US2368722A - Door operator - Google Patents

Description

Feb. 6, 1945. J, R. NEWKIRK DOOR OPERATOR Filed 001;. 29, 1943 2 Sheets-Sheet 1 INVENTOR. John R-NzwKlr-K- Feb. 6, 1945. J NEwKlRK 2,368,722

DOOR OPERATOR Filed Oct. 29, 1943 2 Sheets-Sheet 2 INVENTOR. John R- New Kirk.

BY (A Patented Feb. 6, 1945 UNITED STATES PATENT OFF-ICE noon orl'n'a'roa John a. Newkirh, Railway, N. 1., asaignor to National Pneumatic Company, New York, N. Y., a corporation of West Virginia Application October 29, 1943, Serial No. 508,195

3Claims.

This invention relates to power operated doors and is particularly adapted for use on doors which are diiilcult to start open for any reason.

- The main object of this invention is to provide .as an addition thereto and an improvement -thereon of means for holding a door open in a system of the type disclosed and claimed in my copending application Serial No. 481,107, filed March 30, 1943 for "Door operator, and now United States Patent No. 2,343,316, issued March '1, 1944.

The generaloblect of this invention is to provide with a power door operator arranged and constructed so as to automatically break the door open a short distance as an incident to the normal actof opening the door, means for holding the door open as long as may be desired.

Other and more detailed objects of this invention will be apparent from the following descripton of one embodiment thereof as made in connection with the attached drawings.

This invention resides substantially in the combination, construction, arrangement and relative location of parts, all as will be described in detail below.

In the accompanying drawings,

Figure 1 is a diagrammatic and schematic front elevational view of a door in combination with the operator of this invention;

Figure 2 is a longitudinal, central, cross-sectional view through the door engine used in the combination of this invention;

Figure 3 is a similar view of the gear train mechanism interconnecting the engine with the door operating levers; and

Figure 4 is a horizontal cross-sectional view through the door frame with some parts broken away showing the mechanism for holding the door open.

Doors for use in many places are frequently so heavy or are employed under such conditions that persons wishing to pass through the doorway find it dimcult to get the door started in its opening movement. For example, the end doors of railway vehicles which are air conditioned are often diillcult to open for one or more of several frequently encountered conditions. In the first place, these doors are relatively massive and heavy requiring considerable eifort to start them in their opening movement. In the next place, passengers are commonly-in the act of opening the door during the deceleration of the train, making it necessary to overcome the inertial resistance of the door to opening while the train is decelerating. Finally, the air conditioned railway cars frequently have a slightly greater than atmospheric pressure condition in the interior thereof which iurther adds to the diiliculty of "breaking" the door open. In accordance with this invention a power operating device is arranged so that as an incident to the act of starting the door open, the power operator for closins the door supplies for a short interval of time sufllcient power to start the door open after which it is relatively easy to complete its opening movement.-

The complete system herein disclosed results from the addition to an arrangement as above described and disclosed in my above mentioned copending application, which includes means formechanically holding the door in full open position and for maintaining the door operating engine open to exhaust, that is the same condition in which it is put at the timeit breaks" the door open, as explained above.

Referring to Figure 1, a door is illustrated at I hingedly mounted at 2 in the door opening. 1 As viewed in Figure 1 it is intended that the door open away from the side from which it is viewed in this figure. Mounted above the door on the adjacent frame is a diflerential air engine 3 having as a structural part a gear box or gear train 4. A short vertical shaft 5 is connected to the gear box at one end and at the other end to a lever 6 which is pivotally connected to a lever l in turn pivotally attached to the door by means of a plate or bracket 8. Pressure fluid, such as compressed air is supplied from a, suitable source, not shown, through a pipe I I having a control valve l2, an air strainer l3 and a needle valve arrangement I! all of common and well known construction, to a valve Ill having a solenoid operator 9. This valve in turn is connected by a pipe It to the end of the large cylinder of the diiierential engine. The magnet valve is very well known in this art and is of the type disclosed in United States Patent No. 1,849,516 at Figure 37. This is a so-called exhaust type of valve which, when-its solenoid is de-energized, connects pipe H to pipe It to maintain the pressure in the cylinder of the engine. When the solenoid 9 is energized, the valve it shifts to cut off the connection between pipes II and I6 and to open pipe it to exhaust.

One terminal of the solenoid winding is grounded'and the other is connected by means of wire I! to a switch l8 mounted on the door, which switch is supplied through the other lead to the positive side of a grounded-current source, not shown.

Switch 18 is arranged on the door so as to be valve operator operated by a push plate I! which is pivotally mounted by means of'the plate 28 on the door. This p sh plate, as illustrated, is frequently used in power operated doors and forms. The doorknob 2| on the other side of the .door has a shaft passing through the door and invention is shown in full detail in Figures 2 and.

