Moving limit detection switch

Abstract

To provide a travel limit detection switch for a movable work platform, which is suitable for a scaffolding-free installation method of an elevator.SOLUTION: A mechanical travel limit detection switch 100 is used in a scaffolding-free installation method of an elevator, and detects when a movable work platform, which moves up and down within a hoistway, approaches an obstacle at a destination of movement, such as a ceiling or pit bottom of the hoistway. The switch is provided with a first clamp 110 and a second clamp 120 as attachment means that can be detachably attached to a member located within the hoistway, namely, a safety fence of the movable work platform or a guide rail that guides the vertical movement of the movable work platform.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a movement limit detection switch, and particularly to a movement limit detection switch used in a method for constructing an elevator without a scaffold.

Background Art

[0002] In elevator installation work, which is part of building construction work, a scaffolding method and a scaffolding-free method are known as work methods for installing in-hoistway equipment in a hoistway.

[0003] The scaffolding-free method is a method that does not use a framework scaffold like the scaffolding method, but uses a moving work floor that can move up and down in the hoistway, and is adopted for the installation work of elevators with medium and high hoisting strokes (Patent Document 1).

[0004] As the moving work floor, the car frame of the elevator to be installed is used. That is, the state in which components that interfere with elevator installation work, such as side panels and car doors, are removed from the installed car. In other words, basically, the car in the state before attaching the components is used as the moving work floor.

[0005] In addition, in order to install in-hoistway equipment above the top floor, a work floor (hereinafter referred to as the "upper work floor") is also provided on the upper part of the car frame on the moving work floor. In addition, a safety fence is provided to ensure safety when working on the upper work floor.

[0006] That is, the moving work floor is a car in a state where the minimum necessary components for elevator installation work, such as an upper and lower floor for workers to board, the above-mentioned safety fence, and a simple operation button device for giving hoisting instructions, are attached to the car frame.

[0007] In the scaffolding-free method, a worker who has boarded the above-mentioned mobile work floor operates the above-mentioned operation button device to raise and lower the mobile work floor in the hoistway and install the hoistway equipment. At this time, for example, it is assumed that the worker is distracted by operating the operation button device, exceeds the upper limit, and is pinched between the hoistway ceiling and the mobile work floor. Patent Document 2 discloses an alarm device that detects that the car has approached the ceiling of the hoistway by a predetermined distance in the maintenance work of the existing elevator, although it is not the scaffolding-free method (paragraphs

[0030] and

[0031] of Patent Document 2, FIG. 4).

[0008] The alarm device has a laser distance meter provided in a housing 10 fixed on the car 2. Then, it is configured to irradiate an invisible laser beam toward the ceiling of the hoistway, receive the reflected light, and measure the distance to the ceiling of the hoistway of the car 2.

[0009] However, if the above-mentioned alarm device is used in the scaffolding-free method which is part of the construction work, the laser irradiation part is likely to be damaged by dust or the like, and for this reason, there is a risk that it will not operate properly.

[0010] On the other hand, a mechanical switch for detecting the upper limit of the car's ascent is described in Patent Document 3 (FIGS. 1 and 10 of Patent Document 3). The switch described in Patent Document 3 (hereinafter referred to as "conventional switch") is also not used in the scaffolding-free method, but is used during the maintenance inspection of the existing elevator.

[0011] The conventional switch is provided at the tip of a foldable protruding column 14 rotatably supported above the safety handrail 12. The conventional switch includes a contact rod 14n and a detection switch 14g that are displaceable in the vertical direction (FIG. 10 of Patent Document 3). A roller 14r is provided at the tip of the contact rod 14n, and a cam 14g is provided in the middle.

[0012] When the contact rod 14n is erected and the cage 1 approaches the ceiling of the hoistway, the roller 14r collides with the ceiling, causing the contact rod 14 to be pushed down. The cam 14 presses the detection switch 14g, thereby detecting the upper limit of the cage 1 (paragraph

[0011] of Patent Document 3).

Prior Art Documents

Patent Documents

[0013]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0014] However, the ceiling of the hoistway has unevenness due to the erection of building beams, and its erection position also varies depending on the building. Therefore, in the conventional switch fixed at a certain position of the safety handrail 12, the roller 14r may come into contact with the concave portion of the ceiling. In this case, the convex portion of the ceiling and the cage 1 will approach each other beyond a safe distance.

[0015] In view of the above problems, an object of the present invention is to provide a movement limit detection switch suitable for a scaffolding-free construction method that can reliably detect the movement limit of a mobile work floor with respect to the ceiling of the hoistway as much as possible regardless of the shape of the ceiling of the hoistway.

