DD294761A5 - CONNECTING ELEMENT AND METHOD OF MANUFACTURING - Google Patents

Abstract

A connecting element for connecting a component to an adjacent component has a plurality of sleeves (71, 72), each provided with a cut-out (77) and a projection (74), the projection (74) of the one sleeve (71, 72) in each case engaging in the cut-out (77) of the other sleeve (71, 72). The sleeves (71, 72) rest with a clearance fit on an inner wall of a tube (14) which is to be mounted on a connecting body (13). A clamping screw (7) is screwed into a thread (9) of the connecting body (13) and thereby clamps the sleeves (71, 72) against one another, the projections (74, 87) penetrating deeper into the cut-outs (77, 92) and in this way driving onto the circumference of the sleeves (71, 72) until the said sleeves (71, 72) are firmly clamped to the inner wall. The sleeves (71, 72) are held on one another, flush with one another, by means of a toothed system. The unwound shapes of the sleeves (71, 72) are stamped out of steel strips and are subsequently formed into cylindrical sleeves (71, 72). The connecting element (70) can be used especially for the production of shelves, sales stands, racks and similar tubular constructions, and as so-called expanding dowels, the captive retention of the sleeves (71, 72) with one another and with the clamping screw (7) permitting installation to be carried out quickly and simply. <IMAGE>

Description

For this 2 pages drawings

Field of application of the invention

The invention relates to a connecting element for fastening adjacent components, which is clamped in a hole eirrn component, and to a method for producing the connecting element.

Characteristic of the known state of the art

A Verbinü ngselement of this type is described in CH-PS429317 and is used in rack construction for the production of pipe joints. It consists of two identical wedge sleeves, which lie within a to be fastened to a connecting body pipe end with their oblique sliding surfaces to each other. By a screwed into a thread of the connecting body, passing through the necks through the clamping screw, the two wedge sleeves, since they are on the sliding surface facing away from the end face on the connecting body or on the screw head, on the sliding surfaces

slidably pulled against each other and thereby pressed against the inner surface of the pipe end, whereby the pipe end is connected to the connecting body.

A described in DE-PS35 23155 connecting element differs from the type mentioned by a single expansion sleeve formed sleeve, which is widened by an expansion cone, which is by means of a clamping screw in them expandable. Again, the clamping screw is screwed into a connecting body to which the Speizhülse is present with its front side. By widening this expansion sleeve is pressed against the inner surface of the connecting body to be fastened pipe end.

An analogous connection element is described in DE-OS 3528744 for use as a wall plug. In contrast to DE-PS35 23155 here the wall thickness is made thinner and a second expansion slot with a predetermined breaking point and two diametrically opposite lugs, which dig into the borehole wall, available.

The preparation of the known from CH-PS429317 and DE-PS3523155 connecting elements is complicated and therefore expensive. In order to obtain a slight sliding of the two wedge sleeves on their oblique sliding surfaces, these surfaces had to be processed in a further operation after cutting.

In one described in US-PS 2,643,143, non-generic locking element for telescopically extendable tubes that has a tube end a wedge-shaped approach in a V-shaped continuous section of a aligned with the tube end sleeve with irn unloaded state same outer diameter as the tube. The sleeve is pinned with a clamping bolt which is pulled with a compression spring into the tube interior. The clamping bolt can be moved axially with a lever against the compression spring force. If the compression spring is relieved, the pipe end can be pushed back and forth in a second pipe. Acts the compression spring, the sleeve is pulled with its V-shaped cutout on the approach and thus spread apart, whereby it is pressed against the pipe inner wall of the zwaiten tube. As a result, a displacement of the two tubes against each other to be prevented. The locking element described in US Pat. No. 2,643,143 requires complicated mechanical work on one of the pipes and is only suitable for connecting two pipes.

Further connecting means are known from US-PS 3945743, FR-A2278978, CH-PS488120 and US-PS 3815198.

Object of the invention

The aim of the invention is the further reduction of manufacturing costs and the possibility of a quick installation in securing a stable attachment.