3. It is a differential engine having a large cylinder 22 closed at one end by a cap 25 which has a threaded port to which the pipe- I 5 connects. The other end of the cylinder is provided with a reducing sleeve 21 internally threaded for attachment to the other end of cylinder 22 and for at? tachment to one end of the smaller cylinder 28. The other end of the cylinder 28 is externally threaded to receive the internally threaded end 30 of the gear housing 4.v Within the larger cylinder 22 is a piston assembly comprising the head 32 and the integral cylindrical housing 33 of substantial diameter so as to render the opposite sides of the head of different effective areas. Secured to the other end of the housing 33 is attached a small piston 38 for the cylinder 28 which is secured to the housing by means ofa double ended stud bolt 34. This bolt has a coupling eye 35 by means of which it is pivotally connected to the rack member 50 in the gear housing 4. The piston 35 is provided with the usual cup washer or backing 31 of some suitable flexible material. In a similar way a cup backing or washer 38 of flexible material is clamped onto the piston head 32 by means of a threaded plug 39. The plug 39 has a large central passage in which is slidably mounted the tubular member 49 which has a central passage of different diameters to form a seat 42. A spring 4| lies within the housing 33 and engages one end of the tubular member 40 to hold it in the position shown in Figure 2.. A ball is arranged to engage the seat 42 and a transverse pin 44 serves to limit the movement of the ball from its seat. The smaller bore of the tubular member is provided with a tube 45 which is threadedly secured therein and acts to hold a disc member 46 on the tubular member and a suitable seat disc 41 therein made of suitable material. The valve thus formed is adapted to cooperate with the seat 43 on the inner face of the cap 25. This cap has a passage 49 opening into the large cylinder outside of the diameter of the valve 41 and into the space defined by the seat 58 which is in communication with the threaded port in the cap. The rack member 50 has a rack 5| upon one face positioned to engage a gear 52 secured to the shaft 5 previously mentioned. An idler roller 53 engages the opposite face of the rack to hold its teeth in engagement with the teeth of the gear 52.

b As is clear from Figure 1, the gear housing 4 is mounted on the end of the cylinder 28. The engine is provided with a clamp 23 having an attach-ment plate 24 by means of which the engine may be mounted.

The particularly novel feature of this invention is illustrated in Figures 1 and 4. Mounted on the wall framing the door opening in which the door I is mounted, is a device 54 comprising a mechanical arrangement for holding the door open and a switch for controlling the solenoid magnet 9. Mounted on the door on the may 888111116 many side towards which the door opens is what may 76 assays:

be termed a catch member 51. Mounted on the adjacent wall in a position to become operatively associated with the catch member 51, is the combined keeper and switch device 54. as diagrammatically illustrated in Figure 4. This device includes a suitable housing within which are pivotally mounted at a pair of arms 55, which are v51 enters at its pointed end between the free ends of levers 59, pushing them aside until it reaches a point where the springs 5| can snap the levers 59 over the head of the catch member 51. This device also includes a switch 58 comprising a pair of flxed contacts and a movable contact positioned to be engaged by the head of the catch member 51 so as to. be closed when the door is mechanically held in open position. The positive lead of the current source is connected by wire 55 to one of the fixed contacts of the switch 58, while the other fixed contact is connected by wire 55 to the wire I! going to the solenoid operator 9.

The operation of the device will now be described upon the assumption that th door is closed, solenoid 9 is de-energized, and the engine is in the position shown in Figure 2 with air supplied to the left hand end of the large cylinder 22 by reason of the connection of pipe II to pipe it by valve In. It will be noted that no pressure fluid is supplied directly to thespace between the two pistons as in the usual case in the operation of differential pressure fluid engines. However, the fluid pressure does enter this space by seeping around the piston cup 38. It will be noted that the creation of a pressure condition in the left hand end of cylinder 22 will cause the application of fluid pressure to the piston cup 38 from the left towards the right contrary to the manner in which pressure fluid is usually supplied to piston cups. The result is that air, if it be the pressure fluid, can seep around the piston cup 38 from the left to the right, during closing, to build up a balanced pressure condition in the chambers on opposite sides of the piston 32. It will be recalled that this is the normal condition of the apparatus with the door closed. The air which is trapped between the pistons is forced into a smaller space during the completion of the closing movement of the door and, therefore, cushions the final closing movement of the door to prevent slamming of it.