Means for Solving the Problems

[0016] To achieve the above object, the moving limit detection switch according to the present invention is a mechanical moving limit detection switch that is used in the scaffolding-free method of an elevator and detects that a moving work floor that moves up and down in a hoistway has approached an obstacle at the destination. It is characterized by having mounting means that can be detachably attached to a member existing in the hoistway.

[0017] Further, the moving work floor includes a car frame, an upper work floor provided on the upper part of the car frame, and a safety fence for ensuring the safety of workers when working on the upper work floor. The member is the safety fence, and the mounting means includes a mounting portion for the safety fence that can be detachably attached to the safety fence. The obstacle is the ceiling of the hoistway.

[0018] Alternatively, the member is a guide rail that guides the lifting and lowering of the moving work floor, and the mounting means includes a mounting portion for the guide rail that can be detachably attached to the guide rail. The obstacle is the bottom of the pit of the hoistway.

[0019] Furthermore, the mounting means includes both the above-mentioned mounting portion for the safety fence and the above-mentioned mounting portion for the guide rail.

[0020] It also has a direct-acting cam that includes a guide surface and slides in the vertical direction, a biasing member that elastically biases the direct-acting cam upward, and a limit switch that includes an actuator. When the moving work floor is attached to the safety fence and moves upward, the upper end of the direct-acting cam abuts against the ceiling, and the direct-acting cam slides downward against the biasing force of the biasing member, so that the guide surface abuts against the actuator and the limit switch is turned on. When the moving work floor is attached to the guide rail and moves downward, the upper end of the direct-acting cam abuts against a part of the moving work floor, and the direct-acting cam slides downward against the biasing force of the biasing member, so that the guide surface abuts against the actuator and the limit switch is turned on, thereby detecting that the moving work floor has approached the ceiling or the bottom of the pit.

[0021] Furthermore, the movement limit detection switch is electrically connected to a control panel that controls the lifting movement of the movable work floor. The control panel prohibits the upward movement of the movable work floor by controlling the rotation of the prime mover, which is the power source for the lifting of the movable work floor, to stop while the limit switch of the movement limit detection switch attached to the safety fence is in the on state, and prohibits the downward movement of the movable work floor by controlling the rotation of the prime mover to stop while the limit switch of the movement limit detection switch attached to the guide rail is in the on state. The linear cam has a length sufficient for the guide surface to continue to contact the actuator at least from the start of the stop control until the movable work floor that moves up and down due to its inertia stops.

Advantages of the Invention

[0022] Since the movement limit detection switch according to the present invention having the above configuration is mechanical, it is not affected by dust or the like, and thus can be suitably used for the scaffolding-free method of elevators which is carried out as part of construction work.

[0023] In addition, since it has attachment means that can be detachably attached to members existing in the hoistway, for example, when attaching to a safety fence that the movable work floor usually has, it can be attached to a predetermined position of the safety fence in consideration of the unevenness of the hoistway ceiling. Therefore, without causing the above-described problems of the conventional switch, it is possible to detect the movement limit of the movable work floor with respect to the hoistway ceiling as reliably as possible.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0025] Hereinafter, the present invention will be described based on embodiments with reference to the drawings. Note that in each figure, the scales between components are not necessarily unified. <Overall Configuration of Elevator> Fig. 1 is a perspective view showing a schematic configuration of a machine roomless elevator 10 completed through a scaffolding-free method. In Fig. 1, the illustration of safety fences 70, 72, etc. to be described later is omitted.

[0026] The machine roomless elevator 10 (hereinafter simply referred to as "elevator 10") has a car 14 with a substantially rectangular parallelepiped shape, with an entrance 12 provided on one side. The entrance 12 is provided with a center-opening double-leaf car door 16. Above the car door 16, a car door device 17 for driving the opening and closing of the car door 16 is installed.

[0027] The elevator 10 has a main rope 34 that is strung in this order on a suspension car 18 attached to the outer bottom of the car 14, a first return pulley 22 provided at the upper part of the hoistway 20, a drive sheave 26 of a hoisting machine 24 provided at the lower part of the hoistway 20, a second return pulley 28 provided at the upper part of the hoistway 20, and a suspension car 32 of a counterweight 30. The first end 34a of the main rope 34 is attached to a high-level beam 36 provided at the upper part of the hoistway 20, and the second end 34b is attached to a high-level beam 38 also provided at the upper part of the hoistway 20.

[0028] As can be seen from the above configuration, the elevator 10 is a type of elevator that does not suspend the car 14 directly above it (there is no main rope directly above).

[0029] In the hoistway 20, there are also provided car guide rails 40, 42 for guiding the car 14 in the vertical direction and counterweight guide rails 44, 46 for guiding the counterweight 30 in the vertical direction, which are respectively erected.

