearing 35 having an outer ring 36 which is fixed with the aid of a locking ring 37, for instance, to an attachment in the form of a sleeve 38. The toggle link bearing 35 is fixed to the rod 30 by means of an end-plate 39 screwed to the forward end of the rod 30. Fitted to the rod 30 is a rotary device 50 by means of which the piston rod 3 can be rotated relative to the cylinder 2. The rotary device 50 includes an operating lever 51 which is welded to the rod 30. The lever 51 carries stop means 52, the construction of which will be seen from Figures l and 2. The shoulder 32 on the rod 30 carries the inventive locking device 60. The locking device 60 includes an eccentric sleeve 61 and a slotted outer sleeve 62. The internal shape of the outer sleeve 62 is adapted to the outer shape of the eccentric sleeve 61 and the outer shape of the outer sleeve 62 is circular and adapted to the cylindrical tube 10. The eccentric sleeve 61 has a key 63 which coacts with the keyway 33 in the shoulder 32, so as to cause the eccentric sleeve 61 to accompany rotary movement of the piston rod 3. The eccentric sleeve 61 and the outer sleeve 62 are fixed axially in relation to the shoulder 32 on the piston rod, by means of an end-plate 40 screwed firmly to the piston rod 3. As will be seen from Figure 4, the eccentric sleeve 61 includes on its peripheral surface two eccentric parts 64, 65 which are defined by two transition edges 66, 67. The outer sleeve 62 includes internally two eccentric parts 68, 69 which coincide with the eccen¬ tric parts 64, 65 of the eccentric sleeve 61, these eccentric parts 68, 69 also being defined by two transition edges 70, 71. The outer sleeve 62 is pro¬ vided with a slot 73 which enables the outer sleeve to expand. In the relative position of rotation of the sleeve 61 and 62 shown in Figure 4, the transition edges are in mutual abutment and the slot 73 has a minimum width. In this operational state of the ar¬ rangement, the piston rod 3 can move relative to the cylinder 2 since the sleeve 62 will then have an outer diameter with which no frictional engagement occurs between the tube 10 and the sleeve 62. In this free- state of the locking device, the operating lever 51 is in a position in which the stop shoulders 19 and 52 are in mutual contact, as shown in Figures l and 2. The outer sleeve 62 has an external key 72 which coacts with the keyway 13 in the tube 10. When adjusting the length of the telescopic device by means of the piston rod 3, the key 72 will slide along the keyway 13. The inventive locking device 60 is used and operates in the following manner: It is assumed that the aforedescribed telescopic device 1 is secured, via its attachment points 11 and 38, to an object whose position is to be adjusted and which is to be locked in its adjusted position. It is also assumed that the lever 51 is located in the free position shown in Figures 1 and 2 and that the locking device 60 is therewith inactive. A manually operated hydraulic pump is connected tempo¬ rarily to the nipple 12 and the telescopic device 1 is then adjusted to a desired length with the aid of the pump, since hydraulic fluid delivered by the pump will act between the cylinder 2 and the piston rod 3. When the device 1 has been adjusted to the length desired, the piston rod 3 is locked relative to the cylinder 2 by turning the lever 51 in the direction of arrow A. The eccentric sleeve 61 accompanies this movement of the lever and thus rotates relative to the outer sleeve 62. As a result of the earlier described eccen¬ tricity, this relative rotation of the sleeves 61 and 62 will cause the outer sleeve 62 to expand into pressure abutment with the inner surface of the tube 10. The slot 73 widens as the outer sleeve 62 expands. The pump can be disconnected from the device l, when the lever 51 has been rotated to achieve effective locking between the piston rod 3 and the cylinder 2. The telescopic device 1 can be easily adjusted to a new length, by again connecting a hydraulic pump to said nipple and releasing the eccentric locking action by rotating the lever 51 to the free position/end position shown in Figures 1 and 2, whereafter the piston rod is moved to a new, desired position and the lever 51 is turned in the direction of arrow A until the device is firmly locked, and so on. One particularly interesting field of use for the inventive device 1 is found in so-called engine shelves, where the device 1 can replace conventional adjusting screws used to adjust a pivotally mounted engine shelf to an appropriate angle in conjunction with adjusting the tension of V-belts and the like. It will be seen, however, that the inventive device can be used in many different areas. It will also be understood that the device is not always dependent on the use of a hydraulic pump when adjusting the length of the inventive device. It will also be understood that the inventive device is not restricted to the illustrated and described embodiments thereof and that modifications can be made. For instance, the attachments 11 and 38 may be different to that described and illustrated. The stop shoulders 19 and 52 are mainly intended to protect the keys 63 and 72 and the transition edges 66, 67 and 70, 71, and are not therefore necessary features of the manner in which the inventive device functions. It will also be understood that the eccentric sleeve 61 and the outer sleeve 62 can be modified within certain limits. The keys 63 and 72 may, of course, be separate parts or may be exchanged for other compo- nents of equivalent function. According to one embodiment of the invention, the eccentric sleeve 61 may be an integral part of the piston rod 3, i.e. formed integrally with the piston rod 3. The invention is thus not restricted to the described and illustrated embodiments thereof, since changes and modifications are conceivable within the scope of the following Claims.

Claims: CLAIMS 1. A lockable telescopic device comprising a cylin¬ drical tube (10) and a piston rod (3), wherein the piston rod (3) includes an expandable locking device (60) which, in its active position, is in pressure abutment with a part of the inner wall of the tube (10), c h a r a c t e r i z e d in that the expand¬ able locking device (60) includes an eccentric sleeve (61) which is non-rotatable in relation to the piston rod (3) or which is integral with said piston rod (3); and in that the locking device (60) includes an outer sleeve (62) which is slidable and non-rotatable in relation to the tube (10). 2. A device according to Claim 1, c h a r a c ¬ t e r i z e d in that the outer sleeve (62) is pro¬ vided with at least one slot (73) so as to enable the sleeve to expand. 3. A device according to Claim 1 or 2, c h a r a c ¬ t e r i z e d in that the eccentric sleeve (61) and the outer sleeve (62) are fixed axially to the piston rod (3) such as to accompany movement of said piston rod. 4. A device according to any one of Claims 1-3, c h a r a c t e r i z e d in that the peripheral surface of the eccentric sleeve (61) includes two eccentric parts (64, 65) which are terminated by transition edges (66, 67). 5. A device according to any one of Claims 1-4, c h a r a c t e r i z e d in that the outer sleeve (62) has a centre hole which includes two eccentric parts (68, 69) which are terminated by transition edges (70, 71); and in that the outer sleeve (62) has a circular peripheral surface. 6. A device according to any one of Claims 1-5, c h a r a c t e r i z e d in that the piston rod (3) is provided with an operating device (51) which en¬ ables the piston rod (3) to be rotated relative to the tube (10). 7. A device according to any one of Claims 1-6, c h a r a c t e r i z e d in that the tube (10) has a working fluid connection point (12). 8. A device according to any one of Claims 1-7, c h a r a c t e r i z e d in that the tube (10) and the piston rod (3) are provided with attachment means (11 and 38 respectively) for connecting the device to an object. 9. The use of a lockable telescopic device according to any one of Claims 1-8, c h a r a c t e r i z e d in that the device is used to adjust the angular position of a so-called engine shelf in conjunction with adjusting belt tension and like tasks.

Inventors: PAULSSON ROGER, PAULSSON, ROGER
Applicants: GEMA MEKAN AB, PAULSSON ROGER, GEMA-MEKAN AB
Application year: 1993
Main classification: F15B15
IPC codes: F15B15