Hinge switch arrangement

Abstract

 A switch (S) is accommodated in a housing (18a) on one hinge leaf member (2) and is operated on relative angular movement of the hinge leaf members (2, 3) about the hinge pin (4) by operating means comprising a plunger (23) cooperating with the periphery of the hinge pin (4) and acting at its other end on a spring loaded rocker lever (20) which in turn acts on the micro switch (S). In use the hinge pin (4) is fast with the hinge member (3) and the periphery of the hinge pin (4) has a recess (27). In a typical mode of use the plunger (23) enters the recess (27) in the operative condition of the switch and door closed position. Immediately the door is opened the plunger (23) rides out of the recess (27) to effect operation of the switch to the inoperative safety condition. For setting purposes and other modes of use the hinge pin (4) is angular adjustable in the hinge member (3) and locked in the required position by the screw (8) and pin (9)

Description

[0001] This invention relates to hinge switch arrangements in which an electrical switch is operated on relative angular movement of the hinge leaf members and the object of the invention is to provide an improved construction of such a hinge switch arrangement primarily for safety or isolation purposes but also capable of other uses such as in a security system.

[0002] A typical practical application of the hinge switch is to the hinged door or cover of a cabinet or other enclosure containing electrical equipment whereby electric current supply to the latter is automatically cut off on the door or cover being opened e.g. by a service or maintenance engineer requiring access to the equipment.

[0003] A further object of the invention is to provide means whereby the hinge switch can be readily adjusted or preset for required operation. Whilst another object is to provide an arrangement in which the possibility of the switch being over ridden is avoided or largely minimised. These and other practical advantages will be apparent from the following disclosure.

[0004] According to the invention a hinge switch arrangement comprises a pair of hinge leaf members pivotally inter­ connected by a hinge pin, one of said hinge leaf members receiving accommodated or enclosed therein or thereon a switch and also carrying switch operating means cooperating with the hinge pin which latter is formed to actuate, or permit actuation, of said switch operating means on rotation relative thereto for corresponding operation of the switch, said hinge pin, in use, being fast with the other of said leaf members whereby turning of the hinge pin therewith on relative angular movement of the hinge leaf members effects or permits said actuation of the switch operating means.

[0005] A practical example of the hinge switch is shown in the accompanying drawings in which:

Figure 1 is an outer face view of the hinge switch, with a switch cover plate removed;

Figure 2 is a corresponding plan view;

Figure 3 is a face view of the cover plate;

Figure 4 is a detail view of the hinge pin per se on an enlarged scale;

Figure 5 is a cross-sectional detail view on the line V-V of Figure 4, and

Figures 6 & 7 are detail enlarged scale side and plan views respectively of a switch operating plunger per se.

[0006] The hinge assembly 1 comprises a hinge body 2 and hinge flap 3, respectively providing the hinge leaf members which are interconnected by a hinge pin 4. In use the body 2 is normally attached to a fixed member, such as a door frame pillar, whereas the flap 3 is fixed to a hinged closure member such as the door of an industrial cabinet or enclosure. For attachment the hinge members 2 and 3 are provided with fixing bolt holes such as 5 but may be otherwise mounted in position of use.

[0007] The body 2 has a knuckle 6 with a vertical pivot bore 7 in which the hinge pin 4 turns, the latter when in use being fast with the flap 3 which has upper and lower knuckles 8 and 9 between which the knuckle 6 is received. Spacers 10 and 11 between the knuckle 6 and the knuckles 8 and 9, respectively, also act as thrust washers. The upper knuckle 8 is split and provided with a cap head screw 12 tightening of which clamps the hinge pin 4 to secure it fast with the hinge flap 3 in an adjusted angular position. The screw 12 engages a peripheral groove 13 in the pin 4 in the manner of a cotter to also provide axial location of the pin 4. The pin 4 has two spaced peripheral grooves 14, positioned within the bore 7, which house O-rings 15 for sealing purposes in respect of the switch operating arrangement which will now be described.

[0008] The rear of the hinge body 2 has a sealing gland 16 for an electrical cable 17, providing appropriate circuit connections to a switch S. The switch S is operated on hinge movement in either direction from a predetermined angular position, which is fully adjustable throughout the full range of hinge movement as later described. The switch S is mounted within a recess 18 in a housing 18a on the hinge body 2, being positioned behind a removable cover plate 19 (Fig. 3) which is normally secured by screws 19a to the housing 18a but is shown removed in Fig. 1 to reveal the switch and switch-operating arrangement. The switch S is shown of the micro-switch type, which would usually control heavy duty isolation switch means such as a coil contactor in effecting safety cut out operation of the latter. The switch S is operated by a lever in the form of a rocker 20 within the recess 18 alongside the switch 2. The rocker 20 pivots on a pivot post 21 under the opposite actions of a return spring 22 and a switch-operating plunger 23 axially slidable in a bore 24 in the body 2. This bore 24 is disposed radially of the hinge pivot bore 7 and extends between the latter and the recess 18.

