ECCENTRIC DEVICE

Abstract: Eccentric device in a connection between two elements (10, 11), comprising a tension rod (14) which is anchored in one element (11) and extends into a bore (13) in the other element (10), and a screw (20) which can be screwed into a threaded transverse aperture (16) in the tension rod through a cross bore (19) in said other element. An externally conical portion (25) is arranged on the screw and the cross bore (19) has a corresponding conical countersink (23) to receive therein the conical portion of the screw. A radial annular shoulder (29) is provided between the small end of the conical portion and the screw shaft allowing the conical portion to be engaged unilaterally with the conical countersink with the axis (18) of the cross bore (19) displaced in relation to the axis (17) of the threaded transverse aperture (16) when the screw is being screwed into the threaded transverse aperture.

Description: ECCENTRIC DEVICE The present invention relates to an eccentric de¬ vice in a connection 6etween two elements, comprising a tension rod which is anchored in one element and ex¬ tends into a bore in the other element, and a screw which can be screwed into a threaded transverse aper¬ ture in the tension rod through a cross bore in said other element, an externally conical portion being arranged on the screw and the cross bore having a corresponding conical countersink to receive therein the conical portion of the screw. A connection of the art referred to above is par¬ ticularly useful for connecting elements of wood, e.g. in furniture, the eccentric device making it possible to tighten the connected elements against each other at the abutment surfaces thereof and also to provide retightening if there should arise a crack between the elements, e.g. due to drying out of the elements if they are made of wood. A connection of the art referred to herein, provided with an eccentric device, is described in one embodiment thereof in the international application No. PCT/SE79/00141 (publi¬ cation No. WO 80/02866) . It is the object of the invention to provide an eccentric device which can be manufactured at low costs and is well suited for mass-production and which can be easily mounted and adjusted - also by an amateur - without using any other tool than a screw driver or a pin spannar such that the connection with this eccentric device can be accepted for inclusion into prefabricated furniture k ts. According to the invention the eccentric device in a connection of the type referred to above is cha¬ racterized in that there is provided between the small end of the conical portion and the screw shaft an annu- DMP WIP lar radial shoulder allowing the conical portion to be engaged unilaterally with the conical countersink with the axis of the cross bore displaced in relation to the axis of the threaded transverse aperture when the screw is being screwed into the threaded transverse aperture. In order to explain the invention in more detail reference is made to the accompanying drawings in whi ch FIG. 1 is a fragmentary side view, partly a cross-sectional view, of two elements with a connection arranged therebetween, comprising an eccentric device which is shown in exploded axial cross-sectional view, FIG. 2 is a view similar to FIG. 1 when the con¬ nection is being mounted by screwing the eccentric device, and FIG. 3 is a view similar to FIG. 1 with the moun¬ ting of the connection completed. In FIG. 1 there are shown two elements to be con¬ nected with each other. One element is designated 10 and this element may comprise e.g. a wood panel or fiber board in a cabinet or a shelf. The other element is de¬ signated 11 and may form e.g. a side wall of the cabinet or shelf and may also comprise a wood panel or fiber board. The element 10 has an edge surface 12 which shall abut a side surface of the element 11 but according to FIGS. 1 and 2 presents a gap in relation to the element 11. From the edge surface 12 a blind hole 13 is drilled, perpendicularly into the element 10, and a blind hole of a corresponding diameter is drilled into the element 11 from the side surface. Said holes are located in the respective elements in such a way that the elements are . positioned in relation to each other as desired when the openings of the holes are opposite to each other and the holes are coaxially alined. A tension bar 14 is inserted into the holes. This bar can be of circu¬ lar cross-sectional form and can be cylindrical. How¬ ever, the bar can also have any other cross-sectional form. Adjacent one end thereof, viz. the end received by the element 11, the tension bar forms a cylindri¬ cal aperture extending perpendicularly through the bar. A pin 15 is driven into the element 11 through this aperture for anchoring the tension bar in the el e ent 11. Adjacent the other end thereof, which is received by the element 10, the tension bar forms a threaded transverse aperture 16, The exis 17 of this aperture is displaced in relation to the axis 18 of a cylindri¬ cal cross bore 19 arranged in the element 10. A screw 20 having a cylindrical head 21 for a hexagonal tap spanner is used for anchoring the ten¬ sion bar 14 in the element 10. This screw forms part of an eccentric device which comprises also a plastic ring 22 having a cylindrical outside surface and being dimensioned to fit rotatably in the bore 19. The ring forms a conical inside surface 23, and the eccentric device comprises a washer 24 having a conical outside surface 25 forming substantially the same cone angle α as the conical inside surface 23 of the ring. The washer has a recess 26 which is large enough to re¬ ceive therein the head of the screw 20, an opening 27 being arranged in the bottom of said recess for the passage of the screw shaft such that the bottom forms around this opening an inside radial annular shoulder 28 providing an engagement surface for the flat lower side of the head 21 , and an outside radial annular shoulder 29. When the ring 22 has been located in the cross bore 19 according to FIG. 2 and the washer 24 has been passed onto the screw 20, this screw is screwed into the threaded aperture 16 so that the conical out¬ side surface 25 of the screw engages the conical inside surface 23 of the ring.22. When the screw is screwed further into the aperture, the tension bar 14 will be displaced axially, the gap between the elements 10 and 11 being eliminated and the axis 17 of the threaded aperture 16 (and the screw 20) being displaced towards the axis 18 of the bore 19. Finally, the condition of FIG. 3 will be obtained wherein the edge surface of the element 10 is tightened against the side surface of the element 11. It is possible to screw the screw 20 further into the aperture for retightening the con¬ nection between the elements. The conical inside surface 23 of the plastic ring 22 can be arranged eccentrical y in relation to the cylindrical outside surface such that there is a further possibility of tightening the elements against each other by rotating the ring in the cross bore 19. In that case a groove, a depression or the like may be arranged in the end surface of the ring, which faces outwards, in order to make possible that the ring is rotated by means of a simple tool, e.g. a screw driver. However, it is possible to exclude the plastic ring 22 from the eccentric device and to arrange the conical surface 23 as a countersink in the bore 19 in the element 10 proper. In order to avoid that a depression arises in the material of the element 10 due to the pressure of the washer 24 against the ele¬ ment 10 at the conical surface 25, the maximum cone angle α of the surface 25 and the countersink (or the surface 23 when the plastic ring 22 is provided) should be 30°, preferably about 15°. The tension bar 14 can be anchored in the element 11 in the same manner as that applied to the element 10, viz. by means of an eccentric device, and it is also possible to arrange the tension bar as part of an angle fitting. The washer 24 may be dispensed with, and in that case the outside conical surface 25 and the outside radial annular surface 29 are formed by the screw head 21. However, an advantage of the disclosed embodiment of the eccentric device according to the invention is that standard screws can be used. A further advantage is that the washer 24 can have a relatively large axial length in order to obtain a large adjustment range, and that the only rotational friction encoun¬ tered when the screw is being tightened, is the fric¬ tion between the head 21 and the shoulder 28. No ro¬ tational friction exists between the washer 24 and the plastic ring 22 and the element 10, respectively. OMPI

