Double-connecting-rod limit switch

Abstract

The utility model relates to the technical field of elevators, in particular to a double-connecting-rod limit switch. Comprising a switch box located on a safety device back plate, a long-strip-shaped hole is formed in the position, located on one side of the switch box, of the safety device back plate in the longitudinal direction, and a first change-over switch and a second change-over switch are arranged in the switch box, rotating shafts of the first change-over switch and the second change-over switch movably penetrate through the switch box and extend towards the long-strip-shaped hole side, an operating rod is fixed to the end of the rotating shaft of the first change-over switch, and the inner end of the operating rod penetrates through the long-strip-shaped hole and is located on the back side of the safety device back plate. And a linkage mechanism is arranged between the operating rod and the driven rod. When the inner end of the operating rod is in contact with the limit iron, the operating rod drives the driven rod to move synchronously through the linkage mechanism, so that the first change-over switch and the second change-over switch are synchronously driven to switch off and cut off an equipment power supply at the same time, and safety protection of a circuit is enhanced through the first change-over switch and the second change-over switch which are connected in parallel.

Description

Technical Field

[0001] The utility model relates to the technical field of elevators, in particular to a double-link limit switch. Background Art

[0002] GB 10055-2007 "Safety Regulations for Construction Hoists" 11.4.3 Limit switches; 11.4.3.1 Rack and pinion construction hoists and wire rope construction hoists for both passenger and cargo must be equipped with limit switches. When the cage exceeds the limit switch, the limit switch must cut off the main power supply to stop the cage. The limit switch is a non-automatic reset type. After it is actuated, it must be manually reset to restart the cage. In order to prevent accidents of cage squatting and roof collapse during operation, existing construction hoists are equipped with upper and lower limit switches and limit switches in the cage. When the limit switch fails, the cage will continue to run. At this time, the limit switch will be actuated to cut off the power supply of the equipment, thereby preventing accidents. The limit switch is a non-self-resetting switch and needs to be manually restored after actuation. The structure of the traditional limit switch is as follows: limit irons are arranged on the top and bottom of the guide frame close to the cage side, a safety device back plate is arranged on the side of the cage close to the guide frame, a switch box is arranged on the safety device back plate, a long hole is opened on the safety device back plate and on one side of the switch box, a conversion switch is arranged in the switch box, the axis of the conversion switch movably passes through the switch box and an operating rod is fixed on the end, the inner end of the operating rod passes through the long hole and is placed between the safety device back plate and the cage, when the limit switch fails and the cage continues to run, when the inner end of the operating rod contacts the limit iron, the operating rod is driven to move, and then the axis of the conversion switch is driven to rotate, cutting off the power supply of the equipment, but for the reliability and safety of the limit switch system, it is expected to set two parallel conversion switches in the switch box, but the linkage structure between the two conversion switches and the limit iron needs to be solved urgently. Utility Model Content

[0003] The utility model aims to solve the above problems, thereby providing a more stable and reliable double-link limit switch.

[0004] The utility model solves the above problems and adopts the following technical solutions:

[0005] A double-link limit switch comprises a switch box located on a back plate of a safety device, a long hole is longitudinally provided on one side of the switch box and on the back plate of the safety device, a first conversion switch and a second conversion switch connected in parallel with a drive motor on the same circuit are arranged in the switch box, the rotating shafts of the first conversion switch and the second conversion switch movably penetrate the switch box and extend toward the long hole, an operating rod is fixed to the end of the rotating shaft of the first conversion switch, the inner end of the operating rod penetrates the long hole and is located on the back side of the back plate of the safety device, a driven rod is fixed to the end of the rotating shaft of the second conversion switch, and a linkage mechanism is arranged between the operating rod and the driven rod.

[0006] Compared with the prior art, the utility model adopting the above technical solution has the following outstanding features:

[0007] When the inner end of the operating rod contacts the limit iron, the operating rod drives the driven rod to move synchronously through the linkage mechanism, thereby synchronously driving the first conversion switch and the second conversion switch to be closed at the same time, cutting off the power supply of the equipment, and enhancing the safety protection of the circuit through the parallel first conversion switch and the second conversion switch.

[0008] As a preferred embodiment, a further technical solution of the utility model is:

[0009] Furthermore, the linkage mechanism includes two connecting rods located on both sides of the rotating shaft of the first conversion switch and the second conversion switch and arranged in parallel, the bottom end of the connecting rod is hinged to the end of the driven rod, and the top end of the connecting rod is hinged to the middle rod body of the operating rod.

[0010] Furthermore, the outer end of the operating rod extends outward to the outside of the front side of the switch box.

