US3407598A

US3407598A - Hydraulically operated opening and closing device for doors or the like

Info

Publication number: US3407598A
Application number: US593128A
Authority: US
Inventors: Yokota Katutaro
Original assignee: ZENTSU DENKI KK
Current assignee: ZENTSU DENKI KK
Priority date: 1966-11-09
Filing date: 1966-11-09
Publication date: 1968-10-29
Anticipated expiration: 1985-10-29

Description

Oct. 29, 1968 KATUTARO YOKOTA 3,407,593

HYDRAULICALLY OPERATED OPENING AND CLOSING DEVICE FOR DOORS OR THE LIKE Filed Nov. 9, 1966 Fig.1

uvmzwwwzzzzzza V INVENTOR. 18 19 K4 t vraro Ya Kata BY Atprmf)! I United States Patent() 3,407,598 HYDRAULICALLY OPERATED OPENING AND CLOSING DEVICE FOR DOORS OR THE LIKE Katutaro Yokota, Tokyo, Japan, assignor to Zentsu Denki Kabushiki Kaisha, Tokyo, Japan Filed Nov. 9, 1966, Ser. No. 593,128 Claims. (Cl. 60--52) ABSTRACT OF THE DISCLOSURE An hydraulically operated door opening and closing device is shown in which two opposing pistons are rigidly connected by -a piston rod to be reciprocable in a cylinder and to define between them an oil chamber. Each piston has two opposed one-way valves mounted in it. A rotary oil pump is juxtaposed to one end of the cylinder and-is driven by a direct-connected motor. The pump is connected by two duets with respectively opposite ends of the cylinder. -A by-pass groove is provided in one wall of the cylinder to by-pass oil from one side of a piston to the other during travel of the pistons in the cylinder; and an adjustable throttle valve is provided to control the opening of an exhaust port which connects one end of the cylinder with the duct that leads from the pump to the opposite end of the cylinder.

This invention relates to a hydraulically operated opening and closing device for doors or the like.

The present invention has as its primary object to provide a hydraulically operated door opening and closing device comprising an operating cylinder, a pair of pistons fitted to the opposite ends of a piston rod reciprocable therein and each provided with a pair of one way valves at the head ends thereof, a hydraulic pump provided adjacent to one end of said cylinder and operative to deliver oil thereto, and a motor for driving said pump; said pairs of one-way valves being operable, in response to an opposing force developed in the body to be actuated by the present opening and closing device, to discharge part of the pressure oil into an oil chamber formed intermediate said pistons to circulate freely in the cylinder.

Heretofore, in door opening and closing devices of this kind using hydraulic pressure or compressed air, those equipped with means to control the speed of displacement of the opening and closing device, in response to an haphazard oppOsing force exerted on the door, as when a person had his hand pinched by the door or bumped thereby, were exceptional, and such means required much space or complex operating mechanism.

In contrast with these defects of conventional devices of this kind, the present invention provides a door opening and closing device which may be operated in response to an haphazard opposing force applied to the door, to minimize undue force imposed on the hydraulic system and make for safety, and which may be fitted within a narrow space because of its compact size.

The present invention will now be described in detail with reference to certain embodiments thereof as illustrated in the accompanying drawing.

In the drawing:

FIG. 1 is a longitudinal partial sectional view showing an embodiment of the hydraulically operated door open ing and closing device according to the present invention;

FIG. 2 is a transverse section taken on the line 'II-II of FIGyl;

*F-IG. 3 is a transverse section taken on the line III'-'-III of FIG. 1;

FIG. 4 is an explanatory view illustrating somewhat diagrammatically the operation ofthe hydraulic system according to the present invention; and

3,407,598 Patented Oct. 29, 1968,

Thus an intermediate oil chamber 29 is defined by the pistons 14, 14' and the wall of the cylinder 16, while

pressure oil chambers

1 and 17 are defined by the head of the left-hand piston 14 and the head of the right-hand piston 14 respectively. Pressure oil is delivered selectively to the pressure oil chamber 17 via exhaust port 31 of the rotary pump 32 and to the pressure oil chamber 1 via a second exhaust port 21 of the pump 32 and an oil duct 18.