Explanation of the essence of the invention

The invention has for its object to develop an improved connection element of the type mentioned. According to the invention the object is achieved in that the insertable into a bore of a component and clamped by means of clamping elements sleeves of the connecting element are held captive at least approximately flush with each other by a mutual toothing together, the toothing allows an axial Gegeneinanderbewegen and limits an axial movement apart. The sleeves together form a cylindrical shape so that they can be inserted as a whole into a tube. With the claim 4, the object is additionally achieved, the connecting element in such a way that it can be pressed with little effort by means of a clamping screw to the hole or pipe inside, with a uniform pressure of the sleeves to the inner surface without their appreciable deformation is made possible. The inventive method for producing the connecting element is the subject of Ansprucchs 9. Particular embodiments of the invention are set forth in the dependent claims, solved by them further objects and advantages achieved thereby will become apparent from the following explanations of the invention.

embodiments

In the following Ausfnngs examples of the connecting element according to the invention will be explained in more detail with reference to the drawings. Show it

1 is a side view of an attached to a connecting body and clamped in a tube connecting element with two sleeves, the tube is shown in section to better represent the sleeves,

2 shows a diametrically opposite side view of a variant of the connecting element, FIG. 3 shows a rear view of the connecting element shown in FIG. 2, FIG. 4 shows a side view of a further variant of the connecting element, FIG. 5 shows a side view of the variant from FIG , rotated by 90 °, and Figure 6: a side view of the variant of FIG. 4, rotated by 180 °,

8 shows a plan view of the end face of a sleeve after a first bending process in the viewing direction VIII in FIG. 7, wherein the

Elements of stations g.) And h.), Fig. 1: a plan view of the end face of a sleeve after a second to the first subsequent bending operation in

Viewing direction IX in Figure 7, wherein the fully bent sleeves in station h.) Have been removed, Fig. 10: a plan view of the end face emer sleeve after completion of the bending operations in the viewing direction <in Figure 7, Fig. 11: a side view of a variant with toothed, wedge-shaped approach and associated, V-shaped neckline

adjacent sleeves, Fig. 12: a diametrically opposite side view of the sleeves shown in Figure 11 and

Hg. 13: a partial section through a variant of the connecting element, in which the clamping screw is held captive in screwing with a clamping sleeve.

The connecting element 1 shown in Figure 1 has one each with a V-shaped cutout 2 and provided with a wedge-shaped projection 3 cylindrical sleeve 4 and 5 and a clamping element as a clamping screw 7, which in a through thread 9 of a total of three equal diagonal through threads 9,10 and 11 of a formed as a spherical connecting body 13 component is screwed. The connecting element 1 connects a tube 14 as a further component with the adjacent connecting body 13. In order to better show the sleeves 4 and 5, the pipe 14 held by the sleeve 4 is shown cut.

The clamping screw 7 has a narrow coaxial shoulder 15 on the screw head as a holding device, which merges with a bead 16 in the screw shaft 17. The sleeve 5 is bent at its upper end around the bead 16 so that it is rotatable with a clearance fit around the shoulder 15, but not without force application. As a result, the clamping screw 7 is captively connected to the sleeve 5. The thread of the clamping screw 7 is suitable for the threads 9,10 and 11. Both in the screw head as in the screw end is a hexagon socket 18bzw. 19 available. The coaxial extension 15 and the bead 16 are e.g. made by turning the screw head of the clamping screw 7.

The sleeve 4 has on its opposite the neck 2 back, as shown in phantom in Figure 1, a groove 21 into which engages a tongue 23 of the sleeve 5 as an axial guide for both sleeves 4 and 5.

The approach 3 and the entire sleeve 5 are severed by a production conditions, as explained below using the example of a variant of the connecting element 70, conditional slot 24. The approach 3 has three wedge surface pairs 25a, 25b, 26a 26b 27a and 27b, wherein the surfaces a and b of each of the surface pairs 25,26 and 27 is mirror-inverted inclined at the same angle to the approach axis. The pairs of surfaces 25 and 26 are by a pair of edges 29, the edges along the generatrices of the sleeve 4 and 5, and the pairs of surfaces 26 and 27 by a further edge pair 31, the edges of which extend along generatrices of the sleeve 4 and 5, pairs of surfaces 27 a and b runs at an acute angle. The cutout 2 is formed analogously to the approach 3, d. h "he has to the wedge surface pairs 25,26 and 27 also three wedge surface pairs 33,34 and 35 with the same wedge angle, analogous to the Kantenpaaron 29 a / b and 31 a / b by edge pairs 37 a / b and 39 a / b from each other are separated. The edge pairs 29 and 37 and 31 and 39 are separated by gaps 41 a and 41 b and 43 according to a clearance fit. The wedge surfaces 25a / 33a, 25b / 33b, 26a / 34a, 26b / 34b, 27a / 35a and 27b / 35b are connected by a predetermined breaking point, which results from a punching operation of the connecting element 70 analog punching process. By this breaking point, the two sleeves 4 and 5 are captive with each other, i. also connected to the clamping screw 7. Only when tightening the clamping screw 7 break the SoIb. The stronger the neck 3 is pressed into the cutout 2 by the clamping screw 7, the larger the gaps 41 a and 41 b and 43 and the stronger the expansion sleeve 4 is pressed against the inner wall of the tube 14. In the non-compressed state, the diameter of the sleeve 4 is just so great that it can be pushed together with the sleeve 5 large clearance in the tube 14.

