JPH047300A - Brake for elevating cargo - Google Patents

Abstract

PURPOSE:To transmit only the rotation of shaft at the time of lowering of a cargo support member to a member to be controlled so as to reduce energy consumption by forming a face to receive control through a frictional member pressing a face on the surface of a member to be controlled capable of rotating independent from an elevation shaft. CONSTITUTION:A frictional member 10 arranged on a threaded shaft 4 connected to a drive source 5 is used under an always compressed condition to the surface of a member to be controlled 30. The shaft 4 is rotated by the drive source 5 in the direction to raise a cargo support member at the time of raising a cargo, but the rotation in the direction is not transmitted to the member 30 owing to one-way transmission means 40. Despite the friction member 10 is compressed to the member 30, the shaft 4 (and thus a drive source 5) does not receive the control force. It is thus possible to reduce the consumption of output and energy of the drive source.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake suitable for a rotationally driven cargo lifting device.

[Prior Art] In a cargo lifting device, a drive source such as a motor rotates a shaft, and the rotational motion is converted into linear (lifting) motion by a screw, rack and pinion, etc., and lifts and lowers the cargo. A brake to stop or brake the descent of the cargo is usually placed on that axis. Electromagnetic type brakes that operate in conjunction with the drive source when the drive source stops are known as common circumferential brakes, but manual brakes are often used in non-stationary cargo lifting equipment. has been done. In the case of non-stationary equipment that is not used in a fixed location, it is often necessary to rely on battery power, so low power consumption is required.
In addition, a manual type is preferred because it is trouble-free.

Also in the cargo lifting device disclosed in Japanese Patent Publication No. 52-18970, a manual type brake that acts on a rotating shaft is used as a brake for braking the lifting and lowering of cargo. The device described in the publication is suitable for transporting cargo, including loading and unloading onto trucks and going up and down stairs.A screw shaft connected to a motor as a drive source is mounted vertically (up and down) on a frame with wheels.
In addition, a lifting frame having a nut member screwed onto a screw shaft and a cargo support member is assembled so as to be movable up and down along the wheeled frame. The cargo, ie, the lifting frame, is raised and lowered based on the rotation of the screw shaft, and braking is performed by the frictional force of a manual brake against the screw shaft.

Fig. 7 shows the brake described in the above publication, in which a brake band (strap) 10° is wound around the brake drum 30°, which is provided integrally with the above-mentioned screw shaft 4, and its end A braking force adjustment means 20° consisting of a link 21°, a bolt 25°, a handle 23°, etc. is installed between the frame 2° and the military wheel. By turning the handle 23° and pulling the bolt 25° to the right in the figure, the link 21' is displaced around the pivot 21a°, and the band lO° is tightened on the surface of the drum 30', producing a considerable braking force. bends to the drum 30°, that is, the axis 4°. According to the bulletin, in order to keep the cargo at a constant height when the motor is not started and to prevent the cargo from descending suddenly when unloading, this brake uses a 23° rotation position of the handle to adjust the band 10°. The resulting braking force is adjusted in advance so that it is comparable to the weight of the cargo, and the braking force is constantly applied to the 4° axis. When the motor is stopped, the cargo is supported by the braking force of the brake, and when the motor is started with a force greater than that of the window, the shaft rotates and the cargo is raised and lowered.

[Problem M to be solved by the invention] As mentioned above, the manual brake in a rotationally driven cargo lifting device employs a method in which a braking force of a set strength is constantly applied to the shaft by a friction member. However, these conventional brakes had the following problems.

b) Braking force is always acting on the shaft, so in order to lift the cargo, a large output equivalent to the sum of the cargo's heavy electricity and the above braking force is required from the drive source (motor, etc.). There is waste in terms of equipment specifications and energy consumption. The reason why the brakes are kept on all the time is that while the drive source is typically started and stopped frequently during cargo lifting operations, the manual brakes are released and re-applied accordingly. This is because it is difficult to do so. However, higher-grade equipment specifications not only increase the cost of the lifting device, but also increase the weight and make it difficult to handle.Also, if the energy consumption of the drive source is high, the same energy source (batteries, etc.) will be used.
Considering the fact that the maximum amount of work per session is small, it can be said that this issue (a) is difficult to ignore.

