JPS62502Y2 - - 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
As shown in FIG. 1, there is provided a brake mechanism in which the pressing force of the brake shoes 4, 6 against the lifting member 2 increases when the gas in the gas spring 1 is released and a large weight is applied to the lifting member 2;
A transmission force escape mechanism 12 is provided which prevents the brake release motion of the brake release pedal 8 from being transmitted to the brake mechanism by the displacement of the spring 10 when the pressing force of the brake release pedal 6 against the elevating member 2 exceeds a predetermined value. In the above device, when the spring 10 of the transmission force relief mechanism deteriorates over time and its elastic force weakens, even if the gas spring 1 is normal, when the brake release pedal 8 is lowered in the brake release direction b, the initial At this stage, as shown in FIG. 2, the spring 10 is compressed and only the first rod 14 rises relative to the second rod 16, and the movement of the brake release pedal 8 in the brake release direction causes the second rod 16 to move upward. The brake release movement of the second rod 16 is delayed. That is, after the first rod 14 has freely moved by a distance a as shown in FIG. 2, the upward movement of the first rod 14 is transmitted to the second rod 16. Since the lowest position of the brake release pedal 8 is fixed, in order to adjust the above delay,
It may be necessary to rotate the nut 18 to increase the length of the first rod 14. If this adjustment is not made,
If the distance a increases, it becomes impossible to release the brake. However, when the nut 18 is rotated to lengthen the length of the first rod 14, that is, the distance between the connecting portion 22 of the first rod 14 to the foot lever 20 and the nut 18, the elasticity of the spring 10 becomes even weaker. Therefore, there was a problem in that the play a of the second rod when the brake was released further increased.

This device generally retains its magnetic force by 97% even with aging.
The purpose of this is to eliminate the above-mentioned defects by using a permanent magnet whose performance is stable without any deterioration.

Another object of the present invention is to make it possible to easily adjust the relief pressure of a transmission force relief mechanism using a permanent magnet.

The configuration of the present invention will be explained below with reference to the accompanying drawings.

Reference numeral 30 denotes a base, on which hollow leg members 32 are erected. Reference numeral 34 denotes a hollow elevating member having a rectangular cross section, and is supported in the hollow portion of the leg member 32 via a known roller guide device so as to be able to rise and fall freely. 3
6 is a gas spring whose cylinder 36
The upper end of a touches the bottom surface of the upper plate part of the elevating member 34, and the piston rod 36 of the gas spring 36
The lower end of b is placed on the bottom surface of the recessed part of the base 30. 38 is a horizontal pipe supported at the upper end of the elevating member 34, and a drawing board support frame 40 is attached to both ends of this pipe. A drawing board (not shown) is attached to the drawing board support frame 40, and a drawing machine is installed on the drawing board. 42 is a pair of foot levers (the other is not shown) that are connected to each other;
The leg member 32 is rotatably supported on a shaft 44 by a bracket (not shown) fixed to the lower part of the leg member 32. A brake release pedal 46 is provided at one end of each of the pair of levers 42 .

Next, move the elevating member 34 to the leg member 3 at an arbitrary elevating position.
The brake mechanism for fixing to 2 will be explained.

Reference numeral 50 designates a pair of brake arms (the other is not shown), and the vicinity of both ends of these arms are connected to the shaft rod 5.
2,54 are being constructed. The shaft rods 52, 54
Brake rods 56, 58 are rotatably attached to the. Brake levers 60 and 62 are bonded to the brake levers 56 and 58, and the brake levers 60 and 62 are bonded to each other.
0 and 62 face the wall surface of the elevating member 34. Reference numerals 64 and 66 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 elevating member 34. The brake shoes 60 and 62 are moved up and down by the elastic force of the lifting member 3.
It is held parallel to the wall of 4. Reference numeral 68 denotes a pair of plate members (the other is not shown), which protrude from the inner wall surface of the leg member 32. Long grooves are formed in each of the plate members 68, and the pair of arms 50 are inserted into the long grooves. A pin 74 protruding from each side is slidably fitted. A mounting piece 73 is fixed to the other end of one arm 50, and a rod 7 is attached to the mounting piece 76.
The upper ends of 8 are rotatably connected. Rod 78
A weight 80 is fixedly attached to the lower part of.

Next, the transmission force relief mechanism will be explained.

