Limiting device of construction hoist and circuit of limiting device

Abstract

The utility model relates to the technical field of elevators, in particular to a limiting device of a construction elevator and a circuit of the limiting device of the construction elevator, and the limiting device of the construction elevator and the circuit of the limiting device of the construction elevator comprise a fixing mechanism which comprises an installation plate, a fixing support arranged on the installation plate and a fixing transverse rod arranged on the fixing support. The clamping assembly is arranged on the fixed cross rod; the control mechanism comprises a control switch arranged on the mounting plate, and an abutting assembly is arranged between the control switch and the fixed cross rod; and moreover, a limit switch is mounted on the anti-collision rod of the building hoist, and a control circuit is optimized, so that the functions of automatic stop and manual reset in collision are realized, the safety and reliability of the equipment in a complex environment are enhanced, collision accidents are effectively prevented, and the safety of personnel and the equipment is guaranteed.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of lift, especially a limiting device of construction lift and circuit thereof. BACKGROUND

[0002] In the field of building construction, construction lift is a key equipment for vertical transportation of personnel and materials. However, there are potential safety risks in the operation of construction lift, especially when it collides with buildings or other obstacles, which may cause equipment damage, personal injury or even more serious accidents. Therefore, it is crucial to ensure the safe operation of construction lift.

[0003] Traditional construction lift mainly relies on visual judgment and manual operation of the operator to avoid collision, but this method has obvious limitations. The construction site environment is complex, and blocked vision, operator fatigue or negligence may all lead to collision accidents. In addition, the existing lift control system has deficiencies in collision protection, lacking effective automatic stop mechanism and reliable reset function. SUMMARY

[0004] The purpose of this section is to outline some aspects of the embodiments of the utility model and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification and the utility model name to avoid obscuring the purpose of this section, the abstract of the specification and the utility model name. Such simplifications or omissions cannot be used to limit the scope of the utility model.

[0005] In view of the above-mentioned problems of traditional construction lift relying on manual operation to avoid collision, having blocked vision, fatigue and negligence, and lacking automatic stop and reliable reset function, the utility model is proposed.

[0006] Therefore, the purpose of the utility model is to provide a limiting device of construction lift and circuit thereof.

[0007] To solve the above technical problems, the utility model provides the following technical scheme: a limiting device of construction lift, comprising a fixing mechanism including a mounting plate, a fixed support provided on the mounting plate, and a fixed crossbar provided on the fixed support, and a clamping assembly provided on the fixed crossbar; and

[0008] The control mechanism includes a control switch provided on the mounting plate, and a contact component provided between the control switch and the fixed crossbar; and

[0009] Among them, the lower end of the fixed crossbar and the fixed support are rotationally connected, the control switch is installed on the mounting plate, and the control switch is used to control the lifting of the lift.

[0010] As a preferred scheme of the limiting device of the construction hoist, the limiting device comprises a fixed horizontal rod, a mounting plate, a clamping assembly and a resisting assembly.

[0011] As a preferred scheme of the limiting device of the construction hoist, the clamping assembly comprises a clamping rod arranged on the fixed horizontal rod, a clamping hole arranged on the fixed horizontal rod, a clamping bracket arranged on the mounting plate and a reinforcing part arranged on the clamping rod.

[0012] The clamping bracket is arranged on the upper end of the mounting plate, and the clamping bracket is in sliding connection with the fixed horizontal rod.

[0013] As a preferred scheme of the limiting device of the construction hoist, the clamping bracket is fixedly connected with a clamping buckle, the clamping buckle is symmetrically arranged, the clamping rod is provided with a clamping plate, and the clamping plate is matched with the clamping buckle.

[0014] As a preferred scheme of the limiting device of the construction hoist, the reinforcing part comprises an expansion slot arranged on the clamping buckle, an expansion block arranged in the expansion slot, and an expansion spring arranged between the expansion slot and the expansion block.

[0015] The expansion slot is in abutment with the clamping plate.

[0016] As a preferred scheme of the limiting device of the construction hoist, the resisting assembly comprises a resisting inclined block arranged on the fixed horizontal rod, a resisting connecting rod arranged on the control switch, and a connecting piece arranged between the resisting inclined block and the resisting connecting rod.

[0017] The resisting inclined block is matched with the resisting connecting rod, and the resisting connecting rod is in rotary connection with the control switch.

[0018] As a preferred scheme of the limiting device of the construction hoist, the connecting piece comprises a round block arranged on the resisting connecting rod and a directional slot arranged on the resisting inclined block.

