JPS6228915Y2 - - Google Patents

Description

[Detailed description of the invention] This invention uses the elastic force of a gas spring to urge the leg member on the lifting side in the upward direction, and at the same time, the leg member on the lifting side is restrained by the fixed leg member at an arbitrary raised position. When the elastic force of the gas spring disappears on a lifting platform equipped with a brake mechanism for lifting, the brake mechanism cannot be released even if the operating pedal of the brake mechanism is driven in the brake release direction. This invention relates to a safety device that prevents a member from falling suddenly due to the weight of the member.

The configuration of the present invention will be described in detail below based on embodiments shown in the accompanying drawings.

Reference numeral 2 denotes a base, on which hollow leg members 4 are erected. Reference numeral 6 denotes a hollow leg member having a rectangular cross section, which is loosely fitted into the hollow portion of the leg member 4. 8 is a frame body, which includes a pair of frame plates 10, 12 and the frame plate 10,
The frame body 8 is composed of four pillars 14 connecting the four corners of the frame body 8, and the central space of the frame body 8 is loosely fitted into the leg member 6. Attachment pieces 16, 18 are formed on the frame 8, and the attachment pieces 16, 18 are fixed to the leg member 4 with screws. a frame plate 10 of the frame body 8;
A roller 20 is rotatably attached to each of the four sides of the leg member 12, and the surface of the roller abuts against the four sides of the leg member 6 with appropriate pressure, and the roller 20 causes the leg member 6 to press against the leg member 4. It is supported so that it can be raised and lowered along the longitudinal direction. A guide piece 22 is protruded from the inner wall surface of the leg member 6, and a cylinder 26 of a commercially available gas spring 24 is placed in the hollow portion of the leg member 6, the position of which is regulated by the guide piece 22. The lower end of the piston rod of the gas spring 24 is placed on the upper surface of the upper plate portion 2a of the base 2. Reference numeral 28 denotes a mounting block that is detachably attached to the open upper end of the leg member 6. The upper end of the cylinder 26 of the gas spring 24 comes into elastic contact with the lower surface of the block 28, and the elastic force of the gas spring 24 causes the mounting block to be detachably attached. Therefore, the leg member 6 is biased in the upward direction. A horizontal pipe 30 is supported on the mounting block 28, and a drawing board support frame 32 is attached to the horizontal pipe 30. A drawing board is attached to the drawing board support frame 32,
A drawing machine is installed on the drawing board.

A pair of levers 34 (the other is not shown) are connected to each other, and one end of the levers is rotatably connected to a shaft 36 on a bracket fixed to the upper plate 2a of the base 2.
supported. A brake release pedal 38 is provided at one end of each lever 34 .

Next, a brake mechanism for fixing the leg member 6 to the leg member 4 at any vertical position will be explained.

Reference numeral 40 designates a pair of brake arms, and near both ends of these arms are shaft rods 42, 40, as shown in FIG.
44 have been constructed. Brake rods 46 and 48 are rotatably attached to the shaft rods 42 and 44, respectively. Brake shoes 50 and 52 are bonded to the brake rods 46 and 48, and the brake shoes 5
0 and 52 face the wall surface of the leg member 6. 5
Reference numerals 4 and 56 indicate leaf springs fixed to substantially central portions of the brake rods 56 and 58, respectively, and when the brakes are released, protrusions formed at both ends of each leaf spring come into light elastic contact with the wall surface of the leg member 6. The brake shoes 50, 52 are held parallel to the wall surface of the leg member 6 by the elastic contact force. Reference numerals 58 and 60 indicate plate members fixed to the two pillars 14, each of which has a long groove 62 formed at right angles to the longitudinal direction of the leg member 4, and a pair of brake arms in the long groove 62. A pin 64 protruding from each side of 40 is slidably fitted. A coil spring 66 is suspended between the frame plate 12 and one end of the brake arm 40, and biases the arm 40 about the pin 64 in the counterclockwise direction of rotation of the hour hand in FIG.

Next, the brake release transmission force relief mechanism will be explained.