A by-pass 19 for adjusting the flow of oil is provided between the right hand end of cylinder 16 and oil duct 18 and flow of pressure oil from the rotary pump 32 is adjustable by screwing the flow-adjusting screw 20 into the by-pass 19. As shown in -FIG. 1, a seat 15' for oneway relief valve 26 is provided on the head end of the piston 14' and the one-way relief valve 26 operable in one direction is provided in the bore 9 thereof. In addition, another one-way relief valve 5 operable in the opposite direction is provided on the same side of the piston 14'. The one-way relief valve 26 is normally biased towards the left by means of a spring 7 and the force of the spring 7 i s so adjusted that the one-way relief valve 26 associated therewith may be opened by the percussive force imposed by the pressure oil, or as the oil pressure in the hydraulic system is raised excessively due to the opposing force that may be produced fortuitously as the door is opened or closed, but not by the normal level of the oil pressure in the hydraulic system. On the other hand, the one-way relief valve 5 is normally biased to the right by means of a spring, thereby to block the oil circuit behind the valve 5. A side opening 8 opening into the intermediate oil chamber 29 is provided in the bore 9. A bifurcate lever 11 is connected at its forked end to a lug 10 formed centrally of the rod 12 and at its other end to a shaft 28 formed integral with the lever 30 provided externally of the hydraulic system of the present opening and closing device and rotatable to actuate the lever 30. A by-pass groove 13 is provided in a suitable position extending along the internal wall of the cylinder 16 over an extent lessthan the spacing between the opposing pistons 14, 14'. In designing, the cross-sectional area of the bypass groove is to be determined suitably by taking the pressure and flow of oil passing therethrough and the speed of displacemanually reciprocating the lever 24 connected to the piston rod 25.

The rotary pump 32 is connected with the operating cylinder 16. In the embodiment illustrated, the pump 32' is connected to the right-hand side of the operating cylinder 16. In any case, the exhaust port 21 of the pump is connected by duct 18 to the pressure oil chamber 1, and the other exhaust port 31 to the pressure oil chamber 17. The shaft 22 of the motor 23 for driving the pump 32 is connected to or formed integral with the shaft of the pump 32. The oil is circulated in the confined path'and the hydraulic driving system and the mechanism to build hydraulic pressure in the hydraulic driving system constitute a unit. Motor 23 may be a DC motor or AC commutator motor with commutator 35. Its direction of rotation is reversible by cutting over the electrical connection thereof and reversing the direction of the exciting current.

In FIG. 3, numeral 36 designates a drain plug for pressure oil and numeral 37 a seat for drain plug 36 formed integral with the operating cylinder 16.

Explaining the operation of the present opening and closing device with reference to the block view of FIG. 4 and also to FIGS. 5 and 6, pressure oil is delivered from the operating cylinder 16 into the pressure oil chamber 1 via the port 21 and the oil path 18 by rotation in one diretcion of the motor 23 and of the rotor 33 of the pump 32, as shown in FIG. 4 by the arrow marks in the solid lines, and the left-hand piston 14 is displaced to the right.

The bifurcate lever 11 engaging with the lug on the rod 12 is set into motion, thereby to rotate the shaft 28.

Thus, the lever 30 connected to the outermost end of the shaft 28 is swiveled, and the door 39 connected to the lever 30 through link 41 (FIG. 6) may be opened or closed.

If, during the displacement of the piston 14 to the right, a person has his hand caught by the door 39 or has it bumped thereby, and, as a consequence, the oil pressure in the oil chamber 1 has been raised suddenly, pressure oil in the chamber 1 will force the one-way valve 26 open, against the resistance of the spring 7, and escape to the intermediate oil chamber 29. The excessive oil pressure in the chamber 1 may thus be reduced, and furthermore, pressure oil Will flow into the chamber 17 via the by-pass groove 13 provided on the cylinder Wall or back into the pump 32 via the one-way relief valve 5, so the oil may be circulated freely irrespective of the rotation of the pump 32. As the intermediate oil chamber 29 has a relatively larger volume, and serves as the oil storage tank, the percussive force exerted by the pressure oil is lessened in passing through the chamber 29 and the oil is circulated in the system under reduced pressure via the one-way relief valve 5..

Even if the door that is being opened or closed hydraulically is retained forcibly for a considerable period of time, the oil will flow in a free state without producing excess percussive force which may result in the destruction of the hydraulic system, and the overload that may be applied on the pump 32 and the motor 23 may be avoided.

In case pressure flow of oil from the motor 23 and the pump 32 is reversed, as shown by the dotted line arrows of FIG. 4, the pressure of oil in the chamber 17 will be increased and the piston 14 forced to the left in much the same way as the piston 14' is forced to the right under the pressure of oil in the chamber 1. If the opposing force is applied to the door 39, the one-way relief valves 26, 5 on the opposite side of the cylinder will come into operation, and pressure oil will flow in a free state via bypass groove 13, intermediate oil chamber 29, and by-pass 19 for adjusting the flow of oil provided on the same side of the cylinder. Hence, the pump 32 and the motor 23 will idle without excessive pressure being developed in the hydraulic system.

The by-pass 19 for adjusting the flow of oil is adjusted to moderate distribution or relivery of oil to both the

pressure oil chambers

1 and 17 and control the speed of displacement of the

opposing pistons

14, 14 irrespective of the constant speed rotation of the pump 32 if the flowadjusting screw is screwed in a proper amount into the by-pass 19.