[0019] The round block is matched with the directional slot.

[0020] As a preferred scheme of the limiting device of the construction hoist, the round block is provided with an antiskid washer.

[0021] To solve the above technical problems, the utility model provides technical schemes as follows: A kind of construction hoist's circuit, for the limiting device of any one of the construction hoist described in claim, and, main circuit system, including three-phase power supply, circuit breaker, contactor main contact, thermal relay one, motor;Control circuit system, including control power one, stop button, limit switch, start button, contactor coil, thermal relay normally closed contact point, control power two;Wherein, the normally closed contact point of the limit switch is connected in series in the control circuit system, and after the stop button.

[0022] As a preferred scheme of the utility model described a kind of construction hoist's circuit, wherein: the control circuit system further includes fault indicator light, the fault indicator light is installed in parallel at the two ends of the limit switch.

[0023] As a preferred scheme of the utility model described a kind of construction hoist's circuit, wherein: the control circuit system is linked through thermal relay normally closed contact point and the overload protection mechanism of main circuit system, ensure that motor can be parked in time when overload.

[0024] The limiting device of a kind of construction hoist and the beneficial effects of its circuit described in the utility model: the utility model is installed limit switch on construction hoist anti-collision pole and optimizes control circuit, realizes collision automatic shutdown and manual reset function, enhances the safety and reliability of equipment in complex environment, effectively prevents collision accident, guarantees personnel and equipment safety. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the drawings needed to be used in embodiment description will be simply introduced as follows, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor intensity. Wherein:

[0026] Figure 1 It is the overall schematic view of limiting device.

[0027] Figure 2 It is the overall schematic view of clamping assembly.

[0028] Figure 3 It is the partial schematic view of limiting device.

[0029] Figure 4 It is Figure 3 The enlarged view of A in the above-mentioned figure.

[0030] Figure 5 It is the circuit diagram of limiting device. DETAILED DESCRIPTION

[0031] In order to make the above objectives, features and advantages of the present application more apparent, a detailed description of the specific embodiments of the present application will be given below with reference to the accompanying drawings.

[0032] In the following description, a large number of specific details are set forth in order to facilitate a thorough understanding of the present application, but the present application can also be implemented in other ways different from the description, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited by the specific embodiments disclosed below.

[0033] Secondly, the "one embodiment" or "embodiment" referred to herein means that the specific features, structures or characteristics can be included in at least one implementation of the present application. In this specification, "in one embodiment" does not mean the same embodiment, nor does it mean an embodiment that is separate or selectively excluded from other embodiments.

[0034] Embodiment 1

[0035] Reference Figure 1 Figure 4 For the first embodiment of the present application, the embodiment provides a limiting device for construction elevator, which comprises a fixing mechanism 100, a clamping assembly 104, and a fixing plate 101, a fixing support 102 and a fixing crossbar 103.

[0036] Specifically, the mounting plate 101 is the base of the entire limiting device, which is usually installed on the top or side of the elevator cage, and plays the role of fixing and supporting the entire device. The fixing support 102 is installed below the mounting plate 101, and is fixedly connected with the fixing plate. The main function of the fixing support 102 is to install and reinforce the fixing crossbar 103. The fixing crossbar 103 is a key component of the limiting device, which is usually installed at the key position of the elevator, used to prevent the elevator from colliding with other obstacles. The lower end of the fixing crossbar 103 is rotatably connected with the fixing support 102, so that it can have a certain space for movement when it is collided. The clamping assembly 104 is located at the upper end of the fixing crossbar 103, which is used to limit the fixing crossbar 103, to ensure that the fixing crossbar 103 remains stable in the normal working state, and can quickly respond when the collision occurs, so as to facilitate the fixing and limiting of the fixing crossbar 103.

[0037] ​The control mechanism 200 comprises a control switch 201 arranged on the mounting plate 101, and a contact assembly 202 arranged between the control switch 201 and the fixed cross rod 103; and wherein the lower end of the fixed cross rod 103 is rotationally connected with the fixed support 102, and the control switch 201 is arranged on the mounting plate 101 and used for controlling the lifting of the elevator.

