LOCKING DEVICE

Abstract: A device with which detachably to lock two elements to each other, said elements when not locked being telescopically displaceable relative to each other. The device comprises an insert (3), which may be entered into the outer element (1) and locked therein, and which comprises at least two sections (8, 9), each of said sections extending circumferentially along at least more than half the circumference of the inside of said outer element. Between the two sections the insert is provided with on the one side of the inner element (2) a distance piece (10) and on the other side thereof a cut (13). The insert is provided with a through conduit for the inner element (2) which is to be displaceable telescopically and lockable with respect to the outer element (1). In the area of said distance piece, the insert is provided with a larger inner radius or diameter than in the area of said sections. A locking element (4) is placed in the clearance between the outer and the inner elements, and means (5, 6) are provided by which to press the locking element against the inner element by pressing the locking element radially inwards from the outside, thereby clamping said element between on the one hand the inside of the locking element and on the other side the insides of the two sections.

Description: _ _ LOCKING DEVICE TECHNICAL SCOPE The invention relates to a device with which detachably to lock two elements to each other, said elements being telescopically displaceable relative ' to each other when not locked. BACKGROUND ART My previous Swedish Patent No 8203018-0 (428 243) relates to a locking device of the type mentioned in the preamble. According to this earlier invention there is a circumferential recess in the area of the inside of the outer element. In this recess there is provided a sleeve, the outer diameter of which is less than the outer diameter of the recess, the sleeve thus being displaceable in the radial direction in the recess. By means of a screw or some other locking element, the sleeve may be displaced radially in the recess, thus being pressed against the inner element. Said inner element thereby is locked between on the one hand the inside of said sleeve in th.e area of the pressing force, and on the other hand the inside of the outer element on both sides of the recess. The locking device is very simple yet provides for very efficient locking. Considering that it is applicable within a vast array of different areas, it has been a considerable technical improvement in the art. DISCLOSURE OF THE INVENTION The object of the invention is to provide a locking device based on the same principle as my previous invention, described above, but constituting an improvement thereof. In particular, an object is to provide a locking device which may more easily be pre-manufactured, so as to be even more easily integrated with the outer element. Another object is to make it possible to let the material of the runners or the like surrounding the mobile locking element be thinner. These and other objects may be realized by including in the locking device an insert which may be. entered into the outer element and be locked therein and which comprises two sections, each section extending at least along more than half of the circumference of the inside of the outer element, by providing between said two sections on one side at least one distance piece and on the opposite side a full cut in the insert, i e a through slot therein, by providing the insert with a through conduit for the inner element which is to be displaceable telescopically and be lockable with respect to the outer element, by making the insert inner diameter larger in the area of said distance piece than in the area of .said sections, by enclosing a locking element in the slot between the inner and the outer elements, and by providing means by which to press the locking element from the outside radially inwards against the inner element, thereby clamping said element between on the one hand the inside of the locking element', and on the other hand, the insides of the two sections on either side of the locking element. The two telescopic elements are cylindrical and their cross- section may be circular, oval, polygonal or of other form, as long as said form permits the radial movement necessary for the clamping function. The insert may be manufactured of moulded plastic, but may also be manufactured by turning, by casting, by sheet metal pressing, etc. In the latter case, the expanded diameter in the distance piece may be created during the pressing operation. The two sections of the insert may be in the form of all-encompassing cylinders, and at least one of the said sections should be of this form, while the other may be provided with a cut on the same side as the cut between the two sections, to facilitate the entry of the insert into the outer element, since the outer element is provided with a rivet or some other elevation by which to attach a nut or the like, which is in turn intended to interact with a screw or suchlike, said screw pressing the locking element against the inner element. The outer end of one of the sections is preferably fitted with an external flange, functioning as a stop flange against the end of the outer element when the insert is entered into the outer element. The distance piece is preferably designed as a continuous bridge between the two sections. The larger diameter in the area of the distance piece is created by providing the distance piece with a groove on the inside. As an alternative, or in combination with this may be arranged two or more, suitably parallel, distance pieces in the form of bridges between the sections, the spaces between the bridges possibly being empty, i e consisting of several cuts in the insert. If these bridges lie on the same side of a diametrical plane (if the insert cross-section is not circular or oval, of a plane corresponding to the diametrical plane) as the locking element, the bridges may be of the same inner diameter as the inserts. If not, their diameter is larger than that of the inserts, i e they are grooved as indicated above. Further characteristics, aspects, and advantages of the invention will appear from the patent claims and from the following description of a preferred embodiment. BRIEF DESCRIPTION OF DRAWINGS In the following description of a preferred embodiment, reference will be made to the accompanying drawings, wherein Fig. 1 is an exploded view of the locking device including the outer and the inner elements according. to a first preferred embodiment of the invention; Fig. 2 is a perspective view of an insert illustrated in Fig. 1; Fig. 3 is an elevation of the device according to the preferred embodiment; Fig. 4 shows the same device with the outer element partly removed; Fig. 5A is a section along V-V in Fig. 3 and shows the device in the locked state; Fig..5B shows the device when not locked; Fig. 6 is a longitudinal section along VI-VI in Fig. 5A; Fig. 7 . is a transverse section of the insert, corresponding to Figs. 5A and 5B; and Fig. 8 is a perspective view of an insert according to an alternative embodiment of the invention. DESCRIPTION OF A PREFERRED EMBODIMENT Referring now to Fig. 1, reference numeral 1 indicates an outer tubular telescopic element, 2 indicates an inner tubular telescopic element, 3 indicates an insert, 4 indicates a locking element, and 5 indicates a locking screw. In this embodiment, the telescopic elements 1 and 2 are cylindrical. The outer diameter of the inner element is smaller than the inner diameter of the outer element. The locking screw 5 may be screwed into the outer element 1 via a blind rivet nut 6 fastened to the outer element, the rivet head being located on the inside of the outer element 1, Figs. 5A and 5B. The insert 3 will be described in greater detail below, with reference to Fig. 2. The insert 3 consists of an inner and an outer section 8 and 9, respectively, the word "inner" signifying that the said section is placed further inside the outer element 1, and an intermediate piece 10 connecting the two sections 8 and 9. The outer section 9 is cylindrical and the outer diameter thereof corresponds so closely to the inner diameter of the outer element 1 that the insert 3 may be entered into the outer element with a close fit and be retained by the force of friction. According to the embodiment, the insert 3 is made of moulded plastic, but as was mentioned earlier, it could well be made of metal or of some other material. Instead of being retained by friction, it could of course be fixed in the outer element 1 by shrinking, screwing, soldering, riveting, welding or elsewise. The outer contour of the inner section 8 is also cylindrical, like the inside of the outer element 1, but is provided wi.th a cut 11, which permits the insert to be entered into the outer element, in spite of the presence of the rivet head 7 on the inside thereof. The intermediate piece 10 is designed with the same circular cylindrical outer contour as the sections 8 and 9, but on the inside of the intermediate piece 10 there is a groove 12 extending between the two sections 8 and 9. The intermediate piece 10 is in the form of a half cylinder. The half-cylindrical cut thus formed between the sections 8 and 9 opposite the groove 12 has been indicated by numeral 13. An outwardly directed stop flange at the outer end of the outer section 9 has been indicated by numeral 14. The locking element 4 consists of a piece of sheet metal, bent into a cylindrical segment. The peripheral length of the locking element 4 is slightly less than that of the cut 13 and it is slightly thinner than the intermediate piece. The device is assembled by slipping the insert 3 over the inner element 2 and placing the locking element 4 in the cut 13, as is illustrated in Fig. 1. Then, the insert 3 and the locking element 4 may be entered into the outer element 1, until the stop flange 14 buts against the outer end of the outer element 1. The insert 3 is retained in the outer element 1 by friction or elsewise, as indicated above. When not locked, the inner element 2 may move freely inside the insert 3. To lock the two elements 1 and 2 to each other, the locking screw 5 is moved inwards to engage the locking element 4, thereby pressing said element against the inner element 2 in the area of the cut 13 by displacing it in the radial direction. The inner element 2 is in turn pressed radially against the sections 8 and 9 on either side of the groove 12, Fig. 6, which brings about the same efficient locking as in the case of my previous invention, mentioned earlier. The locking element 4 may consist of some other hard material than sheet metal. It may also be clad with rubber or some other high-friction material on the inside. In Fig. 8 is illustrated an alternative embodiment of the insert, designated 3'. It is provided with a stop flange 14, but the material thickness is otherwise constant. This insert is characterized by being provided with two bridges 10' and a locking element, not shown, of circular-cylindrical form, which may be placed in either of the cuts 13' between the bridges 10' . The opposite cut will then form the clearance inside the outer element necessary according to the basic principle of the invention to form a "three-point-clamp".

