JPS6219234Y2 - - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a safety device for a lifting platform.

In an elevating platform having a configuration in which the elevating member is biased upward by a gas spring, a drafting machine, etc. is installed on the elevating member, and the elevating member is fixed to the upright leg member side at an arbitrary elevated position by a brake device. In this case, if the gas escapes from the cylinder of the gas spring and the elastic force of the gas spring disappears, the elastic force will not act upwardly on the lifting member, so when the brake on the lifting member is released. The lifting member may fall suddenly due to the weight of the drawing machine, etc., which is extremely dangerous. Therefore, a German patent has developed a safety device that prevents the brake from being released even if the brake release pedal is stepped in the brake release direction when the gas spring is out of gas.
It is shown in specification No. 2549542. This device is
The brake mechanism is designed to increase the pressing force of the brake shoe against the lifting member when gas from the gas spring is released and a large weight is applied to the lifting member, and the brake of the brake release pedal increases when the pressing force of the brake shoe against the lifting member exceeds a predetermined value. A transmission force escape mechanism is provided that prevents the release motion from being transmitted to the brake mechanism due to the displacement of the spring. In the above device, if the spring of the transmission force relief mechanism deteriorates over time and its elastic force weakens, even if the gas spring is normal, the displacement of the brake operation pedal in the brake release direction will not be transmitted to the brake mechanism, and the elevating member will It becomes impossible to release the brake. Therefore, when the brake on the lifting member cannot be released, the user of the lifting platform must check whether the spring of the transmission force relief mechanism is normal and whether there is any gas leakage from the gas spring. Must be. These tests are time-consuming and have the disadvantage of requiring a specialist to be used.

The object of the present invention is to provide a safety device for a lifting platform that eliminates the above-mentioned defects.

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 lifting member having a square cross section, and 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 and 12 and the frame plate 1.
It consists of four pillars 14 connecting the four corners of the frame 8, and the central space of the frame 8 is loosely fitted into the elevating member 6. The frame body 8 has mounting pieces 16 and 18.
are formed, and the mounting pieces 16, 18 are fixed to the leg member 4 with screws. Frame plate 1 of the frame body 8
A roller 20 is rotatably attached to each of the four sides of the lift member 6. 4 is supported so as to be movable up and down along the longitudinal direction. A guide piece 22 is provided protrudingly on the inner wall surface of the elevating member 6.
A cylinder 26 of a commercially available gas spring 24 is placed in the hollow portion of the elevating member 6 with its position regulated. 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. Mounting blocks 28 and 30 are fixed to the upper end of the elevating member 6 by bolts 32 and 34. 36 is a horizontal pipe, and the block 2
It is held at 8.30. A drawing board support frame 38 is attached to both ends of the horizontal pipe 36. A hole is formed in the block 28, into which a cap 40 having a tab is screwed. The upper end of the cylinder 26 of the gas spring 24 is in contact with the lower surface of the cap 40. 42 is a cover. A drawing board is attached to the drawing board support frame 38,
A drawing machine is installed on the drawing board. 4
Reference numeral 4 designates a pair of levers (the other is not shown) that are connected to each other, and the center part of these levers is connected to the upper plate part 2 of the base 2.
It is rotatably supported by a shaft 46 on a bracket fixed to a. A brake release pedal 48 is provided at each end of the lever 44 .

Next, the leg member 4 is moved to an arbitrary elevating position by the elevating member 6.
The brake mechanism for fixing the vehicle will be explained below. Reference numeral 50 designates a pair of brake arms, and the vicinity of both ends thereof are connected to the shaft rod 5 as shown in FIG.
2,54 are being constructed. The shaft rods 52, 54
Brake rods 56, 58 are rotatably attached to the. Brake shoes 60 and 62 are bonded to the brake rods 56 and 58, and the brake shoes 60 and 62 face the wall surface of the elevating member 6. Reference numerals 64 and 66 indicate leaf springs fixed to substantially central portions of the brake rods 56 and 58, respectively. When the brakes are released, the protrusions formed at both ends of each leaf spring come into light elastic contact with the wall surface of the elevating member 6. The brake shoes 60 and 62 are moved up and down by the lifting member 6 by elastic contact force.
It is held parallel to the wall surface. 68,7
0 is a plate member fixed to two pillars 14,
A long groove 72 is formed in each of these, and a pin 74 protruding from each one of the pair of arms 50 is slidably fitted into the long groove 72. An L-shaped mounting piece 76 is fixed to the other end of one arm 50, and the upper end of a rod 78 is rotatably connected to the mounting piece 76. The lower part of the rod 78 is loosely fitted into a hole in a guide piece 80 fixed to the leg member 4 so as to be movable up and down. Reference numeral 82 denotes a coil spring, the lower end hook of which is hung on a hook formed on the frame plate 12, and the upper end hook of the coil spring 82 connected to the mounting piece 76.