Should a person desire to go through the doorway from the side from which Figure 1 is viewed, he will move up to the door and apply pressure to the push plate l9 which is a normal gesture of one wishing to open a door which swings away from him in opening. A comparatively light pressure will cause the push plate to move towards the door and close switch I 8. It may be noted that one approaching the door from the other side would grasp the doorknob 2| and start to pull it to open the door causing the same movement of the push plate I 9. The closing of switch l8 completes the circuit of the solenoid 9 in an obvious manner which operates valve III to cut off pipe II from pipe l5 and connect pipe 5 to the atmosphere. The left hand end of cylinder 22 of the engine is almost instantaneously freed of all pressure fluid so that the pressure fluid to the right of the large piston becomes trapped. This is so as the trapped pressure fluid will expand the piston cup 38 when the pressure drops in the large cylinder. The removal of the pressure on the left hand face of the large piston will permit the compressed air trapped between the two pistons to move the entire piston assembly to the left a short distance. This causes the withdrawal of the rack 50 towards the left (Fig. 3) and the rotation of shaft 5 in a clockwise direction. This movement of the shaft causes the door to open from four to six inches through the connecting levers 6 and I. The person going through the doorway continues to push on the plate I9 to finish the opening movement of the door which is a relatively simple operation now that the door has been started open. As long as pressure continues on the plate, the large cylinder is open to exhaust and no resistance is offered by the engine to the opening of the door until 41 seats on 48. The final movement of the piston assembly is then retarded since the remainder of the air in cylinder 22 is forced out through the restricted port 48. This insures that the final opening movement is retarded. The door may be held the large cylinder 3 with pipe ll.

open as long as desired by gently pushing on the plate 19 or pulling on the doorknob 2|. 7

After the person has passed through the door and released the push plate, a spring, not shown, such as is commonly used with such devices, swings it away from the door a. short distance to its normal position allowing the switch l8 to return to its normal open position. This de-energizes solenoid 9 and valve l0 moves back to connect pipe II with pipe l6. To continue the descri tion, it will be first necessary to note that when the door has been fully opened the piston assembly will have moved to the extreme left in Figure 2 during a portion of which movement the tube 40 will be stationary because the valve 41 has engaged the seat 48. The final movement of the piston assembly will, therefore, compress spring 4| and also act to resiliently cushion the termination of the door opening movement.

Going back now to the connection of pipe II to l6, it will be seen that air will be supplied into the left hand of the cylinder 22 through the passage in member 40 around the ball valve 43. Air will also pass around the ball valve 43 into the housing 33, and into cylinder 22 through the plus 39 around the member 40 as well a through port 49 in cap 25. The piston assembly continues its motion to the right until valve 41 opens when the air directly enters cylinder 22 to complete the closing of the door and the'holding of it shut under pressure until the next operation. If for any reason the pressure between the pistons is lower than that in cylinder 22, additional air will leak past the piston cup 3!, as previously .described, to equalize 1t and prepare the door for its next opening movement.

The operation of the mechanism for holding the door open is no doubt clear from the foregoing description thereof but brief reference is again made thereto. It will be recalled that the door can be held open-by continuing to push on the plate or bars II, but should one wish the door to remain open while he is free to move about, heneedonly ushthedoortothepointwhere thecatch i'lisgrlppedbythearmsll. These solenoid operator 9 energized and hence valve III operated, so that the large cylinder 3 is open to exhaust. Aside from any natural tendency of the door to close the mechanical catch need only be strong enough to hold the door against the effort of whatever air is trapped between the pistons that close'the door. These parts may be proportioned so that when it is time to close the door a light pull on the door will release its catch from the spring pressed arms 59. At the same time switch 58 will close, de-energizing the solenoid operator 9 so that valve 10 can reconnect The door will then close, as previously described.

From the above description it will be seen that the system herein disclosed comprises an arrangement having all the desirable functions of a door operating mechanism of this type. An important aspect of the invention is that this operation is secured with an exceedingly simple apparatus combination which differs from some equivalent system in that relatively few parts are required. of very simple construction. This apparatus is adapted to a long continued operation with little maintenance expenses and a minimum of possibility of disarrangement. Another advantage is that there is no danger of injury to persons using the door such as has been encountered in the past in the use of power opened doors since most of the opening operation is accomplished manually.

Those skilled in the art will readily appreciate that considerable changes in details of the mechanism herein disclosed can be made without departing from the novel subject matter herein disclosed. Forexample, in the event that it is not thought necessary to cushion the final opening movement of the door, this may be accomplished by eliminating the cushioning mechanism disclosed herein while still retaining substantially all or the advantages of the invention. 1 do not,

therefore, desire to be strictly limited by the disclosure herein given for purposes of illustration, but rather to the scope of the claims granted me.

What is claimed is:

l. A door operator comprising in combination a movably mounted door, a diflerential door engme connected to said door, means when energized for controlling the exhaust of pressure fluid from the large cylinder of said engine and for supplying pressure fiuid to both cylinders when deenergized, means for energizing said controlling means, whereby when said large cylinder is exnausted the air in the other cylinder operates the engine to open the door a short distance, means including a mechanical latching device composed of a catch on the door and a keeper on an adjacent support Ior holding the door open, and means for maintaining the energization of the means for exhausting fluid pressure from the engine.

2, In the combination of claim 1, said means for energizing said controlling means being mounted on the door.

3. In the combination of claim 1, said means for maintaining the energization of the means ror exhausting pressure fluidirom the engine including circuits and a switch actuated by said catch for maintaining the energiaatlon of the means for exhausting pressure fluid iron the engine, while the door is held open.

JOHN R. W

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