[0038] The control switch 201 is arranged on the mounting plate 101 at a position corresponding to the fixed cross rod 103, so that the control switch 201 can be triggered in the first time when the elevator or other obstacles collide, and the control switch 201 can cut off the power supply of the elevator in time to stop the operation of the elevator. The contact assembly 202 is arranged on the control switch 201 and used for increasing the connection between the fixed cross rod 103 and the control switch 201, so as to increase the contact area and the connection strength between the fixed cross rod 103 and the control switch 201, ensure that the fixed cross rod 103 can quickly control the control switch 201 when the collision occurs, and improve the sensitivity and response speed of the control switch 201, so that the limit switch 403 can respond in the first time, thereby improving the sensitivity of the control switch 201.

[0039] Operation process: in the normal working state, when the elevator normally operates, the fixed cross rod 103 is in a free state, the clamping assembly 104 limits the fixed cross rod 103 in the normal working position, the control switch 201 is in a closed state, the control circuit of the elevator is normally powered, and the elevator can normally lift. When the elevator or other obstacles collide with the fixed cross rod 103, the fixed cross rod 103 is impacted and starts to move. The movement of the fixed cross rod 103 triggers the contact assembly 202, the contact assembly 202 transmits the impact force to the control switch 201, the control switch 201 is triggered, the normally closed contact point of the control switch 201 is disconnected, the control circuit of the elevator is cut off, and the elevator stops operating. After the elevator stops operating, the operator needs to check the collision reason and eliminate the fault. After the fault is eliminated, the operator manually resets the fixed cross rod 103 to the normal working position, and the clamping assembly 104 limits the fixed cross rod 103 again.

[0040] Embodiment 2

[0041] Reference Figure 1 - Figure 4 The second embodiment of the utility model is different from the previous embodiment in that the clamping assembly 104 comprises a clamping rod 104a arranged on the fixed cross rod 103, a clamping hole 104b arranged on the fixed cross rod 103, a clamping support 104c arranged on the mounting plate 101, and a reinforcing piece 104d arranged on the clamping rod 104a; wherein the clamping support 104c is arranged on the upper end of the mounting plate 101, the clamping support 104c is slidably connected with the fixed cross rod 103, and the lower end of the clamping rod 104a is matched with the clamping hole 104b.

[0042] The clamping rod 104a is located above the fixed cross rod 103, and the clamping rod 104a and the fixed cross rod 103 are in sliding connection. The end of the clamping rod 104a is matched with the clamping hole 104b. By sliding the clamping rod 104a up and down, the clamping rod 104a is matched with the clamping hole 104b on the fixed cross rod 103, so that the fixed cross rod 103 can be limited. The clamping bracket 104c is installed on the mounting plate 101, and the clamping rod 104a and the clamping bracket 104c are in sliding connection. By reinforcing the reinforcing part 104d on the clamping bracket 104c, the clamping rod 104a can be fixed, so that the clamping rod 104a cannot fall off the fixed cross rod 103, thereby failing to achieve limiting reinforcement.

[0043] The clamping bracket 104c is fixedly connected with the clamping buckle 104e, and the clamping buckle 104e is symmetrically arranged. The clamping rod 104a is provided with the clamping plate 104f, and the clamping plate 104f is matched with the clamping buckle 104e.

[0044] Specifically, the clamping buckle 104e on the clamping bracket 104c is symmetrically arranged up and down, and the clamping buckle 104e is matched with the groove on the clamping plate 104f. By sliding the clamping rod 104a, the clamping plate 104f is buckled on the corresponding position of the clamping buckle 104e, so as to realize the separation and insertion of the clamping rod 104a and the clamping hole 104b.

[0045] The reinforcing part 104d includes an expansion slot 104d-1 provided on the clamping buckle 104e, an expansion block 104d-2 arranged in the expansion slot 104d-1, and an expansion spring 104d-3 connected between the expansion slot 104d-1 and the expansion block 104d-2. The expansion slot 104d-1 is in abutment with the clamping plate 104f.

[0046] The expansion block 104d-2 is symmetrically arranged, and the adjacent expansion blocks 104d-2 are connected by the expansion spring 104d-3. The side of the expansion block 104d-2 away from the expansion spring 104d-3 is in arc shape. This design can realize simple limiting of the clamping plate 104f, prevent separation of the clamping buckle 104e and the clamping plate 104f caused by slight shaking of the outside world, and further realize limiting of the clamping rod 104a. At the same time, when the clamping plate 104f is manually pulled, a slight external force can realize separation.

[0047] The remaining structures are the same as those in Embodiment 1.