The sleeves 4 and 5 are made of Flachmateriai, the shape is, as described below, punched out of flat sheet metal and then bent to the sleeve shape The wedge angle of the wedge surface pairs 33,34 and 35 and the edge pairs 37 and 39 are chosen so large that no self-locking occurs , So after loosening the clamping screw 7 of the Ansät »3 slips out of the cutout 2 independently. As a result, the jamming of the sleeves 4 and 5 is repealed with the pipe inner surface, and the connecting element 1 can be pulled out of the pipe end after complete unscrewing of the clamping screw 7 from the connecting body 13.

Instead of the above-described three wedge surface pairs 25,26 and 27 and 33,34 and 35 can be used at not too high contact pressure only with a Keilfl pair of jets per neck and neck, but then problems can arise in the manufacturing process during bending of the sleeves, since possibly the Sollbruohstellen can already break during the bending process and thus the sleeves can slip apart along their wedge surfaces, which would also no longer be a captive of the individual connecting element parts.

Instead of the two sleeves 4 and 5 three sleeves 50,51 and 52 can be used in a connecting element 54; a side view, analogous to Figure 1, is shown in Figure 2 and a rear view in Figure 3.

The sleeves 50 and 51 have, as shown 'Figure 2, depending on a lug 53 a and 53 b, which engages in a respective cutout 55 a. Two further lugs 65a and 6 lie opposite each other on each of the sleeve end faces of the sleeve 52. The lugs 65a and 65b engage in a respective section ( .t and 67b of the sleeves 50 and 51 as shown in Fig. 3. The lugs 53a and 53b are in Figs Unmounted state analogous to the connecting element 1 with the cutouts 55a and 55b still connected by predetermined breaking points from the manufacturing process .. The two cutouts 55 a and 55 b in the unmounted state by a respective web 57 a and 57 b separated by a longitudinal slot 59 In the tube 14, the webs 57a and 57b break as predetermined breaking points when the clamping screw 7 is tightened, and the two cutouts 55a and 55b are connected to one another via the longitudinal slot 59, and the sleeve 52 is broken.

In Figure 3 is a toothing 61 of the sleeve 52, each with two Vorsprüngun, which are pressed into two recesses of the opposite side, to see. After breaking the webs 57 a and b, the two halves of the sleeve 52 are held together by this toothing 61 such that the two halves against the inner surface of the tube 14 can be pressed, but do not fall apart. The dividing line 63 of the toothing 61 also separates each of the lugs 65a and 65b of the sleeve 52. When mounted in the pipe 14 connecting element 54 are pressed by tightening the clamping screw 7 after breaking the predetermined breaking points, the three sleeves 50,51 and 52 against each other. In this way, the projection 53 a in the cutout 55 a and the neck 53 b, in the cutout 55 b whereby the longitudinal slot 59 of the sleeve 52 are driven apart and the halves of the sleeve 52 are pressed against the inner surface of the tube 14. Similarly, the lugs 65 a and 65 b drive the cutouts 67 a and 67 b of the sleeves 50 and 51 apart, whereby the sleeves 50 and 51 are also pressed against the inner surface of the tube 14. By the four lugs 53a and b and 65a and b is a uniform pressure of the sleeves 51 and 52 to the inner surface of the tube 14, wherein the three sleeves 60,51 and 52 are aligned with each other. Another variant of a connecting element 70 with two sleeves 71 and 72 is shown in FIGS. 4, 5 and 6. Figure 4 shows the two sleeves 71 and 72 analogous to the representation of the two sleeves 4 and 5 in Figure 1. In contrast to the sleeve 4 have the sleeve 71 at its base 74 only two wedge surface pairs 75 a / b and 76a / b and the sleeve 72nd at her neckline 77 only two

Edge pairs 79a / b and 80a / b. The sleeve 72 is also bent at its upper end to the bead 16 of the clamping screw 7, that it is rotatable with a clearance around the shoulder 15, but not removable. The wedge-shaped projection and V-shaped cutout on each sleeve are arranged diametrically opposite one another.