Although there is a means to adjust the braking force, it is virtually impossible to instantly increase the braking force because, for example, the steering wheel (23° in FIG. 7) must be suddenly rotated. Therefore, the braking force should always be set to be larger than the weight of the cargo so that the cargo does not fall when the drive source is stopped.

On the other hand, when unloading cargo, a force equivalent to the difference between the braking force and the cargo weight is required as the output of the drive source, and too strong a braking force is bad for energy consumption, so when setting the braking force , careful adjustment is essential so that it falls within a narrow range that is not less than the cargo weight.

SUMMARY OF THE INVENTION An object of the present invention is to provide a brake that exerts little braking force on the shaft when lifting cargo, thereby reducing the required output power and energy consumption of the drive source of the cargo lifting device. Further, the present invention (claim 2) also provides a brake that can apply sudden braking to stop the cargo suddenly, and therefore allows easy braking force setting in advance.

[tJ, Means for Solving the Problem] The brake for a cargo lifting device of the present invention (claim 1) brakes the rotation of a shaft for lifting and lowering a cargo lifting member using a friction member (for example, a brake band or a shoe). A braking system in which a surface that receives braking by the pressing of a friction member is formed on the surface of a braked member (such as a brake drum or a disc rotor) that can rotate separately from the above-mentioned shaft,
A one-way transmission means (for example, a ratchet or various one-way clutches) is provided between the braked member and the shaft to transmit only the rotation of the shaft when the cargo support member is lowered to the braked member.

As described in claim 2, in the above-mentioned brake, the brake drum is used as the braked member, a brake band is wound around it as the friction member, and one end of the band is pulled to apply braking to the drum. ■ A lever that is operated from the movable end position to one side; ■ A set of engaging members that connects one end of the band to the lever and has an adjustment when the lever is in the movable end position; ■ A lever that is operated in the direction in which the band is pulled. A spring is interposed between the lever and the band to generate an elastic force, and an operating means includes a spring deflection setting piece that can adjust the elastic force of the spring when the lever is at the movable end position. , it is also good to connect it to one end of the band.

[Function] The brake of the present invention, which is installed on a shaft connected to a drive source in a cargo lifting device, is normally used with the friction member always pressed against the surface of the braked member, and has the following effects on the lifting device. bring about.

1) Keeping objects at a constant height: In lifting equipment, even if the drive source is stopped, a rotational force is applied to the shaft in the direction of lowering the cargo support member based on the weight of the cargo, etc., but this brake The rotation of the shaft in that direction is transmitted to the braked member via the one-way transmission means, and is braked by the friction member pressed against the surface of the braked member. Therefore, if the braking force is adjusted to an appropriate strength in advance, the cargo and the support member thereof can be maintained at a constant height by the brake.

2) To suppress the descending speed of the cargo 2 As mentioned in l) above, the rotation of the shaft is transmitted to the braked member and subjected to braking,
If the braking force from the friction member is slightly small when the drive source is stopped, or if a worker pushes the cargo support member downward, or if the drive source is started in a direction that lowers the support member, the downward force may be suppressed. The cargo (and its supporting members) slowly descends due to a force that exceeds the power and is equivalent to the difference between the two.

3) Do not apply braking to lift the cargo. In the lifting device, the shaft is rotated by the drive source in the direction of lifting the cargo support member, but due to the one-way transmission means, the shaft is not rotated in that direction. Since this is not transmitted to the braking member, the shaft (and therefore the drive source) does not receive the braking force caused by the friction member, even though the friction member is pressed against the member.

In other words, point 3) is largely different from conventional brakes (see Figure 7), and provides advantages in terms of the required output of the ε power source and energy consumption.