While the pump 32 as illustrated is a trochoid type rotary pump, it may also be a gear pump or other reversible type rotary pump.

FIG. 5 shows in fragmentary plan view the opening and closing device according to the present invention as applied to an automobile door in which the swingable lever is pivooted at one end to the main operating cylinder 16 and at the other end to the link 41, the outermost end of the link 41 being pivoted to the hinge 51 provided to the fixed wall member 52. If the motor and the pump mounted adjacent to the cylinder 16 is rotated, and the outermost end of the lever 30 is moved to the right, the link 41 pivoted to the lever 30 is swiveled and the door 39 is opened as shown by the dotted line. By reversing the above-mentioned operation, the door 39 may be returned to the former position. In the initial stage of the door opening operation, the subsidiary swivel lever 24, which is here connected by a link 40 with the door lock 38 will come into play to release the lock 38. Numeral denotes the door hinge.

FIG. 6 shows an embodiment wherein the present opening and closing device is applied to the door of a house or. building. In this embodiment, the operating cylinder along with the driving motor and the pump is attached as a unit to the fixed wall member 52 and the door 39 is opened by the operation of the pivot arm 30 and the link 41 to the position shown by the dotted lines.

As above described, in operating the hydraulically operated door opening and closing device of the present invention, a pair of one-way relief valves are fitted to each of the opposing pistons interconnected by a piston rod reciprocating in the operating cylinder and an intermediate oil chamber is defined between said pistons to receive oil from the pressure oil chambers and reduce the excessive pressure in the hydraulic system, while a by-pass groove is provided on the cylinder wall to control the flow of oil and to regulate the displacement speed of the opposing pistons in the operating cylinder. Moreover, according to the present opening and closing device, the pressure oil is circulated in a confined path and the rotary pump and the motor for driving the same are mounted close to the operating cylinder and if an opposing force is imposed haphazardly on the door by someone using this device, part of the pressure oil will be circulated in a free state in the hydraulic system without undue drive force being produced thereby.

In the event that a person has his hand caught by the door, or has bumped into the door accidentally, the hydraulic system operates smoothly without undue force being exerted on any portion thereof, and possible injury in such contingencies may be avoided. In addition, because of its compact size, the opening and closing device may be fitted within a narrow space as in an automobile door frame.

What is claimed is:

1. A hydraulically operated opening and closing device for doors or the like, comprising a cylinder, a pair of pistons interconnected by a piston rod reciprocable in said cylinder, a lug formed centrally of said piston rod, a bifurcated lever engaging at the forked end thereof with said lug formed on the piston rod and rigidly connected at the other end to one end of a rotatable shaft to rotate a lever which is secured at one end to said shaft and in turn is connected at its other end to a door or the like, a rotary pump operative to build oil pressure in the cylinder and having a pair of discharge ports, each communicating with a pair of pressure oil chambers formed between the opposite wall members of the cylinder and said pistons, and a reversible type driving motor operative to rotate said rotary pump reversibly, each of said pistons having a one-way control valve operative to discharge part of the pressure oil from one of said pressure oil chambers into an intermediate oil chamber formed in the cylinder by said pistons as percussive force is applied to a piston from the side of said one of said pressure oil chambers, and another one-way control valve operative to reverse the pressure oil stored in the intermediate oil chamber under reduced pressure into said one of said pressure oil chambers.

2. A hydraulically operated opening and closing device for doors or the like, as claimed in claim 1, wherein said rotary pump operative to build hydraulic pressure in the cylinder is mounted on one end of said cylinder and the reversible type motor operative to rotate said rotary pump reversibly is mounted in juxtaposition to said pump.

3. A hydraulically operated opening and closing device for doors or the like, as claimed in claim 1, further comprising a cylinder of a short length mounted to one end of the first-mentioned cylinder and communicating therewith, a piston rod reciprocable in said short length cylinder and having a piston at one end thereof, and a manually operated lever pivoted to the free end of said rod.

4. A hydraulically operated opening and closing device for doors or the like, as claimed in claim 1, wherein said cylinder is formed with a longitudinal groove along the inner wall member thereof, said groove being operative to communicate one of said pressure oil chambers with said intermediate oil chamber as the piston is displaced in one direction or the other and to discharge part of the pressure oil therethrough to adjust the speed of displacernent of the pistons.

5. A hydraulically operated opening and closing device for doors or the like, as claimed in claim 1, wherein an oil path connecting the pressure oil chambers to the discharge ports provided on the rotary pump is provided with means to control the flow of oil discharged to said oil path.

References Cited UNITED STATES PATENTS 1,120,833 12/1914 McElroy.

1,998,103 4/1935 Smith.

2,095,286 10/ 1937 Riach 60--52 2,900,791 8/1959 Kinsey 60-52 EDGAR W. GEOGHEGAN, Primary Examiner.