JPH0450829Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a chair lifting device, more specifically,
This invention relates to a lifting device in which a pump is driven by operating a pedal, and a ram shaft is raised and lowered by hydraulic pressure.

[Conventional technology and problems]

As shown in Fig. 4, a conventional pedal-type elevating device for a chair for hairdressers, etc. has a ram shaft 2 in a housing 1 that can be moved up and down, and a pump located at the rear of the ram shaft 2 with respect to the front of the chair. A pedal 4 protruding toward the rear of the chair is pivotally fixed to the upper end of the housing 1 so as to be able to swing vertically.
An oil storage chamber 5 is provided in the upper part of the housing 1, and a lock mechanism 6 for the ram shaft 2 is provided above the housing 1, and the pedal 4 and the lock mechanism 6 are interlocked by a link mechanism 7.

In the pump 3, a piston rod 8 is slidably fitted into a cylinder chamber 9 provided in the housing 1, and the oil in the oil storage chamber 5 is pumped through the check valve mechanism 10 by raising and lowering the piston rod 8 by vertically swinging the pedal 4. is fed into the lower pressure chamber 11 of the ram shaft 2 through the ram shaft 2 to raise the ram shaft 2,
When the pedal 4 is depressed to the lowest position, the check valve mechanism 10 is pushed open by the piston rod 8, and the oil in the pressure chamber 11 is returned to the oil storage chamber 5 to lower the ram shaft 2.

Further, when the pedal 4 is pushed up to the highest position, the lock mechanism 6 is operated via the link mechanism 7, and the ram shaft 2 is fixed unrotatably.

By the way, the above-mentioned lifting device uses a relatively large amount of oil equal to the diameter of the pressure chamber x the stroke of the ram shaft to raise the ram shaft, and this amount must be stored in the oil storage chamber. This requires a large oil storage chamber, and conventionally, this oil storage chamber has been provided in the upper part of the housing as shown in FIG. 4, so there is a problem that the housing becomes large in diameter.

In addition, since the pump is located at the rear of the chair with respect to the ram shaft, the pivot shaft of the pedal that extends toward the rear of the chair can be attached to the front of the ram shaft, allowing the pump to move from the swinging fulcrum to the pump operating point. The problem is that the distance between the two pumps is long, the pedal swing angle for operating the pump is large, and the operability is poor.

This idea was made to solve the above-mentioned problems, and the purpose was to provide a lifting device that could reduce the diameter of the housing and reduce the pump operation stroke of the pedal. be.

[Means for solving problems]

In order to solve the above-mentioned problems, this invention has a cylindrical holder in which the ram shaft and the pump are installed in parallel inside a cylindrical housing, and the part of the ram shaft located inside the housing is installed inside the housing. An oil storage chamber communicating with the pump side is formed between the outer periphery of the holder and the inner periphery of the housing, and a passageway is provided on the peripheral wall of the upper end of the holder to return oil from the pressure chamber to the oil storage chamber when the ram shaft rises to its maximum. An oil hole is provided, and a pedal mounting shaft is rotatably supported by a bearing provided on the opposite side of the ram shaft across the pump at the upper end of the housing, and a pump pressing arm and a lock are attached to this pedal mounting shaft. The mechanism is equipped with an operating link and a pedal extending toward the ram shaft in the parallel direction of the ram shaft and pump.

[Effect]

When you move the pedal up and down within a specified range,
The piston rod of the pump moves up and down, supplying pressure oil to the lower pressure chamber of the ram shaft, and the ram shaft rises.

When the pedal is depressed to its lowest position, the pump's valve mechanism opens, the oil in the pressure chamber returns to the oil storage chamber, and the ram shaft descends.

When the pedal is pushed up to its highest position, the locking mechanism is activated and the ram shaft is fixed and cannot be rotated.

〔Example〕

Embodiments of this invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings.

As shown in the figure, the housing 21 is formed into a cylindrical shape with upper and lower ends closed, and a ram shaft 22 is installed inside the housing 21.
and the pump 23 are housed in parallel.

The ram shaft 22 is arranged at a position near the rear of the chair, and the portion located inside the housing 21 is a cylindrical holder 2 built into the housing 21.
4, and its upper end is connected to the housing 21.
The space below the ram shaft 22 in the holder 24 serves as a pressure chamber 25.

The pump 23 is located closer to the front of the chair than the ram shaft 22, and the upper end of the piston rod 27, which is biased upwardly by a spring 26, is connected to the housing 2.
The lower end of the piston rod 27 is fitted into a cylinder 28 provided at the lower part of the housing 21, and a check valve mechanism 29 is incorporated in the lower part of the cylinder 28. The chamber 25 and the inside of the cylinder 28 are connected via a check valve mechanism 29 and a passage 30.

Inside the housing 21 is a piston rod 27.
The surrounding space and the cylindrical space formed between the outer circumferential surface of the holder 24 and the inner circumferential surface of the housing 21 serve as an oil storage chamber 31, which secures the amount of oil necessary for raising the ram shaft 22.