68 is a flexible tube when not compressed, one end of which is fixed to a wire guide 70 that is located above one end of the brake arm 40 and fixed to the support column 14, and the other end of the tube 68 is fixed to a wire guide 70 that is fixed to the support column 14. The guide piece 72 is loosely fitted into a hole in a guide piece 72 fixedly provided below the guide piece 4. A wire 74 is disposed within the tube 68, and one end of the wire 74 is guided by a wire guide 70 and inserted into the arm 40 from above the arm 40.
0, and the other end of the wire 74 is guided by a wire guide 76 and fixed to the vertically movable portion of the lever 34 via a metal fitting from above the lever 34. Reference numeral 78 is a tubular body fixed to a hole in the upper plate portion 2a of the base 2, and a tubular wire guide 76 is screwed into the inner peripheral portion of this tubular body. Reference numeral 78 denotes a tubular body tightly fitted to the free end of the tube 68, and a coil spring 80 is compressed and disposed between the flange of the tubular body 78 and the flange of the wire guide 76.
The elastic force of the coil spring 80 against the tubular body 78 is set to be stronger than the tensile force of the coil spring 66.

Next, the operation of this embodiment will be explained.

The model of the gas spring 24 is selected so that the magnitude of the elastic force of the gas spring 24 is approximately the same with respect to the total weight of the leg member 6 including the drawing machine and the like. As a result, the upward force of the gas spring 24 on the leg member 6 and the falling force of the leg member 6 are balanced, and the leg member 6 can be easily raised and lowered with a small manual operating force in the brake released state. The coil spring 66 pulls one end of the arm 40 downward, and this tensile force causes the arm 4 to
0 is tilted in the counterclockwise rotational direction in FIG. 2 about the pin 64, and the brake shoes 50 and 52 are pressed against the wall surface of the leg member 6, and the leg member 6 is normally fixed to the leg member 4. When the brake release pedal 38 is depressed by foot, the wire 74 moves within the tube 68, and the wire 74 is connected to one end 40a of the arm 40.
pull upwards. As a result, the arm 40 swings about the pin 64 in the direction of rotation of the hour hand in FIG. The brake is released.

If the gas escapes from the cylinder 26 of the gas spring 24 while the brake is applied to the leg member 6, the balance between the lifting force and the descending force of the leg member 6 will be lost, and the leg member 6 will lose its strength due to the total weight applied thereto. Trying to fall suddenly. When the leg member 6 is about to fall suddenly, a force that pushes the brake shoe 50 downward acts on the brake shoe 50 that is pressed against the leg member 6, and this pushing force causes the arm 40 to move around the pin 64 as shown in FIG. Since the brake shoes 50 and 52 move in the upward and counterclockwise rotational directions, the brake shoes 50 and 52 sink into the wall surface of the leg member 6 and are strongly pressed. Since the pressing force of the brake shoes 50, 52 against the wall surface of the leg member 6 is greater than the pressing force due to the spring force of the coil spring 66, the leg member 6 has a lower than normal braking force due to the gas leakage of the gas spring 24. is firmly fixed to the leg member 4 with a large braking force. In this state, when the pedal 38 is stepped on and the lever 34 is swung about the shaft 36 in the direction of rotation of the hour hand in FIG. 4
The one end 40a of the tube 68 does not rise due to the upward pulling force of the wire 74, and the lower end of the tube 68 moves down against the elasticity of the coil spring 80. That is, wire 7
4 is not transmitted to one end 40a of the arm, and even if the pedal 38 is stepped on, the brake cannot be released. If the brake is released at this time, the leg member 6 will fall suddenly due to the weight applied thereto. By rotating the wire guide 76, the elasticity of the coil spring 80 can be adjusted.

Next, another embodiment of the brake release transmission force relief mechanism will be described with reference to FIG. 4.

Reference numeral 90 denotes a tubular wire guide fixed in a hole in the upper plate portion 2a of the base 2. A pipe 92 is slidably inserted into the inner periphery of the wire guide, and the inner periphery of the upper end of the pipe 92 and the tube 68 are connected to each other. A tube body 9 is provided on the inner peripheral surface of the lower end.
4 are tightly fitted, and the flange of the tube body 94 and the wire guide 9
A coil spring 96 is compressed and disposed between the flange portion 0 and the flange portion. In the above configuration, the tube 68
When a downward force exceeding a predetermined value is applied to the lower end of the tube 68, the coil spring 96 is compressed and deformed, and the tube 68 is lowered.

Next, another embodiment of the brake release transmission force escape mechanism will be described with reference to FIG.