[0030] A control panel 50 that controls a prime mover (not shown in FIG. 1) for driving the hoisting machine 24, the car door device 17, etc., to realize smooth operation of the elevator 10 is attached to the left side wall 20L near the pit PT.

[0031] In the elevator 10 configured as described above, when the hoisting machine 24 is driven and the drive sheave 26 is rotated in the direction of arrow A, the car 14 is lifted by the main rope 34 portion from the first end portion 34a to the first return pulley 22, and the counterweight 30 descends due to its own weight and the like. On the contrary, when the drive sheave 26 is rotated in the direction of arrow B, the counterweight 30 is lifted by the main rope 34 portion from the second return pulley 28 to the second end portion 34b, and the car 14 descends due to its own weight and the like.

[0032] <Scaffoldless method, mobile working floor> For the installation of the equipment inside the hoistway of the elevator 10, a scaffoldless method is used. Examples of the equipment inside the hoistway include protection wires (vertical protection wires, horizontal protection wires), landing detection plates, various limit switches, etc. (none of which are shown). The protection wires are provided for the purpose of preventing long objects such as ropes and cables from being caught by protrusions inside the hoistway. The landing detection plates are installed for each destination floor and are used to detect the landing position by sensors provided on the car side. The limit switches are provided in plural in the vertical direction near the top floor and the bottom floor, for example, and detect the vertical position of the car 14 when a part of the car 14 abuts. In this case, as the limit switches, four switches, namely, "deceleration switch", "safe distance ensuring switch", "overshooting prevention switch", and "final limit switch (collision prevention)", are provided in order from the middle of the vertical direction of the hoistway 20.

[0033] The above-mentioned equipment inside the hoistway is installed by a worker who gets on the mobile working floor 52. Fig. 2 shows a side view of the mobile working floor 52. The mobile working floor 52 has a cage frame 54 including a rectangular frame body composed of an upper frame 56 extending in the front-rear direction of the drawing, a lower frame 58, and a pair of vertical frames 60 connecting the upper frame 56 and the lower frame 58 (only the front vertical frame 60 appears in Fig. 2).

[0034] At both ends of the lower frame 58, a pair of support members 62 made of steel sections are joined in a posture orthogonal to the lower frame 58 (in Fig. 2, only the front support member 62 appears). The pair of support members 62 support a lower work floor 64 made of a plate body having a square shape in plan view.

[0035] At both ends of the upper frame 56, a pair of support members 66 made of steel sections are joined in a posture orthogonal to the upper frame 56 (in Fig. 2, only the front support member 66 appears. The pair of support members 66 support an upper work floor 68 made of a plate body having a square shape in plan view.

[0036] Further, the movable work floor 52 is provided with three safety fences so as to surround three sides of the upper work floor 68. In Fig. 2, two of these safety fences 70, 72 appear. The third safety fence has the same configuration as the safety fence 70 and is provided at a position facing the safety fence 70.

[0037] Each of the safety fences 70, 72 has upper rails 70a, 72a and middle rails 70b, 72b provided horizontally (in this example, in the horizontal direction). The upper rails 70a and the middle rails 70b both have substantially the same length as one side of the upper work floor 64.

[0038] The movable work floor 52 has a hoist 18 (Fig. 1), but its illustration in Fig. 2 is omitted. Further, although the movable work floor 52 has an emergency stop device and roller guides 80 (Figs. 10, 11, 12) described later that are guided by the cage guide rails 40, 42 (Fig. 1), their illustration in Fig. 2 is omitted.

[0039] From the mobile work floor 52 with the above configuration, members used only in the scaffolding-free method are removed, and side walls and a car door device 17 that form the car cabin are attached, completing the passenger car 14. In other words, the mobile work floor 52 is in a state before attaching side walls, a car door device 17, etc. to the car frame 54, that is, a state where a worker can board and work toward the inner walls of the four hoistways 20 (nothing that obstructs work is attached to the car frame 54), and can move up and down in the hoistway 20. Here, the completed passenger car 24 of the elevator 10 will also be referred to as the "installed passenger car."

[0040] <Moving limit detection switch> As described above, in the scaffolding-free method, a worker who boards the mobile work floor 52 raises and lowers the mobile work floor 52 and performs the work while it is stopped at a desired position. A simple operation button device (not shown) for giving this raising and lowering instruction is provided on the mobile work floor 52. Since communication with the control panel 50 is limited to raising and lowering instructions, etc., the traveling cable connected to the mobile work floor 52 is lighter than that connected to the installed passenger car.