[0048] Operating Procedure: Under normal operating conditions, the locking lever 104a is positioned above the fixed crossbar 103, with its end inserted into the locking hole 104b on the fixed crossbar 103, thus limiting the fixed crossbar 103 to its normal operating position. When it is necessary to release the fixed crossbar 103, the operator manually pulls the locking plate 104f. Due to the action of the telescopic slider 104d-2 and the telescopic spring 104d-3, the locking plate 104f separates from the upper and lower positions of the locking buckle 104e. The locking lever 104a slides upward under the guidance of the locking bracket 104c, and its end disengages from the locking hole 104b on the fixed crossbar 103. At this time, the fixed crossbar 103 loses its limiting position and can move within a certain range. The device moves freely within the device. After troubleshooting or completing related operations, the operator manually resets the fixed crossbar 103 to its normal working position. The locking lever 104a slides downward under the guidance of the locking bracket 104c, and its end is reinserted into the locking hole 104b on the fixed crossbar 103. The telescopic spring 104d-3 provides elastic force, making the locking plate 104f and the locking buckle 104e fit tightly together, further enhancing the stability of the locking lever 104a. The locking plate 104f is re-locked in the upper and lower positions of the locking buckle 104e. Through the action of the reinforcement 104d, the stable connection between the locking lever 104a and the locking hole 104b is ensured, restoring the limit on the fixed crossbar 103.

[0049] Example 3

[0050] Reference Figure 1 - Figure 4 This is the third embodiment of the present invention. Unlike the previous embodiments, the following features are distinguished: the contact component 202 includes a contact ramp 202a mounted on the fixed crossbar 103, a contact link 202b mounted on the control switch 201, and a connector 202c between the contact ramp 202a and the contact link 202b; wherein the contact ramp 202a and the contact link 202b are adapted to each other, and the contact link 202b and the control switch 201 are rotatably connected; the connector 202c includes a circular block 202c-1 mounted on the contact link 202b, and a directional groove 202c-2 formed on the contact ramp 202a; wherein the circular block 202c-1 and the directional groove 202c-2 are adapted to each other; and an anti-slip washer is provided on the circular block 202c-1.

[0051] The contacting inclined block 202a is installed on the side of the fixed crossbar 103. The contacting inclined block 202a is inclined so that it can come into contact with the round block 202c-1, so that the round block 202c-1 can be squeezed and slide along the inclined surface of the contacting inclined block 202a, thereby realizing the opening and closing of the control switch 201.

[0052] Specifically, the abutting link 202b is rotationally connected with the control switch 201, and the upper end of the abutting link 202b is rotationally connected with the abutting link 202b. The section of the round block 202c-1 is circular, and the round block 202c-1 is abutted with the abutting inclined block 202a, so that the abutting link 202b rotates on the control switch 201, and the opening and closing of the control switch 201 can be realized.

[0053] Further, the abutting inclined block 202a is provided with a directional sliding groove 202c-2, and the surface of the round block 202c-1 is provided with a non-slip washer. The round block 202c-1 slides in the directional sliding groove 202c-2 to provide guidance for the movement of the round block 202c-1, and prevent the round block 202c-1 from falling off the abutting inclined block 202a. The non-slip washer added on the round block 202c-1 can increase the friction between the round block 202c-1 and the directional sliding groove 202c-2, and further prevent the round block 202c-1 from separating from the abutting inclined block 202a when sliding.

[0054] The remaining structure is the same as that of Example 2.

[0055] Operation process: when the elevator or other obstacles collide with the fixed cross rod 103, the fixed cross rod 103 is impacted and starts to move, and the movement of the fixed cross rod 103 drives the abutting inclined block 202a to move, and the abutting inclined block 202a contacts the round block 202c-1 on the abutting link 202b. Because the abutting inclined block 202a is inclined, the round block 202c-1 is pressed by the inclined surface of the inclined block, and the round block 202c-1 slides in the directional sliding groove 202c-2 and moves along the inclined surface of the abutting inclined block 202a. The effect of the non-slip washer makes the round block 202c-1 stable during sliding and prevents it from separating from the directional sliding groove 202c-2. The round block 202c-1 slides in the directional sliding groove 202c-2 and moves along the inclined surface of the abutting inclined block 202a. The effect of the non-slip washer makes the round block 202c-1 stable during sliding and prevents it from separating from the directional sliding groove 202c-2.