Further, the brake according to claim 2 is provided with the above l) and 2) by the brake band tightened on the surface of the brake drum.
- It achieves the effect of 3), but also realizes the related effect of 4) and 5) below. That is, 4) Adjustment of braking force strength: In this brake, the elastic force of the spring C is normally transmitted to the engaging member (■), so that the lever (■) comes to the movable end position and the brake band moves to the lever. be drawn closer. In this state, since the engaging member has some play, the band is attracted solely by the elastic force of the spring, regardless of the rigidity of the engaging member. This attraction causes the band to be tightened to the surface of the brake drum and generates a braking force, so the strength of the braking force can be determined by arbitrarily setting the spring deflection using the setting piece (■) above to determine the elastic force. Adjustment is possible by

5) Applying sudden braking to the lifting and lowering of cargo: When the lever, which is normally at the movable end position, is operated to one side, the above-mentioned spring first expands and contracts, and the play of the engaging member becomes zero, After that, the rigidity between the band and the lever due to the above-mentioned engaging member etc. is used without using the elastic force of the spring.
The operating force of the lever is transmitted to the band. In other words, if the lever is operated rapidly, after an instant, a strong braking force that does not involve a spring can suddenly brake the lifting and lowering of cargo. For this reason, the strength of the braking force that has been adjusted in advance may be somewhat less than the weight of the cargo, and conventionally no strictness is required for the prior adjustment of the braking force.

[Embodiment] An embodiment of the present invention is shown in FIGS. 1 to 4. FIG. 1, FIG. 2, and FIG. 3 are a front sectional view, a plan view, and a plan view sectional view, respectively, of a brake for a cargo lifting device. Moreover, FIGS. 4(a) and 4(b) are a front view and a side sectional view of a cargo transporter equipped with the brake as a cargo lifting device.

The cargo transporter l shown in Fig. 4 has a lift frame 3 built into a transport frame 2 with wheels 2a, and is similar to the device described in the aforementioned publication (Special Publication No. 52-In2O).
This is a device used to transport cargo A (particularly transportation that involves lifting and lowering). The cargo A is placed on the cargo support member 3a formed integrally with the frame 3, and when a worker pushes (or pulls) the transporter 1 while rolling the wheels 2a, the cargo A is transported by the frame. By moving the lift frame 3 up and down with respect to 2, the cargo A can be lifted and lowered for loading and unloading onto a truck.

As a structure for vertically moving the frame 3 relative to the frame 2, a motor 5 as an ε power source is attached to the frame 2, and connected to the motor 5, a screw shaft 4 or an upper bearing 4 is connected to the motor 5.
The rack is passed vertically to the frame 2 via a. The elevating frame 3 is built to slide vertically relative to the frame 2, and also has an integral nut member 3b that is screwed into the threaded portion of the shaft 4, so that the shaft 4 can be moved by the motor 5.
It moves up and down as it rotates. The overall method of using the transporter L for transporting cargo is the same as the device in the above-mentioned publication, including the procedures for loading and unloading cargo A onto a truck and going up and down stairs. (The description will be omitted here.)

The motor 5 is activated by the battery 6 attached to the frame 2 to move the cargo A up and down, but when the motor 5 is stopped, the transporter 1 is is equipped with a characteristic brake 8 shown in FIGS. 1 to 3. The brake 8 is a band brake (band type brake) that applies braking force to the output shaft 5a of the motor 5 and the screw shaft 4 connected thereto, and is configured as follows.

a) First, as shown in FIG.
An inner cylinder portion 41b that connects the end g4a of the motor 5 to the output shaft 5a of the motor 5, and an outer edge portion 41 that projects outward at the lower part of the inner cylinder portion 41b.
A transmission body 41 integrally formed with c was fitted over both the end portion 4a and the output shaft 5a.

b) The cylindrical brake drum 30 is slidably rotated relative to the inner cylinder portion 41b of the transmission body 41.
Inserted. The drum 30 is a braked member that receives braking from a brake band 10, which will be described later, and has ratchet teeth 46 shown in FIG. 3 formed at its lower portion.