[0041] During the scaffolding-free method, since the above various limit switches are not attached to the wall of the hoistway 20 or, even if attached, are not yet functioning, for example, if a worker is distracted by operating the operation button device and goes beyond the upper limit, a situation where the worker is pinched between the hoistway ceiling and the mobile work floor is assumed. Also, if the lower limit is exceeded, a situation where a worker working in the pit PT between the bottom of the hoistway 20 and the mobile work floor is pinched is assumed.

[0042] Therefore, the movement limit detection switch 100 is used. The movement limit detection switch 100 detects that the moving work floor 52 has approached the ceiling of the hoistway 20 or the bottom of the hoistway 20 (pit bottom), which is an obstacle existing at the movement destination of the moving work floor 52 that moves up and down within the hoistway 20. When the obstacle is the ceiling of the hoistway 20, the movement limit detection switch 100 is used by being attached to the safety fences 70 and 72 of the moving work floor 52. On the other hand, when the obstacle is the pit bottom of the hoistway 20, it is used by being attached to the car guide rails 40 and 42. Each mounting mode will be described later.

[0043] The front view of the movement limit detection switch 100 is shown in Fig. 3(a), the plan view thereof is shown in Fig. 3(b), and the left side view thereof is shown in Fig. 4(a), respectively. Fig. 4(b) is an exploded assembly view of the first clamp 110. Fig. 4(c) is a cross-sectional view taken along line C·C in Fig. 3(a). In addition, in Fig. 4(c), the illustration of the tension coil spring 150, which will be described later, is omitted.

[0044] The movement limit detection switch 100 has a first bracket 102 and a second bracket 104. The first bracket 102 and the second bracket 104 are made of steel plates by press working such as punching and bending. The first bracket 102 and the second bracket 104 are joined to each other by bolts 105 in a state where a part of them is overlapped.

[0045] The movement limit detection switch 100 has a first clamp 110 as a mounting part for the safety fence and a second clamp 120 as a mounting part for the guide rail. The first clamp 110 has a nut 111 joined to the bent part 102a of the first bracket 102 by welding. A through hole (not shown) communicating with the screw hole (not shown) of the nut 111 is opened in the bent part 102a.

[0046] The first clamp 110 also has a fully threaded bolt 112 screwed into a nut 111. A pressing fitting 113 is attached to one end of the fully threaded bolt 112. A locknut 114 is screwed into the portion of the fully threaded bolt 112 on the side opposite to the pressing fitting 113 with the bent portion 102a interposed therebetween.

[0047] The first clamp 110 also has a knob 115 made of synthetic resin. A nut 116 is embedded in the knob 115 (Fig. 4(b)). The assembling method of the first clamp 110 including the above-described components will be described with reference to Fig. 4(b). Hold the pressing fitting 113 and screw the fully threaded bolt 112 into the nut 111 from the side opposite to the bent portion 102a. Screw the locknut 114 into the tip of the fully threaded bolt 112. Then, the state shown in the upper figure of Fig. 4(b) is obtained. After screwing the tip portion of the fully threaded bolt 112 into the nut 116, the locknut 114 is tightened against the knob 115, and the assembly is completed (Fig. 4(a)).

[0048] In the axial direction of the fully threaded bolt 112, in front of the pressing fitting 113, there is a bent portion 104b of the second bracket 104. By sandwiching an object, specifically, the upper crossbar 72a or the upper crossbar 72b, between the pressing fitting 113 and the main surface of the bent portion 104b, the movement limit detection switch 100 is attached to the safety fence 70 or the safety fence 72. The main surface of the bent portion 104b will be referred to as a receiving portion 117. The specific mounting mode to the safety fence 72 will be described later.

[0049] The second clamp 120 basically has the same configuration as the first clamp 110 except for the different mounting positions. Therefore, the components of the second clamp 120 are numbered with a three-digit number starting with 2, and the first digit of the number of the corresponding component in the first clamp 110 is used. The detailed description of the configuration of the second clamp 120 will be omitted.

[0050] The nut 121 of the second clamp 120 is joined to the bent portion 104a of the second bracket 104. In the second clamp 120, the pressing fixture 123 and the side surfaces of the bent portion 104b and the bent portion 104c of the second bracket 104 sandwich an object, specifically, the cage guide rail 40 or 42, so that the movement limit detection switch 100 is attached to the cage guide rail 40 or 42. The side surfaces of the bent portion 104b and the side surfaces of the bent portion 104c will be referred to as receiving portions 127 (FIG. 3(b)). Specific mounting modes to the cage guide rails 40 and 42 will be described later.

[0051] The movement limit detection switch 100 has a linear cam 130. FIG. 5(a) shows a front view of the linear cam 130, FIG. 5(b) shows a plan view thereof, and FIG. 5(c) shows a left side view thereof. Further, a cross-sectional view taken along line A-A in FIG. 5(a) is shown in FIG. 5(d), and a cross-sectional view taken along line B-B is shown in FIG. 5(e). Note that FIGS. 5(d) and 5(e) show only the cut surfaces, and the illustration of the background is omitted.