An oil relief hole 32 is provided at the lower end of the ram shaft 22 and extends from the lower end surface to the outer circumferential surface, and the oil relief hole 32 communicates with the upper end of the holder 24 when the ram shaft 22 reaches the highest position. An oil passage hole 33 is formed to return the oil in the ram shaft 25 into the oil storage chamber 31 to prevent the ram shaft 22 from rising any further.

A bearing 34 is provided at the upper end of the housing 21 in a portion located on the front side of the chair relative to the pump 23, and a pedal mounting shaft 35 whose central portion is rotatably supported by the bearing 34 is provided at both ends of the pedal mounting shaft 35 facing toward the rear of the chair. A pedal 36 is attached that extends from the bottom.

The pedal 36 can swing up and down with the mounting shaft 35 as a fulcrum, and a U-shaped pump pressing arm 37 is fixed to the mounting shaft 35 and has a U-shaped planar shape, the tip of which touches the upper end of the piston rod 27. When the piston rod 27 is moved up and down, the pressing arm 37 swings together with the piston rod 27.
is moved up and down to force the oil in the oil storage chamber 31 into the pressure chamber 25.

A locking mechanism 38 is provided on the upper part of the housing 31 and is fitted onto the ram shaft 22, and the locking mechanism 38 and the pressing arm 37 are interlocked by a link mechanism 39.

The locking mechanism 38 has a screw shaft 40 horizontally mounted between the open ends of a forked member 42 that is fitted onto the ram shaft 22,
A nut member 41 fixed to the forked portion is screwed into the screw shaft 40, and the free end of the fork member 42 is pulled by the rotation of the screw shaft 40 when the pedal 36 is pulled up to the lock position A in FIG. The ram shaft 22 is tightened and locked in a non-rotating manner.

The elevating device of this invention has the above-mentioned configuration, and when the pedal 36 is moved up and down within the elevating range B shown in FIG. 1 with the seat member attached to the upper end of the ram shaft 22, the inside of the pressure chamber 25 Pressure oil is supplied to the ram shaft 22, and the ram shaft 22 rises intermittently.

When the pedal 36 is depressed to the lowered position C shown in FIG. returns to the oil storage chamber 31 via
The ram shaft 22 descends due to its own weight and load.

Further, when the pedal 36 is pushed up to the lock position A shown in FIG. 1, the rotation and elevation of the ram shaft 22 can be fixed.

〔effect〕

As described above, according to this invention, the part of the ram shaft located inside the housing is supported by the cylindrical holder built into the housing, so the cylindrical holder can be separated from the housing, and the cylindrical holder can be separated from the housing. Since the shaped holder only needs to have the strength to withstand the hydraulic pressure that raises the ram, the outer diameter can be made thinner and the outer diameter can be reduced, and the housing can be made smaller in diameter and smaller accordingly.

In addition, a pedal mounting shaft is provided at the upper end of the housing on the opposite side of the ram shaft across the pump, and the pump pressing arm and pedal are attached to this mounting shaft, so that the point of action that presses the piston is on the ram shaft and the pedal mounting shaft. Since it is located between the barrel attachment shafts and the pump pressing arm can be shortened, the swing angle of the pedal that drives the pump can be reduced, and the ram shaft can be raised efficiently.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view of the lifting device according to this invention, FIG. 2 is a cross-sectional plan view of the same, FIG. 3 is a rear view of the same, and FIG. 4 is a longitudinal sectional view showing the conventional lifting device. 21... Housing, 22... Ram shaft, 23...
...Pump, 24...Holder, 25...Pressure chamber,
27... Piston rod, 29... Check valve mechanism, 31
is oil storage chamber, 33...oil hole, 34...bearing, 35
... Pedal mounting shaft, 36 ... Pedal, 37 ... Pressing arm, 38 ... Lock mechanism, 39 ... Link mechanism.

Claims (1)

[Scope of utility model registration request] By moving the pedal up and down within a certain range, the pump is driven, supplying pressure oil to the lower pressure chamber of the ram shaft to raise the ram shaft, and by depressing the pedal to its lowest position, the pressure chamber is raised. In the chair lifting device, the ram shaft is lowered by returning oil to the oil storage chamber, and when the pedal is pulled up to the highest position, a locking mechanism is activated to fix the ram shaft unrotatably.
The ram shaft and the pump are assembled in a parallel state inside a cylindrical housing, and the portion of the ram shaft located inside the housing is supported by a cylindrical holder built into the housing, and between the outer periphery of this holder and the inner periphery of the housing. An oil storage chamber that communicates with the pump side is formed in the holder, and an oil passage hole is provided in the upper peripheral wall of the holder to return oil from the pressure chamber to the oil storage chamber when the ram shaft is raised to the highest level. The pedal mounting shaft is rotatably supported by a bearing installed on the opposite side of the shaft.
A chair lifting device characterized in that a pump press arm, an operating link of a lock mechanism, and a pedal extending toward the ram shaft side along the parallel direction of the ram shaft and the pump are attached to the pedal mounting shaft.