Next, the transmission force relief mechanism will be explained.

Reference numeral 84 denotes a U-shaped connecting member, and a pair of shaft bodies 86, 88 are connected to this at an appropriate interval in a substantially horizontal direction.
The shafts 86 and 88 are rotatably fitted into holes formed in the rods 78 and 90. The rod 90 is loosely fitted into a hole in a guide piece 92 fixed to the leg member 4 so as to be able to move up and down.
Nuts 94, 96 are attached to the threaded part formed at the bottom of the
are screwed together. The nut 96 is in contact with the upper surface of a flat plate mounted on the other end of the pair of levers 44 through a hole formed in the upper plate portion 2a of the base 2. Reference numeral 98 denotes an arm member fixed to the connecting member 84, and a long hole 100 is formed through the arm member 98.
A scale is engraved along the elongated hole 100.
Reference numeral 102 denotes a weight, and a screw hole is bored in the protrusion at the center of the weight. 104 is a bolt slidably arranged in the elongated hole 100, and the arm member 9
The arm member 98 is screwed into a threaded hole in the weight 102 on the other side of the arm member 98 via a washer from one side of the arm member 8 . The stopper shaft 106, which is attached to the connecting member 84, is brought into contact with the rod 78 by a moment in the rotational direction of the hour hand in FIG. 2 about the shaft 86 of the connecting member 84 due to the weight of the weight 102.