[0052] The linear cam 130 is made of a steel plate by press working such as punching and bending. The linear cam 130 has a substantially "C" - shaped cross section over its entire length. A long hole 131a is provided in its bottom 131. The side walls 132 and 133 bent at right angles from both sides of the bottom 131 are mostly in the shape of an elongated rectangle, and the upper end portions are formed wider than the rectangular portions. A square steel plate is joined to the upper end of the widened upper end portion, and this steel plate becomes the contact portion 134 described later.

[0053] As shown in FIG. 5(a), the lower end portion of the side wall 132 is bent inward in a "Γ" - shaped manner. The outer surface of the side wall 132 functions as a guide surface for an actuator 163 (roller 162) described later. Here, the guide surface of the "Γ" - shaped bent portion is defined as the guide surface 132a, and the guide surface of the portion bent at right angles from the bottom 131 is defined as the guide surface 132b. The guide surface 132b extends over substantially the entire length of the linear cam 130 except for the guide surface 132a.

[0054] The lower end portion of the side wall 132 is also bent at a right angle in the width direction of the bottom 131 as shown in FIGS. 5(a) and 5(c), forming a spring attachment portion 132c. An attachment hole 132d is provided in the spring attachment portion 132.

[0055] As shown in FIG. 4(c), the linear cam 130 is attached to the second bracket 104 by two bolts 142 and 144. Female threads 104d and 104e are formed in the second bracket 104 at intervals in the vertical direction, and screw insertion holes 102b and 102c communicating with the respective female threads 104d and 104e are provided in the first bracket 102.

[0056] Each of the bolts 142 and 144 is inserted into the long holes 131a of the linear cam 130, the screw insertion holes 102b and 102c, and is screwed into the female threads 104d and 104e, respectively.

[0057] On the screw portions between the heads of the bolts 142 and 144 and the first bracket 102, flat washers 143 and 145, and collars 146 and 148 which are cylindrical members are externally inserted in order from the head side (the screw portions are inserted into the flat washers 143 and 145, and the collars 146 and 148, respectively). The outer diameters of the collars 146 and 148 are slightly shorter than the width of the long hole 131a, and the outer diameters of the flat washers 143 and 145 are set to be sufficiently longer than the width of the long hole 131a.

[0058] With the above configuration, the linear cam 130 is guided by the collars 146 and 148 fitted in the long holes 131a, and is attached to the second bracket 104 so as to be slidable in the vertical direction.

[0059] A third bracket 106 having an "L" shape in a front view (FIG. 3(a)) is attached (fixed) to the second bracket 104 by two bolts 107. The third bracket 106 is provided for spring attachment, and an attachment hole 106a is provided as shown in FIGS. 3(a) and 4(a).

[0060] One hook is hooked on the mounting hole 106a, and the other hook is hooked on the mounting hole 132d. The tension coil spring 150, which is a biasing member, is provided between the third bracket 106 and the linear cam 130. The tension coil spring 150 is provided so that the linear cam 130 is always pulled upward (spring-biased) with respect to the third bracket 106.

[0061] In a state where no vertical load is applied to the linear cam 130, the lower end wall of the long hole 131a abuts on the collar 148, and the linear cam 130 is positioned. When an external force is applied to the contact portion 132 in the direction of arrow D (downward), the linear cam 130 slides downward against the pulling force (biasing force) of the tension coil spring 150. When the external force disappears, the linear cam 130 slides (returns) by the restoring force of the tension coil spring 150 until the lower end wall abuts on the collar 148.

[0062] A limit switch 160 that is turned on when the linear cam 130 slides downward is attached to the first bracket 102. As the limit switch 160, for example, a hinge lever type can be used.

[0063] For the limit switch 160, an actuator 163 including a lever 161 and a roller 162 provided at one end functions as a slave joint with respect to the linear cam 130 that functions as a master joint. When the linear cam 130 slides downward, the roller 162 is guided by the guide surface 132a and rolls, and the lever 161 rotates clockwise about the fulcrum 164, so that the limit switch 160 is turned on. And while the roller 162 is guided by the guide surface 132b, the limit switch 160 maintains the on state. That is, the limit switch 160 is turned on when the actuator 163 abuts on the guide surface 132a of the linear cam 130 that slides downward, and maintains the on state while being guided by the guide surface 132b.

[0064] The limit switch 160 is of the normally closed type. That is, when it is turned on, the contacts open, and when it is turned off, the contacts close. Note that the limit switch 160 is not limited to this, and a normally open type in which the contacts close when it is turned on and the contacts open when it is turned off may also be used.

