DE3026475A1 - Expanding screw-anchoring body - acts as trepanning tool when turned - Google Patents

Abstract

The expanding body is for anchoring screws etc. in components of wood, plastic etc., and comprises a tulip-shaped hollow body with a central opening enclosed by a collar and two knife portions on opposite sides at the bottom and bent outwards. When turned, the body acts as a trepanning tool, and it can be arranged so as to have a cutting action when turned in either direction, being expanded merely by axial pressure once it has bored to the desired depth. The ends of the tulip portion can be arranged so as first to expand horizontally and then bent upwards to form anchors.

Description

Expansion body as a self-cutting tool,

when assembling the same as an anchoring platform for self-tapping screws in components.

The invention relates to an expansion body, which initially Task has, through sensible shaping with the appropriate rotation, to itself To be a milling drill and thereby to a precisely defined depth before the pressing process and the material into which it is anchored with the best possible anchoring effect is pressed in, still to be compressed and through a collar-shaped opening and a conical countersink in the center later when connecting two parts, for example with a self-tapping screw, an exact starting point and at the same time an essential to provide improved hold in the material used.

Spreader bodies are known from German utility model 1 885 624 become. This expansion body is intended to screw screws or the like into blind bores to anchor.

They are also known from German utility model 1 825 278 Sleeves that have outwardly protruding tips at their ends, which are also in the walls of bores are driven. The disadvantage of these sleeves is that they are easily reshaped and the connection achieved is only slightly stressable is.

Also known from the German patent 1 230 182 expansion body, which are deformed into a wave-like unfolded sleeve. These require one high pressure for pressing apart and can therefore only be used in highly compacted materials can be used.

Also by the German patent 1 554 506 expansion bodies, the pressed into a limited number of joining materials without pre-drilling can be. Their disadvantage was that the anchoring serves to Surface took place and at the tips sometimes when the pressure begins slipped off and did not or only partially penetrated the material, which resulted in Unwanted downtimes could occur in production.

The present invention is based on the object of the principle to simplify the previously known expanding claws in essential points and economically to improve.

This is first achieved by saving a complex work step, the separate piping with special drills. Thanks to a special shape here the claw itself to the milling drill, whereby the milling process and the subsequent Pressing in can take place one after the other in one operation. The only by the Arrangement of the knife-shaped ends of the claw enabled ring-shaped milling to a desired depth, in the material used let the material core, over which the claw will be pressed immediately afterwards. This is going through the pressing pressure is additionally strengthened and it is delivered later when the self-tapping screw is set an additional strength reserve.

The upper part of the expansion body is rimmed with @@ - like a cube Edges formed so that it moves from a springy sleeve at any time @@@@ are offset as long as the angular momentum is required.

Since after the following complete @@@ press and spreading the spreader its flush part with the central hole and the one underneath compacted material can be used as the basis for self-tapping screw forms, the additional threaded turning part otherwise required here, the "Claw nut" used for many years. This additional claw nut was each Can only be used for one metric dimension and only for certain types of claws anchorable, whereas the subject of the application with its sheet metal collar and the compacted core with the conical embossing in the center is designed so that he different strength tapping screws can serve as an anchoring base.

The simplifications achieved by clermit now also resulted in the possibility of automatic execution of the expansion body via vibrating systems, what the nationalization of large companies in what has not been possible here so far is accommodating.

Claims (4)

Claims: 1. Spreader for anchoring screws, nuts or similar fasteners in components such as wood, plywood, chipboard, plastics i.a. It consists of a tulip-shaped, a central collar-shaped pronounced The hollow part having an opening and can be pressed apart, its oppositely arranged, at least 2 lower ends are bent outwards in the shape of a shovel knife, characterized in that that when a drifting movement is exerted on this hollow part, the same is released acts as a crown drill, which saves work steps and considerable costs. 2. expansion body, according to claim 1, characterized in that the Ends of the tulip-shaped hollow part are shaped so that they can be rotated in any direction, left or right, have the same good milling properties that are necessary in order to penetrate to the desired depth with little effort, from the from a well-guided and centered spreading of the component by means of pure pressure can be done without risk. 3. expansion body, according to claim 1, u.2 characterized in that the at least 4 ends of the tulip-shaped hollow part they are shaped so that already without a counterpart on which the ends are forced to separate when being pressed in (e.g. as before, countersunk head in blind hole) do this, and do so after the initial Advancing into deeper layers of the component while the pressing process continues is a distraction the ends in the horizontal plane and finally anchored upwards. 4. expansion body, according to claim 1,2 and 3, characterized in that the ends of the tulip-shaped hollow part are deformed in pairs opposite to one another so differently may be that during the pressing process in a particular component due to this different Shaping different depths within the material thickness can be detected. This allows you to find the optimal anchorage in each case reach and possibly the risk of a certain layer bursting open by the Avoid excessive pressure in one plane. 50 expansion body, characterized according to claims 1, 2, 3 and 4, that in the center of the expansion body a component corresponding to the hole #, e.g. countersunk screw, Nail pin with head, rivet with head or sleeve nut with head, in one operation can be pressed in directly after milling the ring bore the expansion body itself is done to the desired depth.