Figure 5 shows the connecting element 70 in a rotated by 90 ° to Figure 4 position. The tube 7 is shown in the illustrations of Figures 4 to 6 cut to better show the sleeves 71 and 72 can. The sleeve 71 has two lugs 81 (a lug 81 can be seen in Figure 5), each in a recess 82 (a recess 82 can be seen in Figure 4) of the sleeve 72 engage.

The lugs 81 and the recesses 82 are approximately symmetrical, but this is not absolutely necessary for their operation described below, arranged for the projection 74 or the cutout 77. There is a gap 84 between the end of the lug 81 and the bottom of the recess 82. The lug 81 widens towards its end and the recess 82 widens towards its bottom. As a result, are approach 81 and recess 82 indissolubly interlocked; but they can be moved towards each other by the width of the gap 84. This width has been chosen so large that it is by an "Oleranz greater than the maximum axial displacement of the sleeves 71 and 72 in the pressing operation described below to the inner surface of the tube. 7

FIG. 6 shows the connecting element 70 in a position rotated through 180 ° with respect to FIG. A longitudinal slot 85 divides a lug 87 of the sleeve 72, whose wedge surface pairs 89a / b and 90 a / b with the same length and the same wedge angle as the wedge surface pairs 75 and 76 are executed. Analogously, the edge pairs are executed in the cutout 92. The longitudinal slot 85 is, as already described in the sleeve 52, in a toothing 93 with two projections and depressions on whose operation is the same as in the sleeve 52.

When tightening the clamping screw 7, the projection 74 drive the sleeve 72 and the projection 87 apart the sleeve 71, whereby both sleeves 71 and 72 are pressed uniformly against the inner surface of the tube 14.

The production of the connecting elements is explained on the connecting element 70, which is made of a sheet steel strip 95, which is unwound from a roll, not shown, in Figure 7. Lateral guide elements of the metal strip 95 are not shown. The individual processing stations are designated in FIG. 7 with the letters a.) To e.). Station f.) Shows the curved sleeves 71 and 72, as shown with respect to the end face of the sleeve 72 in Figure 8. Station g.) Shows a further bending process, wherein the view is shown on the front side of the sleeve 72 in Figure 9; the cutout 77 was cut by severing a web 96. In the station h.) The sleeves 71 and 72 are completely bent and firmly interlocked by means of the toothing 93. Looking at its front side, the sleeve 72 is shown in FIG.

In the processing station a.) In the metal strip 95, the four column 84 and a transport hole 97 (it can also be used several) stamped in which a non-illustrated pin engages to push the sheet metal strip from station to station.

In station b.), The edges of the unwound form 99 and 100 of the sleeves 71 and 72 are punched so that the recess and projections of the toothing 93 and a web 98 to the sheet metal part of the station a.) Stagnate; As a result, the end edge of both of the sleeves 72 (station a.)), and the end edge of one of the sleeves 71 (station b.)) is punched out.

In station c.) The unwound forms 99 and 100 of the two sleeves 71 and 72 are punched so that their parting line is broken as a predetermined breaking point, but both forms are still related.

in station d.) nothing happens, and in station e.) the mold 100 pushed out of the plane of the sheet by the punching operation in station c.) is pressed back again into the plane of the sheet (alignment station); both forms still stick together. The station d.) Is needed to separate the punching operation of station c.) Locally from the alignment station e.).

In station f.) Takes place a first bending process, in which the two forms 99 and 100 are bent to the shape shown in Figure 8 with a view of the end faces. A second bending operation takes place in station g.) To the shape shown in Figure 9, wherein after bending the web 96, as already indicated above, is durcht-nnt.

