US2618365A

US2618365A - Pneumatic hydraulically controlled door operating mechanism

Info

Publication number: US2618365A
Application number: US40706A
Authority: US
Inventors: Nils G Seagren
Original assignee: ASTRA ENGINEERING Co
Current assignee: ASTRA ENGINEERING Co
Priority date: 1948-07-26
Filing date: 1948-07-26
Publication date: 1952-11-18
Anticipated expiration: 1969-11-18

Description

NOV. 18, 1952 SEAGREN 2,618,365

PNEUMATIC HYDRAULICALLY CONTROLLED DOOR OPERATING MECHANISM Filed July 26, 1948 2 SHEETSSHEET 1 :E .L. INVENTOR. 7 N 5 15's agrerz ATTORNEY NOV. 18, 1952 N G SEAGREN 2,618,365

PNEUMATIC HYDRAULICALLY CONTROLLED DOOR OPERATING MECHANISM Filed July 26, 1948 2 SI-EETS-Sl-IEE'I 2 U Jim;

33 I T 7 5" r .4 4. I i INVENTOR.

\ I BY s ggrerz,

ATTORNEX Patented Nov. 18, 1952 PNEUMATIC HYDRAULICALLY CONTROLLED DOOR OPERATING MECHANISM Nils G. Seagren, South Pasadena, Calif., assignor, by mesne assignment-s, to Astra Engineering Company, a corporation of California Application July 26, 1948, Serial No. 40,706

4 Claims.

This invention relates to a device for pneumatically opening and closing doors together with hydraulic means for controlling the pneumatic operation of such doors.

While doors'generally are manually operated, there are many places and numerous instances where such manual operation is both inconvenient. and cumbersome. This is particularly the case in establishments such as hospitals and wherever wheel chairs, floor trucks, push carts and similar vehicles are to be moved through doorways which are fitted with normally closed doors, or where large trays and other bulky loads are to be carried through such doors.

It is the general object of the invention to provide a simple, inexpensive and conveniently operable device so designed, constructed and arranged that the operator of the vehicle pr the person carrying such load may actuate the mechanism of the invention to move the door without delaying, interrupting or otherwise interferring with the operation of the vehicle or transportation of such load. A further object of the invention is to provide a door opening mechanism which will instantly commence to swing the door into open position and, as it approaches fully open position, will check the movement thereof so as to bring the door gently into fully open position.

Another object is the provision of means for momentarily delaying closing movement of the door and for initiating such closing movement slowly thereby to offer the operator time to move the vehicle through and completely away from the closing door. A still further object is to provide. means for checking the final closing movement of the door, thereby to bring the door into closed position without bang or jar.

These and other objects of th invention, as well as the. many advantageous. features thereof, will be better understood from the following detailed description and by referring to the drawings, in which a preferred form of the invention is illustrated.

In the drawings:

Fig. l is a front elevational view of a door operating mechanism embodying the invention;

Fig. 2 is a substantially corresponding plan view of the device;

Fig. 3 is a side view, on a larger scale, of the pneumatic and hydraulic cylinder combination of the device;

Figs. 4 and 5 are detai1 views, on a still larger scale, of certain important elements of the cylinder combination; and

Fig. 6' shows a needle valve of the device, the function of which will be hereinafter fully described.

As indicated in the drawings, a door A is hung in a conventional framing B on hinges C and it is shown fitted with a bracket I at the top thereof in position pivotally to support the piston rod 2 of a cylinder combination. The latter terminates in a lug 3 which is pivotally hung in a bracket 4 of the wall B.

The cylinder combination is, as best indicated in Fig. 3, composed of two parts, namely a pneumatically actuated operating section 5 and a hydraulic movement-control mechanism 6. The section 5 includes a cylinder 1, the inner end of which is shown threaded to receive therein a screwplug 8, from which the aforenamed lug- 3 extends. A piston 9 is secured to the inner end of the piston rod 2 and it is by a spring [0 urged in the door closing direction indicated by the arrow II.

In a. cabinet [5 is mounted a pressure regulator I6 which, through a conduit I1, is in communication with a source of air under pressure. Since such source of compressed air is commonly found in establishments where the device of my invention is mostly used and because any suitable conventional air compressor may be employed, such is not illustrated in the drawings. Adjacent the pressure regulator I6 is mounted a valve l8, from one port of which leads a conduit 19 to the regulator l6, and a flexible conduit 20 extends from the valve to the inner end of the cylinder 1, through the screw plug 8. This valve is electrically operated and the operating mechanism is actuated by a person pushing a vehicle, carrying a load, or just walking toward the door. in any suitable manner.