Claims: CLAIMS 1. An eccentric device in a connection between two elements, comprising a tension rod which is anchored in one element and extends into a bore in the other element, and a screw which can be screwed into a threaded trans¬ verse aperture in the tension rod through a cross bore in said other element, an externally conical portion being arranged on the screw and the cross bore having a corresponding conical countersink to receive therein the conical portion of the screw, c h a r a c t e ¬ r i z e d in that there is provided between the small end of the conical portion and the screw shaft an annu¬ lar radial shoulder allowing the conical portion to be engaged unilaterally with the conical countersink with the axis of the cross bore displaced in relation to the axis of the threaded transverse aperture when the screw is being screwed into the threaded transverse aperture. 2. An eccentric device as claimed in claim 1, c h a r a c t e r i z e d in that the externally conical portion and the annular radial shoulder are formed by a washer having a recess for receiving the screw head therein, said screw head having a flat lower side engaging a flat bottom surface in the re¬ cess . 3. An eccentric device as claimed in claim 1, c h a r a c t e r i z e d in that said conical countersink in the cross bore is formed by a separate insert mounted in the cross bore. 4. An eccentric device as claimed in claim 3, c h a r a c t e r i z e d in that the countersink of the insert is arranged eccentrically in relation to an outside cylindrical surface of the insert which is rotatably mounted in the cross bore. OMPI

Inventors: STOCKUM INGVAR, STOCKUM, INGVAR
Applicants: STOCKUM DESIGN AB
Application year: 1984
Main classification: F16B12
IPC codes: F16B12