[0065] The limit switch 160 is electrically connected to the control panel 50 during the scaffolding-free construction method. The control panel 50 is also electrically connected to a simple operation button device 170 for giving an instruction to raise and lower the movable work floor 52 during the scaffolding-free construction method. A block diagram showing the electrical connection relationship between the control panel 50, the limit switch 160, and the operation button device 170 is shown in Fig. 6(a). Fig. 6(a) is an example in which the movement limit detection switch 100 is attached to both the safety fence 70 and the cage guide rail 40, and the limit switches 160 are respectively connected to the control panel 50. Here, the limit switch 160 attached to the safety fence 70 is referred to as the limit switch 160U, and the limit switch 160 attached to the cage guide rail 40 is referred to as the limit switch 160D for distinction.

[0066] Note that the limit switches 160U and 160D are respectively connected in the control panel 50 to the circuits to which the above-mentioned two "overshoot prevention switches" (the top floor overshoot prevention switch and the bottom floor overshoot prevention switch) that function in the installed elevator 10 are connected.

[0067] The operation button device 170 is operated (manually operated) by a worker who has boarded the movable work floor 52. As shown in Fig. 6(b), the operation button device 170 has an up button 172, a down button 174, and a STOP switch 176.

[0068] While the upper button 172 is pressed, the movable work floor 52 rises. While the lower button 174 is pressed, the movable work floor 52 descends. When the STOP switch 176 is pushed in, the upper button 172 and the lower button 174 become ineffective (the operation becomes invalid), and in that state, the STOP switch 176 is locked (remains pushed in). The STOP switch 176 is unlocked by turning it in the direction of the arrow shown in Fig. 6(b) and returns to the position before being pushed in.

[0069] <When the movement limit detection switch is attached to the safety fence> A front view of an example in which the movement limit detection switch 100 is attached to the upper crossbar 70a of the safety fence 70 is shown in Fig. 7(a), and a left side view thereof is shown in Fig. 7(b).

[0070] As shown in Fig. 7(a), the movement limit detection switch 100 is attached to the safety fence 70 (Fig. 2) by sandwiching the upper crossbar 70a between the pressing metal fitting 113 of the first clamp 110 and the receiving portion 117 of the second bracket 104. Also, if the knob 115 is loosened, the movement limit switch 100 can be removed from the safety fence 70. That is, the first clamp 110 functions as an attachment means that can be detachably (attachably and detachably) attached to the safety fence 70. Note that the movement limit detection switch 100 may be attached not only to the safety fence 70 but also to the upper crossbar 72a of the safety fence 72.

[0071] Since the upper crossbars 70a and 72a of the safety fences 70 and 72 are provided over substantially the entire length of three sides out of the four sides of the upper work floor 68, the operator can select directly below the protruding portion (convex portion) at the ceiling portion of the hoistway 20 and attach the movement limit detection switch 100.

[0072] Therefore, according to the movement limit detection switch 100, it is possible to avoid, as much as possible, a situation where the roller 14r abuts against the recess in the ceiling and the convex portion of the ceiling and the basket 1 come close to each other beyond a safe distance, as in the conventional switch described in Patent Document 3 that is fixed to the safety fence in advance.

[0073] When the movable work floor 52 with the movement limit detection switch 100 attached thereto as described above attempts to exceed the upper limit (before exceeding the upper limit), first, as shown in Fig. 8(a), the contact portion 134 contacts the ceiling portion 20C and is pushed by the ceiling portion 20C, causing the linear cam 130 to slide downward relative to the first bracket 102. The roller 162 of the limit switch 160 attached to the first bracket 102 is guided along the guide surface 132a of the sliding linear cam 130, and the actuator 163 including the roller 162 rotates clockwise about the fulcrum 164, turning the limit switch 160U on.

[0074] When the limit switch 160U is turned on, that is, when it is detected that the movable work floor 52 has approached the ceiling of the hoistway 20, the control panel 50 performs rotational stop control of the prime mover 25 and prohibits upward movement of the movable work floor 52 while the on state continues.

[0075] Even when the stop control is started, the movable work floor 52 does not stop immediately and continues to rise slightly due to its inertia (Fig. 8(b)). Therefore, the length of the linear cam 130 (guide surface 132b) is set to a length sufficient for the actuator 163 (roller 162) to continue contacting from the start of the stop control until the movable work floor 52 completely stops.

