US2552624A - Door closing apparatus, including electrically driven gear pump and oscillating vanemotor hydraulic transmission - Google Patents

Door closing apparatus, including electrically driven gear pump and oscillating vanemotor hydraulic transmission Download PDF

Info

Publication number
US2552624A
US2552624A US49059A US4905948A US2552624A US 2552624 A US2552624 A US 2552624A US 49059 A US49059 A US 49059A US 4905948 A US4905948 A US 4905948A US 2552624 A US2552624 A US 2552624A
Authority
US
United States
Prior art keywords
plate
door
shaft
oscillating
motor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US49059A
Inventor
Frederick W Enzenbacher
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US49059A priority Critical patent/US2552624A/en
Application granted granted Critical
Publication of US2552624A publication Critical patent/US2552624A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15BSYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B15/00Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
    • F15B15/18Combined units comprising both motor and pump
    • EFIXED CONSTRUCTIONS
    • E05LOCKS; KEYS; WINDOW OR DOOR FITTINGS; SAFES
    • E05FDEVICES FOR MOVING WINGS INTO OPEN OR CLOSED POSITION; CHECKS FOR WINGS; WING FITTINGS NOT OTHERWISE PROVIDED FOR, CONCERNED WITH THE FUNCTIONING OF THE WING
    • E05F15/00Power-operated mechanisms for wings
    • E05F15/50Power-operated mechanisms for wings using fluid-pressure actuators
    • E05F15/53Power-operated mechanisms for wings using fluid-pressure actuators for swinging wings

