JPH026574Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a structure for preventing rotation of a conductive rod that is fixed through the bushing of a cased switch.

Prior art The conventional anti-rotation structure of the conductive rod of a switch bushing has a protrusion formed on the conductive rod, and the protrusion is directly fitted into a recess provided around the conductor rod insertion hole of the bushing. . Therefore, the load applied to the concave portion of the bushing during tightening is strong and there is a possibility that the bushing may be damaged, and it is particularly troublesome to form the concave and convex portions on the porcelain bushing.

Purpose of the invention This invention was made in order to solve the problems existing in the above-mentioned prior art.In addition to reducing the load applied to the bushing and protecting the bushing, It is an object of the present invention to provide a structure for preventing rotation of a conductive rod in a bushing of a switch, which allows an electrode part to be attached.

Structure of the invention The anti-rotation structure of the conductive rod of this invention has a step part whose diameter increases outwardly in the inner cavity of the bushing, which is fixedly installed so as to penetrate inside and outside the switch case, and further has a stepped part on the inner end surface of the bushing. is provided with a groove for preventing slipping, and the conductive rod inserted into the bushing is provided with a locking flange that locks into the stepped portion, and the inner end of the conductive rod is made of an insulating material and is attached to the inner end surface of the bushing. A shield member that is prevented from slipping by surface contact is inserted, and a detent member that engages with the shield member from the inner end of the conductive rod so that it cannot rotate relative to the conductive rod is also inserted at the inner end of the conductive rod. The shield member and the anti-rotation member are fixed to the inner end surface of the bushing by a nut which is fitted in a non-rotatable manner and is screwed into a threaded portion provided at the inner end of the conductive rod.

Embodiment Hereinafter, an embodiment of this invention will be explained with reference to FIGS. A locking step 4 is formed at the inner end of the cavity 3 and has an enlarged diameter on the outside. A plurality of anti-slip grooves 5 extending radially from the shaft center are formed in the inner end surface of the bushing 2, and engaging step portions 6 are provided on both sides of the inner end.

A conductive rod 7 is passed through the inner cavity 3 of the bushing 2, and a lead wire 8 is caulked to the outer end of the conductive rod 7, and a locking flange 9 is protruded from the outer periphery of the outer end. A threaded portion 10 having a reduced diameter is formed at the inner end of the bushing 2 so as to protrude from the inner end thereof. As shown in FIG. 3, the threaded portion 10 is formed into a drum-shaped cross section so that both sides thereof are flat.

A shield member 11 formed into a cylindrical shape and made of an insulating material such as nonferrous metal, rubber, or synthetic resin is fitted into the inner end of the conductive rod 7. The shield member 11 has a small diameter portion 11 inserted into the inner cavity 3 of the bushing 2.
a, and a large-diameter portion 11b having the same diameter as the inner end of the bushing 2, which is connected to the small-diameter portion 11a via an engaging portion 12 corresponding to the inner end surface of the bushing 2, and an inner bottom surface of the large-diameter portion 11b. has a plurality of engaging protrusions 1
3 is installed protrudingly. Further, in the shield member 11, protrusions 1 that engage with the engaging stepped portions 6 of the bushing 2 are formed from corresponding opposite sides of the engaging portions 12.
1c is formed, and an annular locking protrusion 11d is formed on the engaging portion 12.

Similarly, at the inner bottom of the shield member 11, a detent member 15 is inserted into the inner end of the conductive rod 7 so that it cannot rotate relative to the conductive rod through an insertion hole 14 formed in the same drum shape as the cross-sectional shape of the conductive rod 7. has been done. The anti-rotation member 15 has a transparent engagement hole 16 into which the engagement protrusion 13 of the shield member 11 is inserted, so that it cannot rotate relative to the shield member 11.

A buffer seat 17 is interposed between the locking flange 9 of the conductive rod 7 and the locking step 4, and a nut 18 is inserted into the threaded portion 10 of the conductive rod 7.
are screwed together, and the shield member 11 and the rotation prevention member 15 are connected by the same nut 18 via the spring washer 19.
is fastened to the inner end surface of the bushing 2.

Note that 20 is a bushing fitted into the inner cavity of the bushing, and is inserted into the conductive rod 7 so as to correspond to its outer end.

Now, with the above configuration, the conductive rod 7 is inserted into the inner cavity 3.
While inserting the locking flange 9 from the outside into the bushing 2 so as to attach it to the bushing 2, the locking flange 9 is locked to the locking step 4 through the buffer seat 17. The shield member 11 and the detent member 15, whose mating protrusions 13 are engaged with each other through the engagement hole 16, are connected to the nut 1 through the spring washer 19.
8, the engaging portion 12 of the shield member 11 in which the locking protrusion 11d is formed comes into surface contact with the inner end surface of the bushing 2 in which the anti-slip groove 5 is formed. Rotation is prevented due to low friction. Therefore, the conductive rod 7 is fixed to the bushing 2 so as not to rotate.