[0076] Since the control panel 50 recognizes that the limit switch 160U is in the on state, in other words, recognizes that the movable work floor 52 is close to the ceiling of the hoistway 20, while upward movement of the movable work floor 52 is prohibited, downward movement is permitted. That is, even when the limit switch 160U is in the on state, when the lower button 174 is pressed, the control panel 50 controls the rotation of the prime mover 25 to lower the movable work floor 52. As a result, the operator can continue the work without interrupting it.

[0077] The height of the upper rails 70a and 72a from the upper work platform 68 and the dimensions of the travel limit detection switch 100 are set so that the movable work platform 52 stops at a position where the upper work platform 68 is at least 1200 mm away from the protruding portion of the ceiling 20C where the abutment portion 134 abuts. The "1200 mm" is a standard set by law regarding maintenance and inspection work for permanent elevators. This standard is intended to prevent workers from being pinched between the upper work platform 68 and the ceiling 20C and to ensure an evacuation space for workers.

[0078] <When the travel limit detection switch is installed on the car guide rail> FIG. 9(a) shows a front view of an example in which the movement limit detection switch 100 is attached to the car guide rail 40, FIG. 9(b) shows a left side view of the same, and FIG. 9(c) shows a plan view of the same.

[0079] As shown in FIG. 9(c), the travel limit detection switch 100 is attached to the car guide rail 40 (FIG. 1) by clamping the two parallel guide surfaces 40a, 40b of the car guide rail 40 between the press fitting 123 of the second clamp 120 and the receiving portion 127 of the second bracket 104. Furthermore, by loosening the knob 125, the travel limit switch 100 can be removed from the car guide rail. In other words, the second clamp 120 functions as an attachment means that can be detachably attached (removably attached) to the car guide rail 40. Note that the travel limit detection switch 100 is not limited to being attached to the car guide rail 40, and it may also be attached to the other car guide rail 42.

[0080] The vertical mounting position on the car guide rail 42 is a distance that does not interfere with work using the scaffolding-free construction method and ensures the safety of workers in the pit PT (FIG. 1) if there are workers in the pit PT. Since the depth of the pit PT varies from construction site to construction site, the vertical mounting position of the travel limit detection switch 100 according to the embodiment can be set according to the depth of the pit PT at the construction site.

[0081] FIG. 10 is a front view of the mobile work floor 52 in a state where it has descended and is close to the movement limit detection switch 100, and FIG. 11 is a side view thereof. FIG. 12 is a front view of the state where the limit switch 160 is in the ON state.

[0082] The mobile work floor 52 has roller guides 80 provided at the lower part of the car frame 54 (vertical frame 60). The roller guides 80 include three rollers 81, 82, and 83. The rollers 81, 82, and 83 are attached to the vertical frame 60 via the attachment unit 84.

[0083] When the mobile work floor 52 attempts to exceed the limit of descent (before exceeding the limit of descent), first, the contact portion 134 contacts a part of the mobile work floor 52 (in this example, a part of the attachment unit 84), and is pushed by this part, causing the direct-acting cam 130 to slide downward relative to the first bracket 102. The operation of the movement limit detection switch 100 hereafter is the same as when it is attached to the safety fence 70 described above.

[0084] When the control panel 50 recognizes that the limit switch 160D is in the ON state, in other words, when it recognizes that the mobile work floor 52 is close to the bottom of the pit PT of the lifting path 20, the control panel 50 prohibits the downward movement of the mobile work floor 52 but allows the upward movement. That is, even when the limit switch 160D is in the ON state, when the up button 172 is pressed, the control panel 50 controls the rotation of the prime mover 25 to raise the mobile work floor 52. Thus, the operator can continue the work without interrupting the work, which is the same as when the movement limit detection switch 100 is attached to the safety fence 70.

[0085] In the above example, the movement limit detection switch 100 is applied to the mobile work floor 52 using roller guides as a device for guiding the car guides 40 and 42. However, the movement limit detection switch 100 is also applicable to a mobile work floor having a guide shoe instead of a roller guide. In this case, the contact portion 134 of the direct-acting cam 130 of the movement limit switch 100 contacts a part of the guide shoe.

[0086] The outer shapes of the roller guides and guide shoes slightly differ depending on the model. Therefore, the width of the contact portion 134 of the movement limit detection switch 100 attached to the car guides 40 and 42 is made larger than the width of the guide surface 132b necessary for guiding the actuator 163 (roller 162) so that the contact portion 134 surely contacts a part of the roller guide or guide shoe (Fig. 5(c)).

[0087] Since the roller guides and guide shoes are usually provided at the lowest position on the moving work floor, they are suitable elements for depressing the direct-acting cam 130 of the movement limit detection switch 100 to stop the downward movement of the moving work floor. However, the element for depressing the direct-acting cam 130 is not limited to the roller guides and guide shoes, and other components may also be used. The key is to attach the movement limit detection switch 100 to the car guides 40 and 42 so that the moving work floor 52 can be stopped at a position where the safety of the worker working in the pit PT is ensured, and a part of the descending moving work floor can contact the contact portion 134 which is the upper end of the direct-acting cam 130.