[0011] Furthermore, a handle ball head is arranged on the outer end of the operating rod. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a bottom-up three-dimensional structural schematic diagram of an embodiment of the utility model;

[0013] Figure 2 This is a schematic diagram of the main structure of an embodiment of the utility model;

[0014] Figure 3 This is a schematic diagram of a top view of a three-dimensional structure of an embodiment of the utility model;

[0015] The markings in the figure are: safety device back plate 1, long hole 11, switch box 2, operating rod 3, driven rod 4, connecting rod 5, handle ball head 6. DETAILED DESCRIPTION

[0016] The present invention is further described below in conjunction with embodiments, the purpose of which is only to provide a better understanding of the content of the present invention. Therefore, the examples given do not limit the protection scope of the present invention.

[0017] A double-link limit switch, comprising a switch box 2 located on a safety device back plate 1, a long hole 11 is longitudinally opened on the safety device back plate 1 and on one side of the switch box 2, a first conversion switch and a second conversion switch connected in parallel with a drive motor on the same circuit are arranged in the switch box 2, the rotating shafts of the first conversion switch and the second conversion switch movably penetrate the switch box 2 and extend to the side of the long hole 11, an operating rod 3 is fixed to the end of the rotating shaft of the first conversion switch, the middle part of the operating rod 3 is fixed to the end of the rotating shaft of the first conversion switch, and the inner end of the operating rod 3 penetrates the long hole 1 On the back side of the safety device back plate 1, a driven rod 4 is fixed to the end of the rotating shaft of the second conversion switch, and the middle part of the driven rod 4 is fixed to the end of the rotating shaft of the second conversion switch. A linkage mechanism is arranged between the operating rod 3 and the driven rod 4. After the limit iron contacts the inner end of the operating rod 3 on the back side of the safety device back plate 1, it drives the end of the operating rod 3 to swing. The up and down swinging trajectory of the operating rod 3 is located in the long hole 11. The operating rod 3 then drives the rotating shaft of the first conversion switch to rotate, and synchronously drives the driven rod 4 to swing through the linkage mechanism. The driven rod 4 drives the rotating shaft of the second conversion switch to rotate.

[0018] Furthermore, the linkage mechanism includes two connecting rods 5 located on both sides of the rotating shaft of the first conversion switch and the second conversion switch and arranged in parallel. The bottom end of the connecting rod 5 is hinged to the end of the driven rod 4, and the top end of the connecting rod 5 is hinged to the middle rod body of the operating rod 3. The middle section of the operating rod 3, the driven rod 4 and the connecting rod 5 form a hinged quadrilateral. During the swinging process of the operating rod 3, the opposite sides are always balanced, thereby ensuring the synchronous operation of the first conversion switch and the second conversion switch.

[0019] Furthermore, the outer end of the operating rod 3 extends outward to the outside of the front surface of the switch box 2 to prevent the switch box 2 from causing obstruction during manual resetting.

[0020] Furthermore, a handle ball head 6 is provided on the outer end of the operating rod 3 to facilitate operation.

[0021] When the limit switch fails, the cage will continue to run, and the inner end of the operating rod will contact the limit iron on the standard section. The limit iron drives the operating rod to swing, and the operating rod drives the driven rod to move synchronously through the connecting rod, so that the rotating shafts of the first conversion switch and the second conversion switch rotate synchronously, thereby synchronously driving the first conversion switch and the second conversion switch to be closed at the same time, cutting off the power supply of the equipment. Afterwards, the limit switch is reset by the handle ball head on the operating rod, and the safety protection of the circuit is enhanced by the parallel connection of the first conversion switch and the second conversion switch.

[0022] The above description is only a preferred feasible embodiment of the present utility model, and does not limit the scope of rights of the present utility model. All equivalent changes made using the contents of the present utility model specification and its drawings are included in the scope of rights of the present utility model.

Claims

1. A double-link limit switch, comprising a switch box located on a safety device back plate, a long hole is longitudinally opened on one side of the switch box on the safety device back plate, characterized in that: The switch box is provided with a first conversion switch and a second conversion switch which are connected in parallel with the driving motor in the same circuit. The rotating shafts of the first conversion switch and the second conversion switch movably penetrate the switch box and extend toward the long hole. An operating rod is fixed to the end of the rotating shaft of the first conversion switch. The inner end of the operating rod penetrates the long hole and is located on the back side of the back plate of the safety device. A driven rod is fixed to the end of the rotating shaft of the second conversion switch, and a linkage mechanism is provided between the operating rod and the driven rod.

2. The double-link limit switch according to claim 1, characterized in that: The linkage mechanism includes two connecting rods located on both sides of the rotating shafts of the first conversion switch and the second conversion switch and arranged in parallel, the bottom end of the connecting rod is hinged to the end of the driven rod, and the top end of the connecting rod is hinged to the middle rod body of the operating rod.

3. The double-link limit switch according to claim 1, characterized in that: The outer end of the operating rod extends outward to the outside of the front side of the switch box.

4. The double-link limit switch according to claim 3, characterized in that: A handle ball head is arranged on the outer end of the operating rod.

Images