Definitions

  • This invention relates to improvements in door closing apparatus including electrically driven gear pump and oscillating vanemotor hydraulic transmission, or the like, and is directed more particularly to improvements in operating mechanism for opening and closing doors and the like.
  • the principal object of the invention is the provision of operating mechanism for doors such as swinging doors and is characterized bymeans operable to open or close a door or to close or open said door whichever may be desirable. While the invention is described in connection with swinging doors, it will be understood that the mechanism is adapted for sliding and other doors or closures.
  • Fig. 1 is an elevational sectional view through an operating mechanism embodying the novel features of the invention
  • Figs. 2, 3 and 4 are sectional views on the lines 2-2, 3-3 and 4-4 respectively of Fig. 1;
  • Fig. 5 is an elevational view at small scale showing the operating mechanism of the invention operatively connected to a door.
  • a casing is represented by 2 which has a base 4 secured to its lower end and a cap 6 secured to its upper end to provide an enclosed housing.
  • the base is provided with openings 8 for receiving screws for securing the housing to a door frame ID, or the like, as shown in Fig. 5.
  • a tubular shaft [2 is journalled at its upper end in the cap by an anti-friction bearing I4, intermediate its ends by bearing I5 and at its lower end in a lower plate I 6 secured in the casing against rotation.
  • a shaft [8 is disposed in the tubular shaft l2 and is oscillatable in a bearing 20 at its upper end associated with the cap 5 and a bearing 22 at its lower end associated with the base 4.
  • a lever 24 is fixed to the upper end of the shaft 18 by means of a key 26 and a nut '28 in threaded engagement with said shaft, all as shown.
  • a rod 30 is pivoted at one end to a stud 32 of A lever 24 and at its other end said rod is pivotally connected to a bracket 3% which is secured to a door 36, see Fig. 5.
  • the door 35 is hinged at 33 to the door frame Ill for swinging movements between open and closed positions. As the lever 24 swings in one direction or the other the door 35 is opened or closed.
  • a rotor 48 is fixed to the shaft l2 and a stator 42 is fixed in the housing 2.
  • the said rotor and stator will be of ordinary construction and cooperate to form an electric motor preferably of the slow speed type and arranged so that when energized the shaft I2 will be rotated in one direction at slow speed.
  • a coil spring 44 is provided at the upper end of the housing and has one end. 46 secured to the lever 24 and its other end 43 secured to the cap 5, all as shown.
  • the spring is arranged to swing lever 24 and rotate shaft is in a direction opposite to that imparted thereto by the motor.
  • Plates 50, 52 and M are disposed above plate l6 within the housing and have pins or screws 56 passing therethrough to hold them against relative shifting movements and said plates are held against movement in the housing by being pressed therein or are otherwise anchored. Plate I6 is spaced above member 4.
  • a gear 58 is fixed to hollow shaft ⁇ 2 and is disposed in a bore 66 of plate 52.
  • a gear 62 has a shaft 64 journalled in plates 50 and 54 and H5, and is disposed in a bore 5% of plate 52 and is in mesh with gear 58. Portholes Hi9 and Ill) are provided in plate 52 for the passage of liquid from and to the gears.
  • Plate I6 see Fig. 2, is provided with openings 68 and 10.
  • Plate 54 is provided with openings 14 and I08 as shown in Fig. 3.
  • the pump and motor system is filled with oil.
  • a driven member 8!] disposed in the space 6 is fixed to shaft It by a key 82 or the like.
  • An abutment member I8! is attached to plate I6 by screws 91, see Fig. 2. Within it is an opening llll.
  • a plunger 99 with a disc type head is slidable in ill! and has a groove I85. Under the head of plunger 99 is a packing cs. Disposed at an angle to bore of the plunger is a plunger H34, which is pressed in groove its by a spring I03 backed up by adjusting screw I 62. This acts as a brake on plunger 99 to prevent it from slipping out of place.
  • Plunger 99 may be installed as shown or with head on opposite side of abutment member Ifll if it is desired to have pressure applied in reverse direction.
  • gears 58 and (i2 draw oil through openings 68 in plate I5, I98 in plate 1 and porthole H19 in plate 52' and force it out through porthole l H! in plate 52, openings 14 in plate 54 and opening iii in plate E5 to the space between abutment m1 and movable member cc, causing member 8!) to rotate thereby rotating shaft I8 and swinging lever 25 in one direction or with plunger $9 in opposite position and motor turning in opposite direction oil is drawn through openings iii in plate iii, M in plate 5 1 and porthole I if) in plate 52 and forced out through porthole I09 in plate 52, openings 38' in plate 5d and- 63 in plate 5 5 to space between abutment iii!
  • plunger 8 or 85 contacts plunger 99 and pushes it open at end of stroke. This allows oil to fiow through openings lil'i from behind member 88 to forward side as spring returns it to starting position. As member 89 reaches end of return stroke plunger 85 or 84 pushes plunger 99 closed so packing is pressed over openings it? and it is ready for next operation.
  • the motor on rotation brings about movement of member 8!! and shaft 52 so as to wing lever 24 in one direction for opening or closing the door and when the door is opened or closed, movement of the member as is arrested and spring id swings lever 2% in an opposite direction to close or open the door.
  • the motor may be energized in any suitable manner such a connections 92 extending therefrom to a power line 9% with a control switch 95 to open and close the circuit to the motor.
  • the apparatus In some cases it will be desirable to arrange the apparatus so that the motor is energized for closing the door while it is opened by the spring 44. In other cases it may be desirable to bring about opening of the door by energizing the motor and closing it by action of the spring.
  • Coupling construction for the hollow motor haft of a door swinging apparatus having a driven shaft oscillatable in the motor shaft comprisin in combination, a housing having a lower circular bore concentrically disposed relative to the longitudinal axes of the shafts, a lower cap closing the lower end of the bore, a first plate spaced upwardly from said lower cap and cooperating therewith to provide a closed lower chamber into which the driven shaft extends, a driven member in the chamber having a hub fixed to the driven shaft, an abutment in the chamber fixed to said first plate extending between said hub and the side of the chamber, superposed second and third and fourth plates transversely of the bore above said first plate and secured thereto, said third plate being provided with adjacent bores, a driving gear in one of the bores fixed to the motor shaft, a gear in the other of the bores in mesh with said driving gear, said third plate being provided with separate ports at opposite sides of and between said gears, said first and second plates being provided with communicating openings therethrough providing separate fluid passageways extending from the ports to

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Power-Operated Mechanisms For Wings (AREA)