Illustrative of a preferred form of electrical valve operating mechanism, I have, in Fig. 2, diagrammatically shown a pad 2i placed on the floor and extending such a distance from-both sides of the door opening as may be found most convenient for the purposes of the invention. Between this pad and the floor surface are placed contact members consisting of thin sheets 22, 2-3 of current conducting material forming the terminals of an electric circuit. Between these sheets and secured thereto are a number of equidistantly spaced discs 24 of insulating material, merely thick enough to maintain the sheets sufficiently spaced apart to maintain the circuit open. When so constructed, it is found that; pressure against the pad by the vehicle or the foot of the operator will bring the sheets into 3 contact with each other at some point or points between the discs thereby to close the circuit through a source of energy 23. A magnet 21 in the circuit is thereby energized to open a passage through the valve and the conduit for the pressure fluid to the cylinder 1, to cause the piston 9 to advance, against the tension of the spring l0, and quickly to move the door toward fully open position. The space between the

sheets

22, 23, at the outer edges thereof, is tightly closed by a strip 25 which also is made from insulating material.

It was above stated that one of the objects of the invention is to provide means for checking the movement of the door as it approaches fully open position. The piston rod 2 is, for this purpose, made with an enlargement 33 which, as the piston advances to open the door, enters into a recess 34 of a screw plug 35 which closes the end of the cylinder 6 and serves as a guide for the piston rod. This recess is slightly larger in diameter than the enlargement 33 of the piston rod. The cylinder 6 is filled with a liquid such as used in shock absorbers and when so filled it is found that the enlargement 33, upon entering the recess 34, is forced to expel the fluid from within the recess and in" so doing to check the movement of the piston rod as the door moves into fully open position.

The cylinders 5 and 6 are fastened together i by means of a connecting member 31, the ends of which are threaded to engage screw threads of the two cylinders, substantially as indicated in Fig. 3. It is noted that the end of this member which extends into the cylinder 6 is provided with a recess 38 of a size freely to receive an enlargement 39 of the piston rod for the purpose which will be explained presently. In addition, it is important to note that a conduit 43 interconnects the ends of the cylinder 6 at points directly in front of the recesses 34 and 3B. The piston rod is, between the

enlargement

33 and 39, made with a piston 36 which is freely fitted within the cylinder and, as the piston rod moves to open the door, advances Within the cylinder thereby gently to force the fluid therein through the conduit 40 to the rear end of the piston, a portion of the fluid being free to flow through the narrow annular space between the piston and the cylinder.

In order more completely to control the speed of opening movement of the door I have, in Fig. 4 shown the central control member of the piston rod made in two parts which are secured in position on the piston rod by means of pins or set screws 45, 46. A washer 42 is placed on the rod between these two parts and it is by a resilient gasket 43, of the commercially well known 0 type, held in contact with the rear end surface of the piston 36. A number of fine passages 44 are cut through the piston, but these passages are normally held closed by the washer 42. When the valve is thrown to initiate advance movement of the piston 36, it is found that the fluid in front of the advancing piston flowing through the passages 44 exerts sufficient pressure against the washer 42 to cause the latter to recede and so to uncover these passages sufficiently to relieve the pressure in front of the piston. The initial opening movement of the door will, for this reason and because the fluid also flows through the conduit 40 and past the piston, not be delayed. This movement continues until the enlargement 33 reaches the recess 34 whereupon, as above stated, further advancement is checked to bring th door to a sto gently. In other words, this combination constitutes a dash-pot controlling the final opening movement of the door.

In order better to control the speed of movement of the door, it is preferred to provide aneedle valve 4| in the conduit 40 for manual operation to adjust the opening of the passage through this conduit. The door will remain open until the vehicle, or the person passing through the door opening, or both, have cleared the pad 21, whereupon the circuit automatically opens to permit the valve 18 to return to its initial position and so to relieve the pressure within the cylinder 5. The spring I0 is now free to return the piston rod on the door to closing position, but this movement is delayed until the enlargement 33 leaves the recess 34, so that the initial closing movement of the door is effected slowly until the enlargement passes out of this recess. The closing movement continues at increased speed until the piston rod enlargement 39 enters the recess 33, similarly to check the final closing movement of the door. This completes the cycle of operation.

Since the enlargement 39 remains seated within the recess 38, it is found that subsequent opening movement would be initiated slowly, until the enlargement has passed out of the recess. Such delay is objectionable and provision is, for this reason, made for expediting the initial opening movement. Such means may tak the form of a check valve 3|] which is placed within the enlargement 34, substantially as indicated in Fig. 4.

It was above stated that the spring ll) quickly returns the door to closed position. I have found it advantageous, however, to provide pneumatic means for effecting the door closing movement. Illustrative of such means I have shown a second pressure regulator 50 placed within the cabinet I5. Air from the conduit l1 passes through this regulator and a conduit 52 to the other end of the pneumatic cylinder 1. This second regulator should be properly adjusted to effect the closing movement of the door at the required rate of speed. It is also important to note that, because this pressure is continuously maintained, the regulator It must be adjusted to provide sufficient pressure not only to overcome the pressure tending to close the door but also to open the door at the required speed. Where such pneumatic door closing arrangement is provided, the spring HJ may be omitted. A relief valve 53 is in communication with the conduit 52 and this valve should be set for a slightly higher pressure than registered by the regulator 50 in order to prevent waste of the pressure fluid but so that the fluid ahead of the piston 9 may discharge through this gelief valve during the opening movement of the cor.