[0056] Example 4

[0057] Referring to 5, for the third embodiment of the utility model, different from the above embodiments is: main circuit system 300, including three-phase power supply 301, circuit breaker 302, contactor main contact 303, thermal relay one 304, motor 305;Control circuit system 400, including control power supply one 401, stop button 402, limit switch 403, start button 404, contactor coil 405, thermal relay normally closed contact point 406, control power supply two 407;Among them, the normally closed contact of limit switch 403 is connected in series in control circuit system 400, and is located after stop button 402;Control circuit system 400 further includes fault indicator, and the fault indicator is installed in parallel at both ends of limit switch 403;Control circuit system 400 is linked with the overload protection mechanism of main circuit system 300 through thermal relay normally closed contact point 406, to ensure that motor 305 can be stopped in time when overload.

[0058] I. Normal start

[0059] Start operation:

[0060] The operator presses start button 404 (normally open button).

[0061] Start button 404 is closed, and current flows to contactor coil 405 through control circuit.

[0062] Contactor coil 405 is powered, and contactor main contact 303 is closed.

[0063] Three-phase power supply 301 is connected to motor 305 through circuit breaker 302, contactor main contact 303 and thermal relay, and motor 305 starts running.

[0064] At the same time, the auxiliary normally open contact of contactor coil 405 is closed, forming a self-locking loop, keeping the circuit powered, even if the start button 404 is released, the motor 305 can continue to run.

[0065] II. Stop condition

[0066] Manual stop:

[0067] The operator presses stop button 402 (normally closed button).

[0068] Stop button 402 is disconnected, cutting off the control circuit, and contactor coil 405 loses power.

[0069] Contactor main contact 303 is disconnected, cutting off the power supply of motor 305, and motor 305 stops running.

[0070] Collision triggers stop:

[0071] When the elevator or other obstacles collide with the anti-collision rod, the limit switch 403 (normally closed button) on the anti-collision rod is triggered.

[0072] The normally closed contact of limit switch 403 opens, cutting off the control circuit, and the contactor coil 405 loses power.

[0073] The contactor main contact 303 opens, cutting off the power supply to the motor 305, and the motor 305 stops running.

[0074] III. Reset Mechanism

[0075] Limit switch 403 is reset:

[0076] After excluding the collision reason, the limit switch 403 is reset, and its normally closed contact is closed again.

[0077] However, at this time the motor 305 will not automatically restart, and the operator needs to manually press the start button 404 to restart the motor 305.

[0078] This manual reset mechanism avoids the risk of secondary collision caused by automatic restart, ensuring that the equipment runs in a safe state.

[0079] IV. Safety Verification and Extended Function

[0080] Fault safety mechanism:

[0081] If the limit switch 403 or the line fails (such as a broken wire), the control circuit will automatically disconnect, forcing the machine to stop.

[0082] This design ensures that the elevator stops running in time in any abnormal situation, preventing equipment damage and personal injury.

[0083] Multiple limit switches 403 extension:

[0084] When installing limit switches 403 at multiple anti-collision points, connect the normally closed contacts of all limit switches 403 in series.

[0085] When any limit switch 403 is triggered, the control circuit will be disconnected, ensuring that the elevator stops running.

[0086] This design enhances the safety of the system, ensuring that the machine stops running in time when a collision occurs at any anti-collision point.

[0087] Fault indication:

[0088] Parallel fault indicator lights are connected across the limit switch 403.

[0089] When the limit switch 403 is triggered, the fault indicator light turns on, prompting the operator that the equipment is in a stopped state.

[0090] This design facilitates the operator to quickly find the fault location and take timely measures.

[0091] V. Wiring Steps

[0092] The normally closed contact of the limit switch 403 is connected in series in the control circuit after the stop button 402.

[0093] The normally closed contact of the limit switch 403 is connected in series in the control circuit after the stop button 402.

[0094] Ensure that the limit switch 403 can reliably cut off the control circuit in the event of a collision.

[0095] Wiring Check:

[0096] Ensure that all connections are secure, use wire labels to avoid misconnections.

[0097] Check if the control circuit connections are correct, ensure that the connections between components meet the design requirements.

[0098] Function Test:

[0099] Manually trigger the limit switch 403 to verify that the motor 305 stops immediately.

[0100] Check if the fault indicator light is on, indicating that the device is in a shutdown state.

[0101] Verify the manual reset function, ensure that after troubleshooting, the motor 305 needs to be restarted by manually pressing the start button 404.

[0102] Six, Matters Needing Attention

[0103] Regular Maintenance:

[0104] Regularly check the sensitivity and contact state of the limit switch 403 to prevent rust or mechanical jamming.

[0105] Ensure that the limit switch 403 can reliably trigger in the event of a collision and promptly cut off the control circuit.

[0106] Precautions:

[0107] Install a protective cover for the limit switch 403 to prevent damage from falling objects.