Description

May 15, 1951 F. w. ENZENBACHER 2, ,6
DOOR CLOSING APPARATUS, INCLUDING ELECTRIC-ALLY DRIVEN GEAR PUMP AND OSCILLATING VANE MOTOR HYDRAULIC TRANSMISSION Filed Sept. 15, 1948 I 2 Sheets-Sheet 1 Fig.1. 2/
k y if w ffi W y FJHE.
J1 $7 if 17 JZQ fi ffl fi 8 J9 INVENTOR. I zdywzzggmz 1141; a r w May 15, 1951 F. w. ENZENBACHER OSING APPARAT 2,552,624 DOOR CL us, INCLUDING ELECTRICALLY DRIVEN GEAR PUMP AND OSCILLA'IING VANE MOTOR HYDRAULIC TRANSMISSION Filed Sept. 15, 1948 '2 Sheets-Sheet 2 INVENTOR. /2/Zm%x r 6 ant Patented May 15, 1951 UNITED STATES PATENT OFFIQE.
DOOR CLOSING APPARATUS, INCLUDING ELECTRICALLY DRIVEN GEAR PUMP AND OSCILLATING VANE MOTOR HY- DRAULIC TRANSMISSION This invention relates to improvements in door closing apparatus including electrically driven gear pump and oscillating vanemotor hydraulic transmission, or the like, and is directed more particularly to improvements in operating mechanism for opening and closing doors and the like.
The principal object of the invention is the provision of operating mechanism for doors such as swinging doors and is characterized bymeans operable to open or close a door or to close or open said door whichever may be desirable. While the invention is described in connection with swinging doors, it will be understood that the mechanism is adapted for sliding and other doors or closures.
With the foregoing and various other novel features and advantages and other objects of my invention as will become more apparent ,as the description proceeds, the invention consists in certain novel features of construction and in the combination and arrangement of parts as will be hereinafter more particularly pointed out in the claims hereunto annexed and more fully described and referred to in connection with the accompanying drawings wherein:
Fig. 1 is an elevational sectional view through an operating mechanism embodying the novel features of the invention;
Figs. 2, 3 and 4 are sectional views on the lines 2-2, 3-3 and 4-4 respectively of Fig. 1; and
Fig. 5 is an elevational view at small scale showing the operating mechanism of the invention operatively connected to a door.
Referring now to the drawings more in detail, the invention will be fully described.
A casing is represented by 2 which has a base 4 secured to its lower end and a cap 6 secured to its upper end to provide an enclosed housing. The base is provided with openings 8 for receiving screws for securing the housing to a door frame ID, or the like, as shown in Fig. 5.
A tubular shaft [2 is journalled at its upper end in the cap by an anti-friction bearing I4, intermediate its ends by bearing I5 and at its lower end in a lower plate I 6 secured in the casing against rotation.
A shaft [8 is disposed in the tubular shaft l2 and is oscillatable in a bearing 20 at its upper end associated with the cap 5 and a bearing 22 at its lower end associated with the base 4.
A lever 24 is fixed to the upper end of the shaft 18 by means of a key 26 and a nut '28 in threaded engagement with said shaft, all as shown.
A rod 30 is pivoted at one end to a stud 32 of A lever 24 and at its other end said rod is pivotally connected to a bracket 3% which is secured to a door 36, see Fig. 5. The door 35 is hinged at 33 to the door frame Ill for swinging movements between open and closed positions. As the lever 24 swings in one direction or the other the door 35 is opened or closed.
A rotor 48 is fixed to the shaft l2 and a stator 42 is fixed in the housing 2. The said rotor and stator will be of ordinary construction and cooperate to form an electric motor preferably of the slow speed type and arranged so that when energized the shaft I2 will be rotated in one direction at slow speed.
A coil spring 44 is provided at the upper end of the housing and has one end. 46 secured to the lever 24 and its other end 43 secured to the cap 5, all as shown. The spring is arranged to swing lever 24 and rotate shaft is in a direction opposite to that imparted thereto by the motor.
Plates 50, 52 and M are disposed above plate l6 within the housing and have pins or screws 56 passing therethrough to hold them against relative shifting movements and said plates are held against movement in the housing by being pressed therein or are otherwise anchored. Plate I6 is spaced above member 4.
A gear 58 is fixed to hollow shaft {2 and is disposed in a bore 66 of plate 52. A gear 62 has a shaft 64 journalled in plates 50 and 54 and H5, and is disposed in a bore 5% of plate 52 and is in mesh with gear 58. Portholes Hi9 and Ill) are provided in plate 52 for the passage of liquid from and to the gears.
Plate I6, see Fig. 2, is provided with openings 68 and 10. Plate 54 is provided with openings 14 and I08 as shown in Fig. 3.
The pump and motor system is filled with oil.
