JPS5945842B2 - Strain relief bushing - Google Patents

Description

[Detailed description of the invention] This invention relates to improvements in strain relief bushings.

If electrical cables or fluid hoses must be routed through holes in a metal panel, install plastic bushings in the holes so that the bushings grip the wires or hoses vertically and route the cables or hoses through holes on one side of the panel. It is common practice to prevent tension applied to one side from transferring to the other side.

Another known method is to provide non-circular holes in the panel so that the bushings have complementary external cross-sections so that torques applied to cables or hoses on one side of the panel are not transferred to the back side. . A strain-relieving bushing that can be inserted into a non-circular hole in a panel, through which a cable or hose is passed, and then attached to the hole on one side of the bushing and having a pawl-like shape residing on a flexible finger. It is also known that the teeth exert pressure on the cable or hose to grip them. A disadvantage of such an arrangement is that the gripping force on the cable or hose cannot be removed as desired. It is an object of the present invention to eliminate the above-mentioned disadvantages and to ensure that the cable or hose is simply inserted from one side into a hole in the panel and held firmly in the hole, and that the cable or hose is subsequently inserted into said hole and then fixed. To provide a strain-relieving bushing that firmly grips the cable or hose and can be easily removed as desired.

The object is to provide a hollow body having a non-circular external cross-section inserted into a complementary shaped hole in the panel, an enlarged head for hooking the panel on one side and a retaining member for hooking the panel on the other side; and a strain relief bushing comprising a clamping member arranged to grip the cable or hose through the body; the clamping member being rotatably mounted within the body and having at least one movable fingers, such that when the locking member is partially rotated, the fingers engage the wall of the non-circular hole in the body and apply pressure to the cable or hose. This is achieved by the strain relief bushing of the present invention, which is characterized in that it grips and holds.

Preferably, the strain relief bushing of the present invention as described above comprises:
It has two diametrically opposed fingers that lie opposite to the cable or hose.

Each of the fingers thus has a longitudinal ridge. When gripping the cable or hose, this ridge is fitted into one of the two longitudinal groups in the inner wall of the body to prevent accidental release. Furthermore, it is preferable that the cable or hose can be repositioned or moved by further rotation of the locking member in the same direction so that the gripping state described above can be released. In a further preferred embodiment, the locking member projects from the end (opposite the head) of the shank of the bushing body, and the locking member is confined within the cross-section of the shank at the end. As a result, the bushing can be inserted into the hole in the panel with the locking member installed in the body.

It is also possible to provide a flat portion on the protrusion of the locking member (for example forming a hexagonal periphery), allowing the locking member to be rotated by means of a wrench. The strain-relieving bushing according to the invention can be simply inserted from one side into a hole in a panel and held firmly in the hole, after which a cable or hose can be threaded through the bushing and then tightened. By rotating the stop member, it is possible to grip (the cable, etc.) and release it.

Next, the strain relieving bushing of the present invention will be specifically explained with reference to the accompanying drawings.

The strain relief bushing of the present invention (as shown in FIG. 1) consists of a body 12 and a locking member 14, which are made of nylon (eg, Preferably, but not exclusively, they are manufactured by injection molding of a suitable thermoplastic material such as, but not limited to.

The body 12 of this bushing consists of a shank 16, on the outer periphery of which there are two parallel surfaces connected by an arc, so that the shank can be inserted into a hole 18 with a similar external line in the panel M. When the body 12 is inserted (see FIG. 2), the body 12 will not rotate. At one end of the shank is an enlarged head 20 whose circular flange contacts one side of the panel. The body 12 is hollow with a hole 24 passing through it, and a portion 24/extending from the opposite end of the head 20 is formed by four symmetrically arranged walls.

A pair of opposing walls 26, 26' form part of a cylinder, but are at a distance closer than the outer diameter of the cylinder. Another pair of opposing walls 28, 2Ff form a cylindrical section with a smaller radius and a common axis. In this way, a hole of substantially oval cross-section will be obtained. Facing wall 28
, 28' constitute more than half of the circumferential wall of the hole 24, and a longitudinal groove 30 for fastening is provided in the center as will be described later. At the head end, the bore 24 in the body 12 is of circular cross section and arched outward to provide a gently curved outlet 21.

The minimum diameter of the outlet is smaller than the minimum lateral distance of portion 24. Exit 24' and section 24! In between there is a slot 32 which opens towards the head 20 from one side (the same side as the wall 28) and has a retaining shoulder 34 extending clockwise around the part 24 of the hole. (the purpose of which will become clear later). Each of the walls 28, 2B1 of the shank 16 has a rectangular opening 36, each of which has a head 2
Two elastic retaining members 38, 40 are provided integrally with the end of the opening furthest from zero.