C) By attaching the pawl 44 shown in FIG. 3 near the outer edge portion 41c of the transmission body 41 so as to be able to swing around the bolt 43, and engaging it with the leaf spring 45 provided on the outer edge portion 41c. , the tip 44a of the pawl 44 was engaged with the ratchet teeth 46 of the tram 30. Since the pawl 44 cannot swing counterclockwise in the figure from the state in which it is engaged with the teeth 46, the above members (numbered in the 40s) collectively function as the one-way transmission means 40. That is, when the transmission body 41 rotates counterclockwise in the figure along with the screw shaft 4 due to the action of these members, that is, when the frame 3 descends.
Therefore, the rotational force is transmitted to the drum 30 via the teeth 46.

d) As a friction member for applying braking to the F ram 30, as shown in FIG. 2, a liner lob is applied to the metal band 10a, and one brake pad 10 is wound around the outer peripheral surface of the drum 30, and the operating means 20 described in e) below is used. Connect with 1.

e) Attach to both ends of bunt 10 2 m & 21
b is connected to the link plate 21c, and one pin 21b is connected to the - set of engagement members, that is, the bracket 22.
Connect to the operating lever 2 via the nut 23 and butterfly bolt 25. Further, as shown in FIG. 1, a collar 23λ is formed at the rear end of the nut 23 (left end in the figure), and a coil spring 24 is formed between the collar 23λ and the tip 22λ of the bracket 22.
was compressed and installed. On the other hand, the lever 27 is made swingable around a support shaft 27a provided on the transport frame 2 (see FIG. 4), and the state shown in FIG. Installation f. The operating means 20 configured in this manner has the following functions.

That is, the nut 23 has the lever 27 in the lock 28.
In the normal state when it hits, its tip (right end in the figure) 23b
The butterfly bolt 25 is aligned so that there is a gap between the front end 222L of the bracket 22 and the engagement member between the pin 21b and the lever 27. Soto 22 C”) inside (1'l
Because the collar 232L cannot be rotated, the butterfly port 2
When 5 rotates, the screwing position force changes. k)tl
When the lever 27 is at the movable end position when it is pulled by force,
When you turn the butterfly bolt 25 while holding m 25 a, the nut 23 moves back and forth (left and right in the figure) together with the collar 23a, which is the setting piece for the deflection (compression amount) of the spring 24, and the elastic force of the spring 24 is changed. By doing so, the tightening of the brake band 10 under normal conditions requires a force (i.e., the brake 8
braking force) is adjusted. Also, subtract shi/<-27 (
4), after the spring 24 is further compressed by the above-mentioned amount, the tip 23b of the nut 23 hits the tip 22& of the bracket 22, and the remaining force is to operate the lever 27. is directly transmitted to the pin 21b and becomes a braking force for the bunt 10.

In the brake 8 configured as described above, the normal braking force of the brake band 10 in d) can be adjusted in advance to an extent commensurate with the weight of the cargo A by turning the butterfly bolt 25 shown in e) above. If you keep it, the above u), b), C)
1) When the motor 5 is stopped, the rotation of the screw shaft 4 in the downward direction of the lifting frame 3 is braked to maintain the cargo A at a constant height; 2) The motor 5 and cargo A together with lifting frame 3.
3) When raising cargo A, the braking force applied to the screw shaft 4, which is rotated by the motor 5, is reduced to zero to reduce unnecessary resistance. It becomes possible not to produce any. This 3) is because the one-way transmission means 40 does not transmit the rotation of the screw shaft 4 (and transmission body 41) in the direction of raising the frame 3 to the brake drum 30. 1. Requires less output and power consumption. In other words, this transporter 1
Even with a small capacity No<・Nona 1 No 6, a relatively large amount of work can be done.

Further, this brake 8 can apply sudden braking to the threaded shaft 4 (by manually operating the brake lever 27 in e) above.
The braking force is set in advance to be smaller than the weight of cargo A (in this case, there is an advantage that the required output of motor 5 is less when lowering cargo A), and cargo A is kept constant. Even if it cannot be held at the same height, it can be compensated for by simple manual operation.