A driven member 8!] disposed in the space 6 is fixed to shaft It by a key 82 or the like.
Within member 8!! are two transverse bores 86 and 81 which carry plungers as and cushioned by spring 88 and 89 and are held and adjusted by screws 90 and ti.
An abutment member I8! is attached to plate I6 by screws 91, see Fig. 2. Within it is an opening llll. A plunger 99 with a disc type head is slidable in ill! and has a groove I85. Under the head of plunger 99 is a packing cs. Disposed at an angle to bore of the plunger is a plunger H34, which is pressed in groove its by a spring I03 backed up by adjusting screw I 62. This acts as a brake on plunger 99 to prevent it from slipping out of place.
Plunger 99 may be installed as shown or with head on opposite side of abutment member Ifll if it is desired to have pressure applied in reverse direction.
As the motor is energized so that shaft 12 is rotated, gears 58 and (i2 draw oil through openings 68 in plate I5, I98 in plate 1 and porthole H19 in plate 52' and force it out through porthole l H! in plate 52, openings 14 in plate 54 and opening iii in plate E5 to the space between abutment m1 and movable member cc, causing member 8!) to rotate thereby rotating shaft I8 and swinging lever 25 in one direction or with plunger $9 in opposite position and motor turning in opposite direction oil is drawn through openings iii in plate iii, M in plate 5 1 and porthole I if) in plate 52 and forced out through porthole I09 in plate 52, openings 38' in plate 5d and- 63 in plate 5 5 to space between abutment iii! and movable member as, causing member as to rotate in opposite direction to open or close door 36. When member 8d is rotated so as to partially close opening 68 or in, this restriction slows down travel, then plunger 8 or 85 contacts plunger 99 and pushes it open at end of stroke. This allows oil to fiow through openings lil'i from behind member 88 to forward side as spring returns it to starting position. As member 89 reaches end of return stroke plunger 85 or 84 pushes plunger 99 closed so packing is pressed over openings it? and it is ready for next operation.
The motor on rotation brings about movement of member 8!! and shaft 52 so as to wing lever 24 in one direction for opening or closing the door and when the door is opened or closed, movement of the member as is arrested and spring id swings lever 2% in an opposite direction to close or open the door.
The motor may be energized in any suitable manner such a connections 92 extending therefrom to a power line 9% with a control switch 95 to open and close the circuit to the motor.
In some cases it will be desirable to arrange the apparatus so that the motor is energized for closing the door while it is opened by the spring 44. In other cases it may be desirable to bring about opening of the door by energizing the motor and closing it by action of the spring.
This mechanism permits operation of door manually at any time. In case the cycle has not i been complete, the plunger 59 in abutment iii! will be open and the liquid is free to flow in either direction when pressure on the door moves member 8B. In case the cycle has been completed and the plunger as ha been pressed over'the openings fill, movement of member 8%! by pres sure on door will force the liquid through openings lii'i against the back of the disc type head on the plunger 99 and push it open.
The invention may be embodied in other specific forms without departing from the essential characteristics thereof. Hence, the present embodiments are therefore to be considered in all respects merely as being illustrative and not as being restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all modifications and variations as fall within the meaning and purview and range of equivalency of the appended claims are therefore intended to be em braced therein.
What it is desired to claim and secure by Letters'Patent of the United States is:
l. Coupling construction for the hollow motor shaft of a door swinging apparatus having. a
4 driven shaft oscillatable in said motor shaft which is urged in a certain direction by a spring comprising in combination, a housing having a lower circular bore concentrically disposed relative to the longitudinal axes of said shafts, a lower cap closing the lower end of said bore and a first plate spaced upwardly therefrom and cooperating therewith to provide a closed lower chamber into which said driven shaft extends, a driven member in said chamber having a hub fixed to said driven shaft and a part extending from said hub to the side of said chamber, an abutment in said chamber fixed to said first plate extending between said hub and side of said chamber, superposed second and third and fourth plates transversely of said bore above said first plate and secured thereto, said third plate provided with adjacent