Reference numeral 90 denotes a suction plate made of a magnetic material, and the upper end of the rod 104 is fixed approximately at the center of the suction plate 90, and a hole 94 is formed through one side of the suction plate 90. The lower part of the rod 78 is slidably inserted into the hole 94. Reference numeral 96 designates a plate member, one of which is fixed to the lower end of the rod 78, and a commercially available magnet holder 100, in which a plate-shaped permanent magnet 98 is attached with vertical play, is fixed to the other. There is. The suction plate 90 is attracted to the permanent magnet 98 by magnetic force. A tube body 102 is fixedly installed approximately in the center of the plate member 96 and communicates with a hole formed through the plate member 96.
4 is slidably inserted, and the upper end of the rod 104 is fixed to approximately the center of the suction plate 90.
Reference numeral 106 denotes a bracket fixed to the leg member 32, into which the rod 104 is slidably inserted, and a coil spring 108 is suspended between the bracket 106 and one end of the suction plate 90. The suction plate 90 is urged downward by the tensile force of the coil spring 108. rod 10
A screw is formed at the bottom of 4, and a height adjustment nut is screwed into the screw. The lower end of the nut is in elastic contact with the upper surface of a plate member 110 installed between the tips of the pair of levers 42. The leg member 32
The upper and lower ends of the hole 112 formed in the hole 112 form stoppers that restrict vertical movement of the petal 46. Reference numeral 115 designates a magnetic force adjusting plate made of a non-magnetic material that is slidably fitted to the adsorption plate 90 along the longitudinal direction of the permanent magnet 98, and a holding plate 1 is attached to the upper surface of the magnetic force adjusting plate 115.
16 is placed thereon, and a bolt 117 that is inserted into a hole formed through the holding plate 116 is screwed into a screw hole formed through the suction plate 90.

Next, the operation of this embodiment will be explained.

The model of the gas spring 36 is selected so that the magnitude of the elastic force of the gas spring 36 is approximately the same with respect to the total weight of the lifting member 34 including the drawing machine and the like. As a result, the upward force of the gas spring 36 on the lifting member 34 and the falling force of the lifting member 34 are balanced, and the lifting member 34 can be easily raised and lowered with a small manual operating force in the brake released state. The weight 80 and the coil spring 108 pull one end of the arm 50 downward, and this tensile force causes the arm 50 to tilt about the pin 74 in the counterclockwise direction of rotation of the hour hand in FIG. The elevating member 34 is normally fixed to the leg member 32. When the brake release pedal 46 is depressed with the foot, the lever 42 swings about the shaft 44 in the direction of rotation of the hour hand in FIG.
rises. In conjunction with the rise of the rod 104, the plate member 96 connected to the rod 104 moves upward due to the magnetic attraction force between the adsorption plate 90 and the permanent magnet 98, and the rod 78 connected to the plate member 96 moves upward. The arm 50 is moved to the pin 74 by the rise of the pin 78.
As shown in FIG. 3, the brake shoes 60 and 62 swing horizontally in the rotational direction of the hour hand as shown in FIG.
4 and the brake of the elevating member 34 is released. 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 34, thereby regulating the brake shoes 60 and 62 parallel to the wall surface of the elevating member 34. When the gas is released from the cylinder 36a of the gas spring 36 while the lifting member 34 is braked, the lifting member 34
The balance between the rising force and the descending force is lost, and the lifting member 34 tends to fall suddenly due to the total weight applied thereto. When the elevating member 34 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 34, and this pushing force causes the arm 50 to move around the pin 74 as shown in FIG. , the brake shoes 60 and 62 move in the counterclockwise direction of rotation of the hour hand.
Press firmly into the wall. The pressing force of the brake shoes 60 and 62 against the wall surface of the lifting member 34 is greater than the pressing force due to the spring force of the coil spring 108 and the weight of the weight 80. It is firmly fixed to the leg member 32 with a greater braking force than normal braking force. In this state, step on the pedal 46 and swing the lever 42 about the shaft 44 in the direction of rotation of the hour hand in FIG.
When the rod 104 is raised, the adsorption plate 90 resists the magnetic force of the permanent magnet 98 and separates from the permanent magnet 98 because a large load is applied to the rod 78 due to the increase in the braking force of the brake mechanism described above. , the rise of rod 104 is not transmitted to rod 78, as shown in FIG. That is, even if the pedal 46 is stepped on, the brake cannot be released. The permanent magnet 98 is selected to have the magnetic force necessary to obtain the above effect.

To adjust the attraction force of the permanent magnet 98 to the attraction plate 90, loosen the bolt 117 and move the adjustment plate 115 along the attraction plate 90. This changes the gap between the permanent magnet 98 and the attraction plate 90. In FIG. 6, the attraction force acting between the magnet 98 and the attraction plate 90 increases in the order of a, b, and c. Once the adjusting plate 115 is set at an appropriate position, the bolt 117 is rotated in the tightening direction to fix the adjusting plate 115 to the suction plate 90.