In station h.), The molds 99 and 100 are bent to the sleeves 71 and 72 and cut from the sheet metal strip 97. When fully round bending the recesses forming a press fit and projections of the teeth 93 are firmly pressed into each other.

Through the course of this process, both sleeves 71 and 72 are made together. Only after the first tightening of the clamping screw 7 in the tube 14 breaks the dividing line between the two sleeves 71 and 72 completely.

Both sleeves 71 and 72 are indissolubly toothed together via the two lugs 81 and recess 82, but axially displaceable so that the sleeves are pushed into each other so far that they are firmly against the inner surface of the tube 14 can be pressed.

Since both sleeves 71 and 72 are mechanically connected across the dividing line during the bending process, they can not be driven apart by their lugs 74 and 87 from the cutouts 77 and 92 - the dividing lines of which are not yet broken.

Instead of making the sleeve 4,5,50,51,52,71, and 72 of steel bands, other elastic material ion can be used. If the connecting element 1 is to be used only once, non-elastic materials can also be used.

Also, the sleeves 4 and 5, and the sleeves 50 and 52, and the sleeves 51 and 52 can be clamped analogous to the sleeves 71 and 72 with lugs (analog 81) and matching recesses (analog 82) to the sleeves captive aligned to keep. Also, the wedge-shaped projections of a sleeve with the associated V-shaped cutouts, as shown in Figures 11 and 12 based on one of the wedge-shaped Anssätzan 74 and 87 and the V-shaped cutouts 77 and 92 of the sleeves 71 and 72 modified wedge-shaped projection 101 and 102 and each of a modified V-shaped cutout 103 and 104 is shown to be toothed with a toothing 105a / b and 106a / b. The task of these teeth 105a / b and 106a / b acts analogously to a predetermined breaking point, as described above, between the edges of the cutout 103 and the projection 101 and the cutout 104 and the projection 102. The predetermined breaking point and toothing have the same task to hold the sleeves together captive and to avoid sliding apart of the sleeves at their wedge surfaces during the bending process. An advantage of the toothing 105a and 106a / b with respect to the predetermined breaking point lies in a greater power transmission capability across the parting line and in the same properties even with repeated use of the connecting element 70. The gearing is not absolutely necessary for the captivity of the sleeves, as this already by the Approaches 81 and 82 is guaranteed.

Instead of attaching a V / ulst 16 on the clamping screw head and thereby bending the adjacent sleeve edge, a clamping element between screw thread and the inner surface of one of the sleeves 4,5,50,51,52,71 or 72 can also be used

become. The clamping element can, for. B is a screwed between the screw thread and sleeve inner surface elastically tensioned perforated disc with a U-shaped cross section, wherein the one leg against the screw thread and the other leg against the inner wall of the sleeves 4, 5,50,52,71 or 72 press. Advantageously, the clamping screw 7 is held captive in one or in both sleeves, so that screwing the screw thread into the connecting body 13 during assembly of the tube 14 on the connecting body 13 is easy to carry out.

Instead of holding the clamping screw 7 captive by means of spring discs or a bent, the screw head adjacent edge of the sleeve, also shown in Figure 13 partially cut clamping sleeve 107 is used. At each end of the sleeve, the clamping sleeve 107 has a respective clamping ring 109a and 109b, which presses against the sleeve 71 and the sleeve 72. The clamping sleeve 107 is seated with a slight interference fit in its narrowed portion 111 on the shaft of the clamping screw 7. The clamping sleeve 107 holds the clamping screw 7 on the one hand, as mentioned above, captive in the two sleeves 71 and 72, andd on the other hand holds the screw thread in the screwed for easy screwing into one of the threads of the connecting body 13.

By the clamping of adjacent sleeves together and by the holder of the clamping screw 7 in one of the sleeves 4, 5,50,51,52,71 or 72 are all parts of the connecting element 1.54 and 70 un. can be loosely connected together in the correct mounting position, and can be pushed as a single component in the pipe end. As a result, the assembly time of the connecting element according to the invention substantially shortens compared with the known connecting elements. The connecting elements 1,54 and 70 according to the invention are easily detachable, that is, the connection can be repeatedly released and used again for connecting other tubes 14 to connecting bodies 13.