bores, a driving gear in one of said bores fixed to said motor shaft and a gear in the other of said bores in mesh with said driving gear, said third plate provided with separate ports at opposite sides of and between said gears, said first and second plates provided with communicating openings therethrough providingseparate fluid passageways extending from said ports to said lower chamber at opposite sides of said abutment, all adapted whereby a said motor shaft is rotated in one direction said gears displace fluid through one of said ports and passageways into said lower chamber at one side of said driven member to oscillate said member and driven shaft in one direction and opposite to said certain direction and arranged so that said driven member displaces fluid in saidchamber upwardly through the other passageway and port to said gears.
2. Coupling construction for the hollow motor shaft of a door swinging apparatus having a driven shaft oscillatable in said motor shaft which is urged in a certain direction by a spring comprising in combination, a housing having a lower circular bore concentrically disposed relative to the longitudinal axes of' said shafts, a lower cap closing the lower end of saidbore and a first plate spaced upwardly therefrom and cooperating therewith to provide a closed lower chamber into which said driven shaft extends, a driven member in said chamber havin a hub fixed to said driven shaft and a part extendin from said hub to the side of said chamber, an abutment in said chamber fixed to said first plate extending between said hub and side of said chamber, superposed second and third and fourth plates transversely of said bore above said first plate and secured thereto, said third plate provided with adjacent bores, a driving gear in one of said bores fixed to said motorshaft and a gear in the other of said bores in mesh with said driving gear, said third plate provided with separate ports at opposite sides of and between said gears, said first and second plates provided with communicating openings therethrough providing separate fluidpassageways extending from said ports to said lower chamber at opposite sides of I said abutment, all adapted whereby as said motor and driven shaft in onedirection and oppositeto said certain direction and arranged so that said driven member displaces fiuid. in said chamber upwardly through the other passageway and port to said gears, said abutment provided with an opening therethrough for the. flow of fluid ber for engaging and moving said valve to open position as said driven member approaches the end of its movement in said one direction.
3. Coupling construction for the hollow motor haft of a door swinging apparatus having a driven shaft oscillatable in the motor shaft comprisin in combination, a housing having a lower circular bore concentrically disposed relative to the longitudinal axes of the shafts, a lower cap closing the lower end of the bore, a first plate spaced upwardly from said lower cap and cooperating therewith to provide a closed lower chamber into which the driven shaft extends, a driven member in the chamber having a hub fixed to the driven shaft, an abutment in the chamber fixed to said first plate extending between said hub and the side of the chamber, superposed second and third and fourth plates transversely of the bore above said first plate and secured thereto, said third plate being provided with adjacent bores, a driving gear in one of the bores fixed to the motor shaft, a gear in the other of the bores in mesh with said driving gear, said third plate being provided with separate ports at opposite sides of and between said gears, said first and second plates being provided with communicating openings therethrough providing separate fluid passageways extending from the ports to the lower chamber at opposite sides of said abutment, all adapted whereby as the motor shaft is rotated in one direction said gears displace fluid through one of the ports and passageways into the lower chamber at one side of said driven member to oscillate said driven member and driven shaft in one direction and opposite to the said certain direction and arranged so that said driven member displaces fluid in the chamber upwardly through the other passageway and port to said gears.
FREDERICK W. ENZENBACI-IER.
REFERENCES CITED The following references are of record in the file of this patent:
UNITED STATES PATENTS
US49059A 1948-09-13 1948-09-13 Door closing apparatus, including electrically driven gear pump and oscillating vanemotor hydraulic transmission Expired - Lifetime US2552624A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US49059A US2552624A (en) 1948-09-13 1948-09-13 Door closing apparatus, including electrically driven gear pump and oscillating vanemotor hydraulic transmission

