DE20308049U1 - Ring wrench has castellated edge presented to castellated ring adapter with internal profile for removal of worn bolts - Google Patents

Abstract

A ring wrench has a shank (10) with a castellated (13) ring which is presented to a second castellated (22) adapter ring (20). The second ring (20) has an essentially hexagonal inner profile with a series of axial ridges and detents which fit around the worn head (41) of a hexagonal bolt (40).

Description

Key unit

The invention relates to a key unit, and in particular to a key unit comprising a key body and an insert wheel, wherein the insert wheel can be placed on top for perfect engagement with a screw head or a screw nut, so that the key unit can be used even if the screw head is worn.

Generally, a conventional wrench has a rod-shaped wrench body. The wrench body has a hexagonal cavity at one end thereof for receiving a screw head or a screw nut, and its other end, which has a square hole, is intended as a lever end.

However, the design of the above-mentioned wrench is not suitable for engaging a worn screw head, so the application of the conventional wrench is very limited.

In order to eliminate the above-mentioned disadvantages of the conventional wrench, the invention creates a key unit through a structural change that can also be used when the screw head is worn.

The main object of this invention is to provide a wrench unit whose design is easy to use and which can be used even when the screw head is worn.

This object is achieved by the invention described in claim 1; advantageous developments or further embodiments can be found in the features in the subclaims.

The embodiments of the invention are explained in more detail below with reference to the figures. The figures show in detail:

Figure 1 is an exploded view of a first embodiment of a key unit according to the invention;

Figure 2 shows a cross section of the key unit according to the invention according to Figure

i;

Figure 3 is a side view of the key unit according to the invention shown in Figure 1;

Figure 4 is a cross-section of an insert wheel according to the invention of Figure 1;

Figure 5 shows a cross-section of an insert wheel according to the invention with a worn screw head; and

Figure 6 is an exploded view of a second embodiment of a key unit according to the invention.

First, reference is made to Figures 1 and 2. These drawings show an exploded view and a cross-section of a key unit according to the invention. As can be seen from the figures, the key unit according to the invention comprises a key body 10 and an insert wheel 20.

In one end of the key body 10, a cylindrical insert end 12 is defined for holding the insert wheel 20, the opposite openings of which are provided with a plurality of recesses 13, wherein the recesses 13 are designed as a dovetail guide and each have two lateral inclined surfaces 131.

The insert wheel 20 is cylindrical and has a plurality of protruding lugs 22 on the edge of one end which match the recesses 13 of the wrench body 10. An insert 23 is defined in the center of the insert wheel 20 and is designed to engage a screw nut or similar connecting part, the insert being defined as a polygon. On the inner circumference of the insert 23 there are six evenly distributed block recesses 24, three clamping blocks 25 and three support blocks 26, as can be seen in Figures 2 and 4, the clamping blocks 25 and the support blocks 26 being formed one behind the other. In this preferred embodiment, each clamping block 25 is provided with a curved groove on one surface and with a protruding support lug 251 in the center part.

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With reference to Figures 2 and 3, the insert 23 of the insert wheel 20 is placed on a screw 40 for actuation. The screw head 41 of the screw 40 has six edges 411 and six side surfaces 412, the edges 411 pointing towards the block recesses 24 and the side surfaces 412 abutting the support lugs 251 of the clamping blocks 25 and the support blocks 26.

Referring to Figures 2 and 4, when the key body 10 is rotated in the opposite direction, the lugs 22 of the insert wheel 20 press against the inclined bevels 131 of the recesses 13, whereby the insert wheel 20 can be firmly connected to the key body 10.

Because the side surfaces 412 are pressed firmly against the support lugs 251 of the clamping blocks 25 and against the support blocks 26, when the wrench body 10 is pivoted, the screw head 41 of the screw 40 engaged in the insert 23 is thereby rotated.

Figure 5 shows when the insert 23 of the insert wheel 20 is placed on a worn screw head 42, the clamping blocks 25 and the support blocks 26 of the insert wheel 20 engage the side surfaces of the screw head 42 so that the worn screw head 42 of the screw can be rotated by pivoting the wrench body 10.

Referring to Figure 6, a second embodiment according to the invention is shown. In this embodiment, the key unit according to the invention comprises a key body 50 and an insert wheel 60. At one end of the key body 50, an insert end 52 provided with a square nose is defined for holding the insert wheel 60. The cylindrical insert wheel 60 has at one end a square insert hole 61 matching the insert end 52 of the key body 10, with its other end being designed as a hollow insert 62 which is designed for engagement with a screw nut or a similar connecting part. On the inner circumference of the insert 62, six evenly distributed block recesses 24, three clamping blocks 25 and three support blocks 26 are provided.

According to the above descriptions, the key unit according to the invention can also be used for a worn screw head. The construction of the key unit is easy to handle. The object of the invention is thus achieved.

Claims (3)

1. Key unit comprising: a key body and an insert wheel 20 , characterized in :
that an insert end is formed at one end of the key body for holding the insert wheel 20 ,
that one end of the insert wheel 20 can be connected to the insert end of the key body 10 ,
that a polygonal insert 23 is defined in the center of the insert wheel 20 , wherein on the inner circumference of the insert 23 there are several evenly distributed block recesses 24 , several clamping blocks 25 and several support blocks 26 , wherein each clamping block 25 is provided on one surface with a curved groove and in the middle part with a protruding support nose 251 . 2. Key unit according to claim 1, characterized in that the key body 10 has a cylindrical insert end 12 , the opposite openings of which are provided with a plurality of recesses 13 , the recesses 13 being designed as a dovetail guide and each having two lateral inclined surfaces 131 , that the insert wheel 20 has, on the edge of the end connected to the insert end 12 of the key body 10 , a plurality of protruding noses 22 matching the recesses 13 of the key body 10 . 3. Key unit according to claim 1, characterized in that the key body 50 has a square nose at its insert end 52 and that the cylindrical insert wheel 60 has a matching square insert hole 61 at its end facing the insert end 52 of the key body 10 , its other end being designed as a hollow insert 62 .