Claims: CLAIMS: 1. A device for the releasable locking of two elements to each other, said elements when not locked being telescopically displaceable relative to each other, c h a r a c t e r i z e d i n that the locking device comprises an insert (3) which may be entered into the outer element and be locked therein and which comprises at least two sections (8, 9), each extending at least around more than half of the circumference of the inside of the outer element, that between said two sections is provided on one side of the inner element at least one distance piece (10) and on the opposite side thereof a full cut (13) in the insert, i e an open slot therein, that the insert is provided with a through conduit for the inner element (2) which is to be displaceable telescopically and be lockable with respect to the outer element (1) , that the inner diameter of the insert is larger in the area of said distance piece- than in the areas of said sections, that a locking element (4) is enclosed in said cut in the clearance between the inner and the outer elements, t and that means (5, 6) are provided to press the locking element from the outside radially inwards against the inner element, thereby clamping said inner element between on the one hand the inside of the locking element, and on the other hand, the insides of the said two sections. 2. Device according to claim 1, c h a r a c t e r i z e d i n that said two sections are connected to each other to form a unit by one or several bridges, said bridge/s/ forming said distance piece. 3. Device according to claim 1, c h a r a c t e r i z e d i n that said locking element (4) extends circumferentially essentially, though not entirely, to fill said cut between said two sections. /03562 „,---, _-„ ' PCT/SE85/00486 — 8 — 4. Device according to claim 3, c h a r a c t e r i z e d i n that said locking element is in the form of a segment of a cylinder, said segment extending over less than half the circumference of said inner element, the locking element thus not gripping the inner element. 5. Device according to claim 3, c h a r a c t e r i z e d i n that said locking element is in the form of a segment of a cylinder,, said segment extending over more than half the circumference of said inner element, the locking element thus gripping the inner element.

Inventors: HOEISETH JOHN, HOEISETH, JOHN
Applicants: HOEISETH JOHN, HOEISETH, JOHN
Application year: 1985
Main classification: F16B7
IPC codes: F16B7