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US49059A US2552624A (en) 1948-09-13 1948-09-13 Door closing apparatus, including electrically driven gear pump and oscillating vanemotor hydraulic transmission

Publications (1)

Publication Number Publication Date
US2552624A true US2552624A (en) 1951-05-15

Family

ID=21957847

Family Applications (1)

Application Number Title Priority Date Filing Date
US49059A Expired - Lifetime US2552624A (en) 1948-09-13 1948-09-13 Door closing apparatus, including electrically driven gear pump and oscillating vanemotor hydraulic transmission

Country Status (1)

Country Link
US (1) US2552624A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2800323A (en) * 1951-10-02 1957-07-23 Pittsburgh Plate Glass Co Door-operating system
US3948000A (en) * 1974-07-25 1976-04-06 Ingenjorsfirman Besam Aktiebolag Hydraulic door openers
EP0087794A2 (en) * 1982-03-02 1983-09-07 Gian Luigi Gamberini Hydraulic power unit

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE623849C (en) *
US1883685A (en) * 1927-06-20 1932-10-18 Hugo Junkers Hydraulic clutch
US1984692A (en) * 1931-07-16 1934-12-18 Fred L Nichols Door operating mechanism
US2024300A (en) * 1933-09-02 1935-12-17 Harry C Miller Combined door-opener and doorcheck
US2025573A (en) * 1933-05-24 1935-12-24 Gen Electric Hydraulic operating mechanism
US2244929A (en) * 1939-10-21 1941-06-10 Edmund L Wall Variable speed hydraulic clutch

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE623849C (en) *
US1883685A (en) * 1927-06-20 1932-10-18 Hugo Junkers Hydraulic clutch
US1984692A (en) * 1931-07-16 1934-12-18 Fred L Nichols Door operating mechanism
US2025573A (en) * 1933-05-24 1935-12-24 Gen Electric Hydraulic operating mechanism
US2024300A (en) * 1933-09-02 1935-12-17 Harry C Miller Combined door-opener and doorcheck
US2244929A (en) * 1939-10-21 1941-06-10 Edmund L Wall Variable speed hydraulic clutch

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2800323A (en) * 1951-10-02 1957-07-23 Pittsburgh Plate Glass Co Door-operating system
US3948000A (en) * 1974-07-25 1976-04-06 Ingenjorsfirman Besam Aktiebolag Hydraulic door openers
EP0087794A2 (en) * 1982-03-02 1983-09-07 Gian Luigi Gamberini Hydraulic power unit
EP0087794A3 (en) * 1982-03-02 1984-09-05 Gian Luigi Gamberini Hydraulic power unit

Similar Documents

Publication Publication Date Title
US2276338A (en) Door operator
GB1337087A (en) Gate assembly
US2552624A (en) Door closing apparatus, including electrically driven gear pump and oscillating vanemotor hydraulic transmission
US2390882A (en) Declutching device for powerdriven butterfly valves
US2478481A (en) Hydraulic motor of the wobble plate type
US2003669A (en) Door closer
US1970008A (en) Doorcheck
US1997175A (en) Door closing mechanism
US3136509A (en) Railroad switch mechanisms
US2795414A (en) Window operating device
US2348460A (en) Combined hand and hydraulic valve operator
US2077747A (en) Power steering mechanism
US1751172A (en) Valve and valve-operating mechanism
US2756563A (en) Electrohydraulic motor mechanism
US3408035A (en) Flow control systems and operator therefor
US3948000A (en) Hydraulic door openers
US2433651A (en) Power steering gear
US2072203A (en) Power steering apparatus for vehicles
US1700848A (en) Apparatus for operating garage doors
US2210598A (en) Power clutch unit
US833940A (en) Double-acting door-check.
US2690765A (en) Hydraulic operating apparatus
US1120833A (en) Fluid-motor and retarding device therefor.
US2853292A (en) Power door operating system with door return action upon manual door movement
US1998103A (en) Electrohydraulic motor