[0009] The plunger 23, see particularly Figs.6 and 7, has an inner end 25 which seats in the rocker 20 and acts against it, and an outer end 26 shaped to seat in an axial recess or groove 27 formed centrally in the pivot pin 4 midway between the O-ring grooves 14. When the plunger 23 is seated in the groove 27 the return spring 22 moves the rocker 20 to a resting position shown in full lines in Figure 1 in which the switch 2 is in the operative condition in which the contacts C are closed. On relative angular movement of the hinge leaf members 2, 3 and as the pin 4 acting as a pinion turns with the hinge member 3, the plunger 23 rides out of the groove 27 and runs on the plain cylind­rical peripheral surface of the pin 4 during said hinge angular movement. The axial movement of the plunger 23 positively moves the rocker 20, against the return spring 22, sufficiently to operate the switch S to the inoperative contacts open position for safety control by depression of the switch button B. This position of the rocker 20 is shown in broken lines in Fig. 1. So long as the plunger 23 abuts the plain peripheral surface of the hinge pin 4 the rocker 20 is positively held by the plunger 23 against the switch button B and against return movement from such position. Thus the hinge pin 4 actuates or permits actuation of the plunger 23 for switch operation as above described.

[0010] Setting up of the hinge assembly for correct switch operation will now be described, on the basis that it is desired for the switch to be in the operative condition when the door to which the hinge is fitted is closed, and to be operated to the safety inoperative condition when the door is opened. With the hinge 1 mounted on the door (not shown) and the latter is moved to the closed position, and with the clamping screw 12 slackened off, the hinge pin (or pinion) is rotated until the plunger 23 enters and fully seats in the groove 27. (see Fig. 1). To facilitate such rotation the pin 4 is formed with a hexagonal socket 28 at its lower end to receive a hexagonal wrench such as an Allen key. After the correct hinge pin position has been achieved the clamp screw 12 is tightened and the adjustment checked. This is facilitated by the fact that the plunger 23 snaps or clicks into the groove 27. If the switch operates correctly the adjustment is finally locked by drilling the lower knuckle 9 and pin 4, tangential­ly of the latter, to receive a roll pin 29 which prevents any rotation of the pin 4 within the knuckes 8 and 9 so that it is securely fast with the hinge flap 3.

[0011] Once the assembly has been set up in the above manner, rotation of the hinge 1 away from the door closed position immediately causes the plunger 23 to ride out of the groove 27 and move the rocker 20 thus operating the switch S to the inoperative safety condition. This would be the usual mode of operation of the switch in controlling an isolation switch but the micro switch S itself may be arranged to operate for safety cut out and/or warning purposes where heavy current is not involved. The hinge pin 4 is adjustable through 360° and in relation to the full range of angular movement of the hinge members 2, 3 to obtain adjustment of the operation of the switch at any desired hinge position according to operating requirements.

[0012] Angular setting of the hinge pin 4 also depends on the manner in which the hinge is mounted in position of use when the door is closed e.g. in the flat or opened out condition shown in Figures 1 and 2 or when the mounting body 2 is turned at an angle to the flap 3 in the door closed condition.

[0013] The hinge described and shown is capable of relative angular movement of the hinge leaf members 2, 3 through substant­ially 270° and for this purpose the flap 3 is shown recessed at 30 to accommodate the switch housing 18a when the hinge members 2,3 are fully closed together.

[0014] Bushes of anti-friction material such as PTFE (polytetra­fluoroethylene) may be provided about the hinge pin 4 as necessary.

[0015] Incorporation of the switch into the hinge in accordance with the invention permits a compact form of the hinge and avoids the necessity for separate safety provision when opening a cabinet or enclosure door. Moreover, the arrangmeent ensures enforced operation of the switch at the prescribed point of hinge movement, offering the operator no opportunity to modify or over-ride the switching function. In this regard the cover plate 19 should be sealed or locked against unauthorised removal.

Claims

1. A hinge switch arrangement comprising a pair of hinge leaf members pivotally interconnected by a hinge pin, one of said hinge leaf members receiving accommodated or enclosed therein or thereon a switch and also carrying switch operating means cooperating with the hinge pin which latter is formed to actuate, or permit actuation, of said switch operating means on rotation relative thereto for corresponding operation of the switch, said hinge pin, in use, being fast with the other of said leaf members whereby turning of the hinge pin therewith on relative angular movement of the hinge leaf members effects or permits said actuation of the switch operating means.

2. A hinge switch arrangement according to claim 1 wherein the hinge pin is capable of angular adjustment or setting relative to the other of said hinge leaf members for obtaining adjustment of the actuation of the switch operating means and corresponding operation of the switch in relation to the relative angular position of the hinge leaf members.

3. A hinge switch arrangement according to claim 1 or 2 wherein the switch operating means consists of or includes a plunger carried for axial movement by the first mentioned hinge leaf member in or on which the switch is accommodated, one end of the plunger being arranged to effect switch operation and the other end cooperating with the formed periphery of the hinge pin.

4. A hinge switch arrangement according to claim 1, 2 or 3 wherein the switch operating means or plunger cooperates with at least one recess in the periphery of the hinge pin.

5. A hinge switch arrangement according to claim 2, 3 or 4 wherein the plunger operates the switch through a pivoted member or lever.

6. A hinge switch arrangement according to any of the preceding claims wherein the switch operating means is actuated by the hinge pin against the action of return spring loading means.

7. A hinge switch arrangement according to claims 5 and 6 wherein the return spring loading means acts on the pivoted member or lever.

8. A hinge switch arrangement according to any of claims 2 to 7 wherein the other of said hinge leaf members carries locking means for securing the hinge pin fast therewith after angular adjustment or setting of the hinge pin relative to said hinge leaf member.

9. A hinge switch arrangement according to any of the preceding claims wherein the other of said hinge leaf members is recessed to accommodate a switch housing on the first mentioned hinge leaf member when said leaf members are closed together.

10. A hinge switch arrangement according to any of the preceding claims wherein sealing means is provided between the first mentioned hinge leaf member and that part of the hinge pin received by it in order to seal the switch operating means from the exterior.

Drawing