In places where swinging doors are installed, it is sometimes found that a draft is present on the premises of sufiicient force to swing the door open and to maintain it partly open. When the pneumatic door closing arrangement of my invention is applied to a door in such places, it is found that it can be adjusted to maintain the door normally closed.

It is, of course, necessary to provide within the piston rod bearing packin designed to prevent leakage of the fluids within the cylinders, but as such are commonly used in devices of the type herein considered, it is not believed necessary to burden the drawings with illustrations thereof. Even when such packing is provided, it may be found that a slight leakage of fluid from the front end of the cylinder may occurand that if such leakage should occur, the result would be that the leaking fluid woulddrop from the end of the cylinder to the floor. It may, for this reason, he found advisable to fit a cap 60 over the threaded end of the plug 35, within which such slight amount of fluid as may leak through this plug would be free to accumulate. The cap is made with a passage 6| which, when the cap is screwed tightly in place, will take a. position at the top of the cap, as shown. The cap may from time to time be loosened to bring this passage to the bottom thereof and so to permit any slight accumulation of fluid to discharge therefrom.

The device of the invention, as above described, does not interfere with manual operation of the door which will continue to function in the conventional manner in case the operating mechanism should become ineffective, as by interruption of the electric circuit. But while I have in the foregoing described a preferred form of the invention, I do not wish to be limited to the exact sizes, proportions and arrangements shown, but reserve the right to embody therein modifications within the scope of the claims hereto appended.

I claim:

1. In a door operating mechanism, means for controlling the operation of the door comprising, a cylinder, a door check fluid within said cylinder, a closure for each end of the cylinder, each closure having in the inner surface thereof a cylindrical recess communicating with the space within the cylinder, a cylindrical member within the cylinder including a, central piston portion slidable within the cylinder, a head at each end thereof and reduced portions intermediate said heads and the central piston thereof, the heads being slightly smaller in diameter than the recesses of the closures, there being a passage through one of said heads, a check valve in said passage, and a by-pass conduit interconnecting the ends of the space within the cylinder.

2. In a door operating mechanism, means for controlling the operation of the door comprising, a cylinder, a door check fluid within said cylinder, a closure for each end of the cylinder, each closure having in the inner surface thereof a cylindrical recess communicating with the space within the cylinder, a cylindrical member within the cylinder including a central piston portion slidable within the cylinder, 9, head at each end thereof and reduced portions intermediate said heads and the central piston thereof, the heads being slightly smaller in diameter than the recesses of the closures, there being a passage through one of said heads, a check valve in said passage, a by-pass conduit interconnecting the ends of the space within the cylinder, and a valve controlling the passage through said conduit.

3 In a door operating mechanism, means for controlling the operation of the door comprising,

a cylinder, a door check fluid within said cylinder, a closure for each end of the cylinder, each closure having in the inner surface thereof a cylindrical recess communicating with the space within the cylinder, a cylindrical assembly comprising a shaft, two members fastened end to end on the shaft, one member having an enlarged portion thereon adjacent the other member and forming a piston freely slidable within the cylinder, said piston having passages therethrough, an annular plate on the other member, means urging said plate against the piston to close said passages, the members having heads at the ends thereof for passage into said recesses to check sliding movement of the assembly within the cylinder, and a by-pass conduit interconnecting the ends of the space within the cylinder.

4. In a door operating mechanism, means for controlling the operation of the door comprising, a cylinder, a door check fluid within said cylinder, a closure for each end of the cylinder, each closure having in the inner surface thereof a cylindrical recess communicating with the space within the cylinder, a cylindrical assembly comprising a shaft, two members fastened end to end on the shaft, said members having heads at the outer ends thereof for passage into said recesses to check sliding movement of the assembly within the cylinder, one member having an enlarged portion thereon adjacent the other member and forming a piston freely slidable within the cylinder, said piston having passages therethrough, the inner end of the other member being reduced in diameter to form a recess adjacent the piston, a washer in said recess, a resilient element in the recess urging the washer against the piston to close said passages, and a by-pass conduit interconnecting the ends of the space within the cylinder.

NILS G. SEAGREN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 522,508 Canet July 3, 1894 606,640 Bennik July 5, 1898 612,324 Frazier et al. Oct. 11, 1898 1,037,267 Knight Sept. 3, 1912 1,338,906 Coulson May 4, 1920 1,540,972 Weeks June 9, 1925 1,722,920 7 Hynes July 30, 1929 1,737,433 Rowntree Nov. 26, 1929 1,859,364 Haskell May 24, 1932 1,950,685 McGee Mar. 13, 1934 2,151,851 Briggs Mar. 28, 1939 2,395,027 Whisler Feb. 19, 1946 FOREIGN PATENTS Number Country Date 311,392 Italy Sept. 29, 1933