As shown, retainer 38 preferably has one ratchet tooth and retainer 40 has two ratchet teeth; these ratchet teeth project beyond the outer wall of shank 16 and As a result, one pair of teeth (i.e., one on each side of the shank) allows the opposite side of the head of panel M to be latched, and three pairs of teeth allow the body 1 to be easily attached to panels of various thicknesses. It can be inserted and retained within the panel. Other body retention devices may be used in place of the specific shape shown here. The illustrated bushing locking member 14 has a hollow shank 46 and a hexagonal head 48; the shape of the head is determined by the means by which it is rotated and can be varied in various ways. A hole 50 extending rightward through the locking member is substantially cylindrical when the member is in a relaxed state and opens at the head end to form a smooth hole similar to the opening 24 in the body 12. An opening 52 having a curved line is formed. A portion of the shank 46 is constituted by two fingers 54 attached to a longitudinally arranged neck 56.

In the neck, the thickness of the shank material is reduced by longitudinal grooves in the outer wall of the shank. The fingers are fitted into rectangular openings in the wall and are flexible about the neck 56. The fingers 54 are arranged symmetrically about the axis of the locking member, with each finger increasing in thickness from the neck 56.

The outer wall of the netsuku projects from the rest of the cylindrical wall of the shank. The diameter of the cylindrical part of the outer wall of the shank is
The outer ends of the fingers 54 are slightly smaller than the distance between the central portions of the walls 26, 26' of the body when the locking member is relaxed, and the distance between the central portions of the walls 28, 281 is slightly smaller. As a result, by arranging the outer wall of the finger in the center of the walls 28, 28', the locking member can be inserted into the hole 24 of the body without difficulty. When inserted in this manner, the two outwardly directed lugs 60 at the end of the shank 46 opposite the head 48 fit into the slots 32. Here, the ledge is large enough to allow the locking member to pass through the hole 24 and is latched over the retaining shoulder 34 so that the body and the locking member can inadvertently Avoid separation. The head 48 of the clamping member lies entirely within the periphery of the shank 16 of the body, so that the bushing can be inserted into the panel with its two parts (clamping member and body) assembled. . The bushings are assembled as described above and inserted into complementary shaped holes in the panels to receive cables C (as shown in FIG. 3).

The bushing has curved openings at both ends so that it can be conveniently inserted into the panel from either side of the panel. Here, because the opening is bell-shaped, there is no need to reinforce the cable at the point where it emerges from the bushing. After passing the cable C through the pushbutton and adjusting its position in the vertical direction, the locking member 14 is
Rotate vertically clockwise to position the locking member relative to the body as shown in FIG.

(The locking member is shown in the same position in Figure 2, but the cable has been omitted for clarity in that figure.) Rotating the locking member in this manner
8), the fingers 54 are pressed inwardly against each other by the walls 26, 26', and finally the longitudinal drains 62 are inserted into the groups 30 of the body. be located. The fingers thus grip the cable by squeezing it from opposite sides. This locking member prevents the cable from loosening by reverse rotation, but the cable is released by rotating the locking member a further 90 degrees clockwise with the aid of a wrench. (After 909 rotations, the finger returns to its original relaxed state and the cable can be pulled out.)
If desired, as an alternative to the above method, the cable may first be passed through the bushing and then the bushing inserted into the hole in the panel, either before or after rotating the clamping member to grip the cable. can.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the bushing of the present invention shown before the body and the fastening member are assembled.

Claims (1)

Claims: 1. A hollow body with a non-circular external cross-section inserted into a complementary shaped hole in the panel, an enlarged head for hooking the panel on one side and a retaining member for hooking the panel on the other side. , and a clamping member arranged to grip the cable or hose through the cable or hose; the clamping member 14 being rotatably mounted within the body 12; It has at least one movable finger 54, so that when the said locking member 14 is partially rotated, said finger can move the walls 26, 26' of the non-circular hole 24' of the body.
, 28, 28' to apply pressure to grip the cable or hose. 2. The clamping member 14 has two symmetrically arranged fingers that are movable from the relaxed state, so that the clamping member can be rotated by 90° to grip the cable inserted in the relaxed state. The bush according to the above item 1. 3. The fingers 54 form part of the shank 46 of the locking member 14, and the cross-section of the locking member together with the fingers 54 in the relaxed state is smaller than the substantially oval cross-section bore 24' of the body 12. The bushing of item 2 above, which has slightly smaller maximum and minimum dimensions. 4 When the fingers are rotated into the gripping state, the vertical ridges 62 on the fingers 54 engage the group 3 in the body.
0 to prevent inadvertent detachment. 5 The body 12 and the fastening member 14 are molded as separate parts from plastic material, and the hole 20 in the body 12
The bushing of item 1 above is assembled by inserting the locking member 14 therein. 6 The protrusion 60 existing on the fastening member 14 is connected to the body 12
The bushing of clause 5, which engages a retaining shoulder member 34 defined by a slot 32 in the head 20 of the head 20 to prevent inadvertent disengagement. 7. Clause 6 above, wherein the locking member 14 has a head 48 that is completely wrapped around the shank 16 of the body 12, and the body and the locking member can be assembled before inserting the bushing into the hole in the panel. Bushiyu. 8. The holes 24, 50 in the body 12 and the fastening member 14 have gently curved openings 24'', 52 which allow the bushings to be inserted into the panel from either side of the panel as convenient without reinforcing cables or hoses. 1. The bushing of item 1 above, which can be inserted into the bushing.