Regarding the brake 8, the above-mentioned operating means 20 may have the configuration shown in FIG. 5 or 6, for example, according to the invention. In the operating means 120 of FIG.
By turning the wing nut 123, the r of the spring 124 is
By setting the deflection (amount of extension), the normal braking force of the brake band 10 can be adjusted in advance. The brakes can be applied. On the other hand, according to the operating means 2201 in FIG.
It can be adjusted by setting the compression
<-) By turning 227, sudden braking can be applied.

Furthermore, if sudden braking by lever operation is not required, the operating means of the conventional brake (see FIG. 7) may be tightened by 20 degrees, and the brake band may be tightened onto the brake drum by a simpler means. As a result, even if sudden braking is not applied, by constantly applying an appropriate braking force, the effects 1), 2), and 3) (that is, the effects according to claim 1) are similarly brought about.

Furthermore, the brake shown in claim 1 can be realized by other than a band brake. For example, a disc brake type may be used in which the brake drum is replaced with a disc rotor and a brake band is replaced by a pad that is inserted between calipers. The built-in one-way transmission means is not limited to ratchets, and various one-way clutches including sprag clutches can be used.

Needless to say, the brake of the invention can be widely applied not only to the type of transporter shown in the embodiment but also to various lifting devices that lift and lower cargo based on the rotational force of a shaft.

Effect of mouth invention 2.

The brake for a cargo lifting device of the present invention exerts an appropriate braking force when the cargo tries to descend, but does not create resistance when lifting the cargo, so the lifting device equipped with the brake is easy to operate. At the same time, power efficiency is improved. Therefore, even if the lifting device is equipped with a small (small capacity) and lightweight drive source and energy source,
This will allow you to handle a sufficient amount of work.

Further, the brake according to the second aspect of the present invention can easily apply sudden braking to stop the cargo if necessary, so the normal braking force that should be adjusted and set in advance may be set to be slightly smaller than the weight of the cargo. This means that the braking force has a wide range of appropriate settings and adjustment work is easy, and that the lifting device can lower the cargo with an extremely small output.

[Brief explanation of the drawing]

1 to 4 are drawings relating to one embodiment of the present invention. Figure 1 is a front cross-sectional view of the brake for cargo lifting equipment (detailed view of a portion of Figure 4), and Figure 2 is its plan view (■ in Figure 1).
-■ arrow view), and Figure 3 is a planar cross-sectional view (m in Figure 1).
-■ sectional view) and FIGS. 4(λ) and (b) are a front view and a side sectional view of a cargo carrier equipped with the brake as a cargo lifting device. FIG. 5 and FIG. 6 are sectional views showing other embodiments related to claim 2, respectively. On the other hand, FIG. 7 is a sectional view showing a conventional brake. 1...Carrier (cargo lifting device), 3a...Cargo support member, 4...Screw shaft, 5...Motor (drive source), 8...
・Brake, 10...brake band (friction member),
20・120・220...operating means, 24・124・
224... Spring, 27, 127, 227...
Lever 30... Brake drum (braked member), 40
...One-way transmission means, A... Cargo. Figure 6

Claims (1)

[Scope of Claims] 1. A brake that is installed in a cargo lifting device in which a cargo support member moves up and down based on the rotational force of a shaft connected to a drive source, and that brakes the rotation of the shaft with a friction member, the brake comprising: A surface that receives braking by pressing the member is formed on the surface of a braked member that can rotate separately from the above-mentioned shaft, and between the braked member and the shaft, there is a surface that receives braking only when the cargo support member is lowered. What is claimed is: 1. A brake for a cargo lifting device, characterized in that the brake is provided with a one-way transmission means for transmitting the torque to a braked member. 2. A brake drum is used as the braked member, a brake band is wrapped around it as the friction member, and one end of the band is pulled to apply braking to the drum. (a) It is operated from the movable end position to one side. a lever; (b) a pair of engaging members that connect one end of the band to the lever and have play when the lever is in the movable end position; (c) a lever that is configured to generate an elastic force in the direction of pulling the band; a spring interposed between the ends of the band; (d) an operating means having a spring deflection setting piece capable of adjusting the elastic force of the spring when the lever is at the movable end position; connected to one end of the band; The brake for a cargo lifting device according to claim 1, wherein the brake is provided as follows.