Due to the manufacturing method according to the invention, the sleeves 4 and 5, and 50,51 and 52 or 71 and 72 can be extremely inexpensively made of a metal strip Π5. The punching process results in such a good surface do wedge and edge surfaces that their post-processing to improve their sliding together is no longer necessary. Also, the construction and the manufacturing method have been designed such that all sleeves are 4,5,50,51,52,71 and 72 of the connecting element 1,54 or 70 simultaneously produced together and already clamped. Since even the clamping screw 7 is held captive in one of the sleeves 4,5,50,51, 52,71 and 72 in mounting position, the connecting element according to the invention is 1.54 or 70 for quick and easy implementation of pipe connections. The surprisingly good clamping action of the sleeve 4 in the tube 14 and the low clamping force of the clamping screw 7 result from the approach that 3 with distributed over its entire length wedge surface pairs 25,26 and 27, the cut-out 2 apart. As a result, the cylindrical sleeve 4 is widened uniformly over its entire length and thus lies with its entire peripheral surface of the pipe inner wall. This results in a large uniform static friction. The same applies to the lugs 74 and 87 of the sleeves 71 and 72 as well as for the Kiolflae 53 a, 53 b and 65 a, 65 b, wherein in the latter embodiment, instead of several wedge surface pairs at one approach more approaches are available. The low applied clamping force of the clamping screw 7 is due to the fact that only one elastic bending force of the thin-walled sleeves 4 and 5, or 50,51 and 52 and 71 and 72 must overcome werddon. The main part of the clamping force is used to press the sleeves against the inner wall.

Preferably, the connecting element is used in the production of racks, stalls, racks and the like. Tubular constructions. But it can also be used as so-called. Expansion dowel for attaching z. As doors in a borehole of a Tührrahmens be used.

Claims (10)

1. Connecting element for Vorbinden an adjacent component, having at least two oblique sheath edges having sleeves which are axially against each other by means of a central clamping element to be pressed by wedge effect of the oblique sheath edges to the inner hole side of a component, preferably in the interior of a tube, characterized characterized in that the sleeves are held captive at least approximately flush with each other. 2. Connecting element according to claim 1, characterized in that the sleeves are held together by a mutual toothing, which allows an axial Gegeneinanderbewegen and limits an axial movement apart. 3. Connecting element according to claim 1 or 2, characterized in that the sleeves together form a cylindrical shape, so that they can be inserted as a whole in a tube. 4. Connecting element according to claim 1 to 3, characterized in that each of the sleeves on one side a wedge-shaped projection and on the opposite side has a V-shaped cutout, wherein the wedge-shaped projection of a sleeve in the V-shaped cutout of the adjacent sleeve engages and the V-shaped cut the sleeve in the longitudinal direction completely severed or merges into a separating slot or in a separation breaking point, so that each of the sleeves is spread during insertion of the wedge-shaped projection of the adjacent sleeve in their V-shaped cutout. 5. Connecting element according to claims 1 to 4, characterized in that the sleeves (4,5; 50, 51,52; 71,72) from a piece of sheet metal (99,100) are bent so that the flat sheet metal piece (99,100) opposite each other Edge parts lie in the bent state next to each other and form a continuous longitudinal slot (63,85). 6. Connecting element according to claim 5, characterized in that in each case one of two adjacent sleeves (4,5; 50,51,52; 71,72) has on both sides of the longitudinal slot each have a lug portion which under the wedge effect when tightening the clamping element, preferred a clamping screw (7), are pressed together. 7. Connecting element according to claim 6, characterized in that one of the juxtaposed, the longitudinal slot (63,85) through the projection (65a, 65b, 89) forming sheet edge portions of a sheet metal piece (99,100) bent sleeve (52; 71,72 ) has at least one projection which is pressed into a recess of the other sheet edge portion to hold the sheet edge portions interlocked. 8. Connecting element according to claims 1 to 8, characterized in that the clamping element (7) in at least one of the sleeves (4,5; 50,51,52; 71,72) is held captive, preferably centric. 9. A method for producing the connecting element, characterized in that from flat sheet (95) an unwound form (99,100) of adjacent sleeves (71,72) is punched such that the two sleeves in the bending process not along its separation line between the respective wedge-shaped approach and glide apart the corresponding V-neck. , 10. The method according to claim 9, characterized in that at the dividing line of the unwound form (99,100) openings (84) are punched out, the dimensions of which are chosen such that adjacent sleeves (71,72) for spreading axially slidably, but indissolubly interlocked are.