[0108] Ensure that the limit switch 403 can still work normally in harsh environments, improving the reliability of the system.

[0109] Emergency Stop:

[0110] Keep the original emergency stop button as a multiple safety guarantee.

[0111] In an emergency, the operator can quickly stop the machine through the emergency stop button to ensure the safety of the equipment and personnel.

[0112] The remaining structure is the same as that of Example 3.

[0113] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and all should be covered in the scope of the claims of the present application.

Claims

1. A position limiting device for a construction elevator, characterized by: The utility model relates to a kind of fixing mechanism and control mechanism, including, The fixing mechanism (100) includes mounting plate (101), fixed support (102) being arranged on the mounting plate (101), and fixed crossbar (103) being arranged on the fixed support (102), clamping assembly (104) being arranged on the fixed crossbar (103);And, The control mechanism (200) includes control switch (201) being arranged on the mounting plate (101), and the control switch (201) with the fixed crossbar (103) between it is provided with resistance component (202);And, Wherein, the lower end of the fixed crossbar (103) and the fixed support (102) are rotatably connected, the control switch (201) is installed on the mounting plate (101), and the control switch (201) is used to control the lifting of the elevator.

2. A position limiting device for a construction elevator as defined in claim 1, wherein: The clamping assembly (104) includes clamping lever (104a) being arranged on the fixed crossbar (103), clamping hole (104b) being opened in the fixed crossbar (103), clamping support (104c) being arranged on the mounting plate (101), and reinforcing member (104d) being arranged on the clamping lever (104a); Wherein, the clamping support (104c) is installed on the upper end of the mounting plate (101), and the clamping support (104c) and the fixed crossbar (103) are slidably connected, and the lower end of the clamping lever (104a) is matched with the clamping hole (104b).

3. A position limiting device for a construction elevator as defined in claim 2, wherein: The clamping support (104c) is fixedly connected with clamping buckle (104e), the clamping buckle (104e) is symmetrically arranged, the clamping lever (104a) is provided with clamping plate (104f), and the clamping buckle (104e) is matched with the clamping plate (104f).

4. A position limiting device for a construction elevator as defined in claim 3, wherein: The reinforcing member (104d) includes telescopic sliding slot (104d-1) being opened in the clamping buckle (104e), telescopic sliding block (104d-2) being arranged in the telescopic sliding slot (104d-1), and the telescopic sliding slot (104d-1) and the telescopic sliding block (104d-2) are connected by telescopic spring (104d-3); Wherein, the telescopic sliding slot (104d-1) is in contact with the clamping plate (104f).

5. A position limiter for a construction elevator as set forth in claim 1, characterized in that: The resistance component (202) includes resistance inclined block (202a) being arranged on the fixed crossbar (103), resistance connecting rod (202b) being arranged on the control switch (201), and connecting piece (202c) being arranged between the resistance inclined block (202a) and the resistance connecting rod (202b); Wherein, the resistance inclined block (202a) and the resistance connecting rod (202b) are matched, and the resistance connecting rod (202b) and the control switch (201) are rotatably connected.

6. A position limiting device for a construction elevator as defined in claim 5, wherein: The connecting piece (202c) includes round block (202c-1) being arranged on the resistance connecting rod (202b), and directional sliding slot (202c-2) being opened in the resistance inclined block (202a); The round block (202c-1) is matched with the directional chute (202c-2).

7. A position limiting device for a construction elevator as defined in claim 6 wherein: The round block (202c-1) is provided with a non-slip washer.

8. A circuit of a construction hoist for the position limiting device of any one of claims 1-7, characterized in that: a main circuit system (300) comprising a three-phase power supply (301), a circuit breaker (302), a contactor main contact (303), a thermal relay I (304), and a motor (305); a control circuit system (400) comprising a control power supply I (401), a stop button (402), a position limiting switch (403), a start button (404), a contactor coil (405), a thermal relay normally closed contact (406), and a control power supply II (407); wherein the normally closed contact of the position limiting switch (403) is connected in series in the control circuit system (400) and is located after the stop button (402).

9. A construction hoist circuit according to claim 8, wherein: The control circuit system (400) further comprises a fault indicator light which is connected in parallel across the position limiting switch (403).

10. A construction hoist circuit according to claim 9, wherein: The control circuit system (400) is linked with the overload protection mechanism of the main circuit system (300) through the thermal relay normally closed contact (406) to ensure that the motor (305) can be stopped in time when overloaded.

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