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 lifting member 6 including the drawing machine and the like. As a result, the upward force of the gas spring 24 against the lifting member 6 and the lifting force of the lifting member 6
The falling forces are balanced, and the lifting member 6 can be easily raised and lowered with a small manual operation force in the brake released state. Coil spring 82 is connected to arm 5
0 is pulled downward, and this pulling force causes the arm 50 to tilt in the counterclockwise direction of rotation of the hour hand in FIG.
is pressed against the wall surface of the elevating member 6, and the elevating member 6 is normally fixed to the leg member 4. Note that since one end of the arm 50 is pulled downward by the weight of the weight 102, the coil spring 82 may not be provided. When the brake release pedal 48 is depressed with the foot, the lever 44 moves to the second position about the shaft 46.
In the figure, the hour hand swings in the direction of rotation, and the rod 90 rises. The weight of the weight 98 causes the connection member 84 to
Since rotation in the counter-rotational direction of the hour hand in FIG. 2 about the shaft 86 is prevented, the connecting member 84 moves upward in parallel in conjunction with the rise of the rod 90.
The rod 78 connected to the connecting member 84 is raised.
As the rod 78 rises, the arm 50 moves to the pin 74.
As shown in FIG. 2, the brake shoes 60 and 62 swing horizontally in the rotational direction of the hour hand as shown in FIG.
The brake of the elevating member 6 is released as the elevating member 6 moves away from the wall surface. At this time, the protrusions of the leaf springs 64 and 66 lightly come into elastic contact with the wall surface of the elevating member 6, and the brake shoe 6
0 and 62 are regulated parallel to the wall surface of the elevating member 6. When the lifting member 6 is braked, the cylinder 26 of the gas spring 24
When the gas escapes, the balance between the lifting force and the descending force of the lifting member 6 is lost, and the lifting member 6 tends to fall suddenly due to the total weight applied thereto. When the elevating member 6 is about to fall suddenly, a force that pushes the brake shoe 60 downward acts on the brake shoe 60 that is pressed against the elevating member 6, and this pushing force causes the arm 50 to move around the pin 74 as shown in FIG. , since the hour hand moves in the counterclockwise direction, the brake shoe 6
0 and 62 sink into the wall surface of the elevating member 6 and are strongly pressed. The pressing force of the brake shoes 60 and 62 against the wall surface of the lifting member 6 is larger than the pressing force due to the spring force of the coil spring 82.
is firmly fixed to the leg member 4 with a greater braking force than the normal braking force due to gas release from the gas spring 24. In this state, step on the pedal 48, swing the lever 44 about the shaft 46 in the direction of rotation of the hour hand in FIG.
When the weight 98 is raised, a large load is applied to the rod 78 due to the increase in the braking force of the brake mechanism, so the connecting member 84 moves around the shaft 86 as shown in FIG. 2 against the weight of the weight 98. The hour hand swings in the counterclockwise rotational direction, and the upward movement of the rod 90 is not transmitted to the rod 78. That is, even if the pedal 48 is stepped on, the brake cannot be released. In this case,
Gas spring 24 must be replaced.
To do so, first lift the elevating member 6 manually,
The brake shoes 60 and 62 are released from their press-fit state by being bitten into the wall surface of the elevating member 6, and in this state, the pedal 48 is stepped on to release the brake, and the elevating member 6 is gently lowered to the lowest position. Next, remove the cover 42 and cap 40, pull the gas spring 24 upward from the upper end of the lifting member 6 to remove it, and insert a new gas spring into the lifting member 6 from the upper end with its piston rod facing down. . Next, lift the elevating member 6 by hand so that the height of the upper end of the elevating member 6 approximately matches the height of the upper end of the gas spring, and in this state, the cap 4
0 into the screw hole of the block 28 and release the lifting member 6, the lower surface of the cap 40 comes into elastic contact with the upper end of the cylinder of the gas spring. To adjust the rotational moment in the direction of rotation of the hour hand in FIG.
This can be done by moving the position of the weight 102 along 0. In addition, when carrying out the present invention, when the falling force of the elevating member 6 is applied to the brake shoe 60, the elevating member 6 of the brake shoe 60, 62
In addition to the configuration shown in the drawings, various configurations such as the one shown in Japanese Utility Model Application Publication No. 56-125738 can be adopted for the brake mechanism designed to increase the pressing force against the brake member. As mentioned above, this invention uses a weight in the transmission force relief mechanism to prevent the brake release displacement of the brake release pedal from being transmitted to the brake mechanism when the gas spring is degassed, so that the spring wears out due to aging. can solve the problem. Therefore, if the brake cannot be released even if you step on the brake release pedal in the brake release direction, there is no other cause than gas leakage from the gas spring, so there is no need to inspect the spring and gas spring as in the past. Since it is only necessary to replace the gas spring, there is an advantage that repair work of the device can be carried out extremely easily.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the present invention, in which Fig. 1 is an overall external view, Fig. 2 is a vertical sectional view, Fig. 3 is a cross-sectional view taken along the line A-A, and Fig. 4 is a cross-sectional view taken along the line B-B. FIG. 5 is a partial longitudinal sectional view. 2... Base, 4... Leg member, 6... Lifting member, 24...
Gas spring, 26...Cylinder, 36...Horizontal pipe, 38...Drawing board support frame, 44...Lever, 48...
Brake release pedal, 50...Brake arm, 6
0, 62... Brake shoe, 72... Long groove, 74... Pin, 78... Rod, 82... Coil spring, 84... Connecting member, 90... Rod, 98... Arm member, 102...
weight.

Claims (1)

[Scope of utility model registration request] The lifting members include the leg member 4, the lifting member 6 supported by the leg member 4 so as to be able to move up and down, the gas spring 24 for applying elastic force upward to the lifting member 6, and the brake shoes 60 and 62. 6 to fix the elevating member 6 to the leg member 4 side, and when the downward moving force of the elevating member 6 is transmitted to the brake shoe 60, the pressing force of the brake shoe 60 against the elevating member 6 increases. and a brake release pedal 4 for separating the brake shoe 60 of the brake mechanism from the elevating member 6.
8, the brake shoe 6
A first rod 78 connected to the brake release pedal 48 and a second rod 90 connected to the brake release pedal 48 are rotatably supported by shafts 86 and 88 at a predetermined interval on the connection member 84, respectively. 2 rod 90
The connecting member 8 is moved in the brake release direction.
The connecting member 84 rotates in a direction opposite to the rotational movement about the shaft support 86 with the first rod 78 of 4.
Weight 1 to generate a rotational moment in
02 is attached to the connecting member 84.