[0088] As described above, the movement limit detection switch 100 according to the embodiment can be attached to the safety fences 70 and 72 or to the car guides 40 and 42. That is, one movement limit detection switch 100 is useful for ensuring the safety distance between the moving work floor 52 and the ceiling of the hoistway 20, or for ensuring the safety distance between the moving work floor 52 and the bottom of the pit PT.

[0089] The movement limit detection switch according to the present invention has been described based on the embodiment above, but of course, the present invention is not limited to the above-described form, and for example, the following forms are also possible.

[0090] (1) In the above embodiment, an example of using the movement limit detection switch in the scaffolding-free method of a machine-roomless elevator has been shown, but the movement limit detection switch according to the present invention can also be used in the scaffolding-free method of a rope-type elevator having a machine room above the hoistway.

[0091] (2) In the above-described embodiment, the movement limit detection switch 100 was used to stop the moving work floor 52 approaching the ceiling of the hoistway 20 or the bottom of the pit PT. However, the present invention is not limited to this. For example, it may be used to issue an alarm when the moving work floor 52 approaches the ceiling or the bottom of the pit. This can be realized by connecting an alarm device (not shown) to the control panel 50 and causing the alarm device to emit an alarm sound under the control of the control panel 50 when the movement limit switch 100 is turned on.

[0092] (3) In the above-described embodiment, the movement limit detection switch 100 is configured to include both a mounting portion for a safety fence (first clamp 110) and a mounting portion for a guide rail (second clamp 120) as mounting means. However, only one of them may be used. When the movement limit detection switch is configured to include only the first clamp 110 as the mounting means, it is used for work in the upper part of the hoistway. When the movement limit detection switch is configured to include only the second clamp 120, it is used when there is work by an operator in the pit PT, and so on, and they can be used separately according to the situation.

Industrial Applicability

[0093] The movement limit detection switch according to the present invention can be suitably used, for example, as a switch for detecting the limit of the elevation of a moving work floor in a method of constructing an elevator without a scaffold.

Explanation of Reference Numerals

[0094] 100 Movement limit detection switch 110 First clamp 120 Second clamp

Claims

1. A mechanical movement limit detection switch used in the method of constructing an elevator without a scaffold, which detects that a moving work floor moving up and down in a hoistway approaches an obstacle at the destination, having attachment means that can be detachably attached to a member existing in the hoistway, wherein the moving work floor includes a car frame, an upper work floor provided above the car frame, and a safety fence for ensuring the safety of a worker when working on the upper work floor, the member when the obstacle is the ceiling of the hoistway is the safety fence, the member when the obstacle is the bottom of the pit of the hoistway is a guide rail for guiding the up and down movement of the moving work floor, the attachment means includes both an attachment part for the safety fence that can be detachably attached to the safety fence and an attachment part for the guide rail that can be detachably attached to the guide rail. The movement limit detection switch is characterized by this.

2. including a linear motion cam having a guide surface and sliding in the vertical direction, a biasing member that biases the linear motion cam upward elastically, a limit switch including an actuator, having, when attached to the safety fence by the attachment part for the safety fence and the moving work floor moves upward, the upper end of the linear motion cam abuts against the ceiling, and the linear motion cam slides downward against the biasing force of the biasing member, so that the guide surface abuts against the actuator and the limit switch is turned on, thereby detecting that the moving work floor approaches the ceiling, when attached to the guide rail by the attachment part for the guide rail and the moving work floor moves downward, the upper end of the linear motion cam abuts against a part of the moving work floor, and the linear motion cam slides downward against the biasing force of the biasing member, so that the guide surface abuts against the actuator and the limit switch is turned on, thereby detecting that the moving work floor approaches the bottom of the pit. The movement limit detection switch according to Claim 1 is characterized by this.

3. The movement limit detection switch is electrically connected to a control panel that controls the up and down movement of the moving work floor, The control panel prohibits the upward movement of the movable work floor by controlling the rotation of the prime mover, which is the power source for the lifting and lowering of the movable work floor, to stop while the limit switch of the movement limit detection switch attached to the safety fence is in the on state, and prohibits the downward movement of the movable work floor by controlling the rotation of the prime mover to stop while the limit switch of the movement limit detection switch attached to the guide rail is in the on state. The linear cam has a length sufficient for the guide surface to continue to contact the actuator at least from the start of the stop control until the movable work floor that moves up and down due to its inertia stops. The movement limit detection switch according to claim 2, characterized in that.

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