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

78' is a rod corresponding to the above rod 78, and a rod 104' corresponding to the above rod 104.
It is slidably inserted into a tube portion 104'a fixedly attached to the tube portion 104'a. A mounting plate 120 is fixed perpendicularly to the lower end of the rod 78', and the mounting plate 120 is slidably fitted into a vertical groove formed through the tube portion 104'a. A permanent magnet 98 is attached to the mounting plate 120.
A magnet holder 100 holding a is fixed. Reference numeral 122 denotes a tube body fixed to the outer circumferential surface of the tube portion 104'a with a fixing screw, and a suction plate 90 made of a magnetic material is fixed to this tube body.
is attracted to the permanent magnet 98 by magnetic force. 115' is a magnetic force adjusting plate, 116' is a holding plate, 1
Reference numeral 17' indicates a bolt, and these magnetic force adjustment mechanisms have the same structure as in the first embodiment. In a normal brake release operation, the adsorption state between the adsorption plate 90 and the permanent magnet 98 is maintained, and when the gas in the gas spring is released and the braking force of the brake mechanism increases, the rising force of the rod 104' The magnetic force of the permanent magnet 98 is set so that the attraction plate 90 separates from the permanent magnet 98.

In the above configuration, when the gas spring is in a normal state, the upward movement of the rod 104' is transmitted to the rod 78', and the brake of the brake mechanism is controlled to be released. When the gas in the gas spring is released and the pressure applied to the lift member of the brake shoe increases, step on the pedal to raise the rod 104', and the pressure between the adsorption plate 90 and the permanent magnet 98 due to the magnetic force is released. Only rod 104' is raised, and the upward movement of rod 104 is not transmitted to rod 78'. That is, even if the pedal is stepped on, the brake on the elevating member cannot be released, thereby preventing the elevating member from falling suddenly due to release of the brake.

In addition, when implementing the present invention, when the falling force of the lifting member 34 is applied to the brake shoe 60, the brake shoe 60
The brake mechanism which increases the pressure applied to the lifting member 34 of 0.0 and 62 can adopt various constructions other than the construction shown in the drawings, such as the one shown in Japanese Utility Model Application No. 56-125738. Incidentally, the magnet holder may be fixed to the attraction plate 90, the attraction plate may be fixed to the lower end of the rod 78', and the positional relationship between the magnet holder and the attraction plate may be reversed.

As mentioned above, this study uses a permanent magnet 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. It is possible to eliminate the problem of sagging due to Therefore, it is possible to eliminate a state of play in which the brake arm is not driven even when the brake pedal is depressed when the gas spring is normal, and the brake release operation can be performed accurately. Further, by moving the magnetic force adjustment plate, there is an effect that the magnetic attraction force of the permanent magnet to the attraction plate can be easily adjusted.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the conventional plan, Figure 2 is an explanatory diagram of the same,
3 is a cross-sectional view showing a preferred embodiment of the present invention, FIG. 4 is a side view explaining the operation, FIG. 5 is a partially sectional front view explaining the operation, and FIG. 6 is a diagram explaining the operation. FIG. 7 is a sectional view showing another embodiment. 2... Lifting member, 4, 6... Brake shoe, 8
...Brake release pedal, 10...Spring, 12...
...transmission force escape mechanism, 14, 16...rod, 18
... Nut, 20 ... Foot lever, 22 ... Connection section, 30 ... Base, 32 ... Leg member, 34 ...
Lifting member, 36... gas spring, 38... horizontal pipe, 40... drawing board support frame, 42... lever,
44... Axis, 46... Brake release pedal, 50
... Brake arm, 60, 62 ... Brake shoe, 64, 66 ... Leaf spring, 74 ... Pin, 78
... Rod, 90 ... Adsorption plate, 96 ... Plate member,
98...Permanent magnet, 100...Magnet holder, 1
15...Magnetic adjustment plate.

Claims (1)

[Scope of utility model registration request] A leg member 32, a lifting member 34 supported by the leg member 32 so as to be able to rise and fall, and a gas spring 36 for applying elastic force upward to the lifting member 34.
Normally, the brake shoes 60 and 62 are connected to the elevating member 3.
4 to fix the elevating member 34 to the leg member 32 side, and when the downward moving force of the elevating member 34 is transmitted to the brake shoe 60, the brake shoe 60
a brake mechanism configured to increase the pressing force against the lifting member 34; a brake release pedal 46 for separating the brake shoe 60 of the brake mechanism from the lifting member 34; and a space between the brake release pedal 46 and the brake mechanism. and a transmission force escape mechanism that prevents the brake release movement of the brake release pedal 46 from being transmitted to the brake mechanism when the pressing force of the brake shoe 60 against the elevating member 34 exceeds a predetermined value. The transmission force escape mechanism is composed of a permanent magnet 98 and an adsorption plate 90 that is attracted to the permanent magnet 98 by magnetic force, and a magnetic force adjusting plate 115 made of a non-magnetic material is moved between the permanent magnet 98 and the adsorption plate 90. A safety device for an elevator platform, characterized in that the gap between the permanent magnet 98 and the adsorption plate 90 can be adjusted by moving the magnetic force adjusting plate 115.