In this way, it is possible to control the position of the conductive rod during assembly, such as fitting the protrusion of the conductive rod with the recess provided in the bushing, as seen in conventional anti-rotation methods, and to adjust the shape of the protrusion on the conductive rod or the bushing. There is no need for the trouble of forming a recess into which the protrusion of the conductive rod is fitted, and the tightening work can be performed efficiently. Furthermore, by making the conductive rod 7 unrotatable, the electrode portion can be directly attached and fixed to the conductive rod 7.

Furthermore, by using the shield member 11 consisting of the small diameter part 11a and the large diameter part 11b, the insulation between the live part and the case is strengthened, contributing to the miniaturization of the switch.

In addition, in this embodiment, the protrusion 11 of the shield member 11 that engages with the engagement step 6 of the bushing 2
Also at point c, rotation of the shield member 11 and the bushing 2 is prevented.

In addition, as a configuration similar to this embodiment, for example, instead of the groove 5 provided on the inner end surface of the bushing 2, the inner end surface of the bushing 2 may be made unglazed, or sand may be attached to the front surface to increase friction. Similarly, the shield member 11 and the bushing 2 are prevented from rotating.

Effects of the device As detailed above, this device has a bushing fixed to the switch case so as to penetrate inside and outside, and has a bore into which the conductive rod is inserted, and the diameter of the bore is enlarged on the outside. A groove for preventing slipping is provided on the inner end surface of the bushing, a locking flange is formed on the conductive rod to be inserted into the bushing, and the inner end of the conductive rod is provided with a locking flange that locks on the step. has a drum-shaped cross section, and has a shield member made of an insulating material at the inner end that makes surface contact with the inner end surface of the bushing to prevent slipping, and engages with the shield member from the inner end side of the conductive rod so that it cannot rotate relative to the shield member. Insert the anti-rotation member, and insert the anti-rotation member through a drum-shaped insertion hole that corresponds to the drum-shaped cross section of the inner end of the conductive rod, and screw it into the threaded part provided at the inner end of the conductive rod. By tightening and fixing the shield member and anti-rotation member to the inner end surface of the bushing using a nut, there is no positional restriction during assembly to fit uneven parts, which is the case with conventional anti-rotation methods. The work can be done efficiently, and since it can be tightened and fixed by the frictional resistance caused by surface contact, the inner part of the bushing is prevented by the load applied to the bushing when tightening and fixing, which is the case with conventional detent methods. This eliminates the risk of the end being damaged, and also makes it possible to attach the electrode section directly to the conductive rod.Furthermore, since a shield made of insulating material is used, the insulation between the live part and the case is strengthened. With the aim of
Since it has the effect of contributing to the miniaturization of the switch, it is a practically preferable idea as a structure for preventing rotation of the conductive rod in the bushing of the switch.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view showing an embodiment of this invention.
Figure 2 is a front view of the inner end surface of the bushing, and Figure 3 is A of Figure 1 showing the attached state of the second anti-rotation member.
-A sectional view, FIG. 4 is a front view of the shield member, and FIG. 5 is a side sectional view of the shield member. DESCRIPTION OF SYMBOLS 1...Switch case, 2...Butching, 3...Inner cavity, 4...Locking step, 5...Groove, 6...Engaging step, 7...
Conductive rod, 9... Locking flange, 10... Threaded portion, 11
...shield member, 12...engaging portion, 15...rotation prevention member, 16...engaging hole, 18...nut.

Claims (1)

[Claims for Utility Model Registration] 1. A bushing 2 fixed to the switch case 1 so as to penetrate inside and outside is provided with an inner cavity 3 into which a conductive rod 7 is inserted. A step portion 4 whose diameter is larger on the other side is provided, and an anti-slip groove 5 is provided on the inner end surface of the bushing 2, and a locking flange 9 is provided on the conductive rod 7 inserted into the bushing 2 to lock onto the step portion 4. In addition, the inner end of the conductive rod 7 has a drum-shaped cross section, and the inner end has a shield member 11 made of an insulating material and is in surface contact with the inner end surface of the bushing 2 to prevent it from slipping. On the other hand, a detent member 15 is fitted from the inner end of the conductive rod 7 to prevent relative rotation, and the detent member 15 has a drum-shaped cross section corresponding to the drum-shaped cross section of the inner end of the conductive rod 7. The shield member 11 and the rotation prevention member 15 are connected to each other by a nut 18 that is inserted through the insertion hole 14 and screwed into the threaded portion 10 provided at the inner end of the conductive rod 7.
A structure for preventing rotation of a conductive rod in a switch bushing, characterized in that the conductive rod is fastened and fixed to the inner end surface of the bushing 2. 2. The anti-slip groove is a plurality of grooves 5 formed on the inner end surface of the bushing 2 and extending radially from the axis.A utility model registration claim 1, wherein the anti-slip groove is a plurality of grooves 5 formed on the inner end surface of the bushing 2. structure.