Reference numeral 100 designates a tubular body fixed in a hole in the upper plate portion 2a of the base, and a tubular wire guide 1 is attached to the outer periphery of the tubular body.
02 are screwed together. 104 is the wire guide 10
A guide pipe is slidably inserted into the inner circumferential surface of the tube 68, and a tube body 106 is tightly fitted into the inner circumferential surface of the upper end of the guide pipe and the inner circumferential surface of the lower end of the tube 68.
A coil spring 108 is compressed and placed between the flange of the wire guide 102 and the flange of the wire guide 102 .

In the above configuration, when the downward force of the lower end of the tube 68 exceeds a predetermined value due to the tensile force of the wire 74, the coil spring 108 is compressed and deformed.
The lower end of the tube 68 is lowered and the guide pipe 104
descends along the inner peripheral surface of the wire guide 102. By rotating the wire guide 102, the strength of the elastic force of the coil spring 108 can be adjusted.

Next, another embodiment of the brake release transmission force escape mechanism will be described with reference to FIG. 6.

Reference numeral 110 designates an external tubular body that is screwed into a screw hole formed in the upper plate portion 2a of the base, and the outer circumferential portion of a tubular wire guide 112 is screwed into the internal threaded portion of this external tubular body. Reference numeral 114 denotes a tubular body that rotatably fits into the small diameter portion of the upper end of the wire guide 112;
The tube body 11 that fits into the flange of the tube 68 and the lower end of the tube 68
A coil spring 118 is compressed and arranged between the flange portion 6 and the flange portion 6 . 120 is Natsu. The other configurations are the same as the embodiment shown in FIG.

In the above configuration, when the wire guide 112 is rotated relative to the tube body 110, the wire guide 11
2 moves up and down, thereby making it possible to adjust the strength of the elasticity of the coil spring 118.

Since the present invention is configured as described above, it is possible to accurately prevent the brake of the lifting side leg member from being released when the gas in the gas spring is released with a simple configuration. This has the effect of preventing accidents caused by sudden falls.

[Brief explanation of the drawing]

The figures show a preferred embodiment of the present invention, in which Fig. 1 is an external view of the lifting platform, Fig. 2 is a vertical sectional view, and Fig. 3 is an A-
A sectional view taken along line A; FIG. 4 is a sectional view showing another embodiment;
FIG. 5 is a sectional view showing another embodiment, and FIG. 6 is a sectional view showing another embodiment. 2... Base, 2a... Upper plate part, 4... Leg member,
6... Leg member, 24... Gas spring, 34...
... Lever, 38 ... Petal, 40 ... Brake arm, 50, 52 ... Brake shoe, 62 ... Long groove, 64 ... Pin, 66 ... Coil spring,
68...Tube, 70...Wire guide, 74
... wire, 76 ... wire guide, 80 ... coil spring, 90 ... wire guide, 102
... wire guide, 108 ... coil spring, 112 ... wire guide, 118 ... coil spring.

Claims (1)

[Scope of utility model registration request] Another leg member 6 is supported on the leg member 4 so as to be movable up and down,
The elastic force of the gas spring 24 is applied upward to the leg member 6 on the elevating side, and the brake arm 40 is rotatably supported by one of the leg members 4 and 6. 40 in one direction, brake shoes 50, 52 are attached to both ends of the brake arm 40, and the brake shoes 50, 52 are attached to the brake arm 40.
A lever 34 is attached to the lower part of the leg member 4 on the one side so as to be pressed against the wall surface of the other leg member 6 of the leg members 4 and 6 by rotational force in one direction.
is rotatably supported on a shaft 36, one end of a wire 74 is connected to the brake arm 40, and the wire 7
4 is connected to the lever 34, the wire 74 is arranged in a curved manner between the lever 34 and the brake arm 40, and a non-compressible flexible tube 68 is fitted on the wire 74, One end of the tube 68 is separated from the connection part of the wire 74 to the brake arm 40 by a predetermined distance and fixed to the one leg member 4, and the other end of the tube 68 is connected to the lever 34 of the wire 74. The wire 74 is configured to face the tube 68 at a predetermined distance from the brake arm 40 so that the displacement of the wire 74 with respect to the tube 68 due to movement of the lever 34 in a predetermined direction acts on the brake arm 40 in the brake release direction. In order to regulate the position near both ends of the tube 68, wire guides 70, 76 are disposed near both ends of the wire 74 on the leg member 4. A safety device for a lifting platform, characterized in that a coil spring 80 is compressed and arranged between the wire guide 76 and the opposite wire guide 76.