US 2920338 A
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H w. FALK DOOR CLOSER 7 Jan. 12, 1960 Filed Oct. 5. 1956 INVENTOR Hare/a 14/. a//1 ATTORNEY United States Patt DOOR CLOSER Harold W. Falk, Minneapolis, Minn. Application October 5, 1956, Serial No. 614,250 3 Claims. (Cl. 16-66) This invention relates to an improvement in door closers and deals particularly with a means of pretensioning the door closer so that it will act properly when installed.
In the construction of door closers of the type used to close screen doors and the like, it is necessary that the closer be mounted so that there is some closing tendency on the door after it has been closed so as to insure the proper operation. As the springs which are used to close the door are quite powerful due to the short leverage which is employed, it is diflicult to mount the closer in place while the spring is under tension. It is possible to mount one bracket upon the door frame and to mount another bracket on the door at a predetermined distance from the first bracket and to measure the distance so that the closure plunger is not at its extreme position when the door is fully closed. However, it is much simpler to provide some means of holding the plunger in a proper position as it is mounted so as to insure the proper relationship between the supporting brackets.
In the past this has been accomplished through the use of a spring clip which partially encircles the plunger rod and holds the plunger from moving into its extreme position toward which it is urged by the spring. This clip is maintained in place while the closer is mounted so that there is a constant tension against the door when it is fully closed. When the closer has been mounted, the'door is swung toward open position and the spring clip removed. After the spring clip has been discarded, it does not form a stop to remove tension from the closer when the door is closed.
While this structure operates effectively for its intended purpose, the use of such a clip comprises an additional expense in the manufacture as the clips are only useful until the door is mounted and are then discarded. It is an object of the present invention to provide a means of eliminating this extra expense while still accomplishing the same results.
In a closer of the type described, an angular bracket is provided which is slidable on the plunger rod. This bracket has a laterally extending arm engageable with an end of the closer. When the closer engages this arm it pivots the angle member on the plunger rod so that the angle member will not move and so that the angle member forms a stop for the closer casing. By providing suitable indicia on the plunger rod, it is possible to pull the rod outwardly until a suitable mark is uncovered, to place the angle member at this mark, and to permit the plunger rod to move into the cylinder until it engages the angle member. At this point there is the proper tension upon the spring within the cylinder to maintain the door in closed position and the closer may be mounted while the plunger rod is in this position.
A feature of the present invention resides in the fact that the mark, or marks, on the plunger rod may be in the form of grooves or slight indentations in the rod to provide a positive engagement between the angular bracket and the rod. As the bracket is held in an 2 adjusted position by friction, there is a slight possibility that the bracket will slide slightly after it is adjusted. By providing slight notches or grooves in the piston rod into which an edge of the angle member may engage, any such difliculty may be avoided.
An added feature of the present invention resides in the fact that the rod may be provided with a series of notches so that the tension of the spring may be set in accordance with the weight of the door to be operated by the closer. In other words, if the door to be closed is relatively heavy and requires considerable force to close, the initial tension upon the spring. may be increased by initially placing the angle member in one predetermined position. If the door is of medium weight, the angle member may be set at an intermediate position. If the door is extremely light-such as certain of the aluminum doors, less initial tension is required and the angle member may be set at a third predetermined position.
A further feature of the present invention resides in the plunger construction which is employed. During recent years plungers have been equipped with a pair of washer-like discs between which an O-ring is located. Diificulty has been experienced in arranging these rings so that movement of the plunger in one direction is relatively unimpeded while movement of the plunger to provide a space between these in the opposite direction is definitely checked; In the present construction this dificulty is eliminated by providing an aperture in the plunger washer on the side of the plunger opposite the closer spring and in providing a space between the washers inwardly of the O-ring. As the plunger moves toward closed position, air trapped within the plunger flows through the opening in the washer and outwardly against the O-ring tending to expand the O-ring against the cylinder surface. Upon movement of the closer to open the door, suction created behind the plungertends to reduce the diameter of the O-ring and to permit the door to be easily opened.
A further feature of the present invention resides in the provision of an automatic valve capable of opening if the pressure in the closed end of the closer becomes excessive. To accomplish this result, the plunger includes a pair of washers, one of which is offset so as washers at their periphery and between which the O-ring extends. The washer adjoining the flat washer of the pair comprises a flat flexible resilient washer of cork or other suitable material. A reinforcing washer sandwiches the flexible washer between the second washer of the pair and the reinforcing washer. The spring acts against the reinforcing washer and normally holds the flexible washer against the O-ring supporting washers. However, one or more small openings are provided through the flat washer of the pair and if the pressure within the closed end of the cylinder exceeds the spring pressure, the pressure of air through this passage may be suflicient to flex the flexible washer and to permit the escape of the excess air.
These and other objects and novel features of the present invention will be more clearly and fully set forth in the following specification and claims.
In the drawing forming a part of the specification:
Figure 1 is a top plan view of a door closer, showing the manner in which it is used.
Figure 2 is a longitudinal sectional view of .the same.
Figure 3 is a perspective view of the angular bracket or stop member of the closer.
The door closer is indicated in general by the letter A and is used to connect a door B to its door frame C. A hinge 10 is provided connecting thedoor B to. the frame C. As is usual practice in closers of this type, the closer is mounted to a bracket 11 secured by: screws or other suitable means 12 to the parting stop 13 form- Patented Jan. 12, 1960 3 ing a part of the door frame C near the hinged edge of the door. The bracket 11 supports a pivot 14- which extends through a flattened end 15 of the door check plunger rod 16.
A bracket 17 is mounted upon the door B at a point laterally spaced from the point of attachment of the bracket 11. This bracket 17 is notched as indicated at 1.9 to accommodate a cooperable bracket 29 on the end of the cylinder 21 into which the plunger rod 16 extends. The manner of connection, while not or" interest in the present invention, is illustrated in Figur- Z of dra n" ing. The connection is fully described in my copending application for patent for door check, Serial No. 399,544, filed December 21, 1953, now Patent 2,812,533, dated November 12, 1957.
The cylinder 21 is provided with an inturned annular flange 22 which terminates in the cylinder opening 3. A reinforcing plate 24 is mounted internally of the cylinder and a gasket 25 seals this plate with respect to the inturned flange 22. The plate is provided with a central axial internally threaded opening The bracket 2'1) is provided with a concave end 2? which fits against the flange 22.. A threaded plug 3% having an enlarged head 31 extends through an opening 32 in the concave portion 29 of the bracket 20, through the aperture 23 and is threaded into the internally threaded aperture 27 to provide an end closure for the cylinder.
The plug 36 is internally threaded and accommodates a bolt 33 which may be sufficiently loose to permit some escape of air thereby. The flow of air' past the bolt 33 depends upon the degree to which this bolt is threaded into the plug. A spring 34 is interposed between the bolt head and the plug to hold the bolt 33 in an adjusted relation.
A spring retaining member 35 is provided at the op posite end of the cylinder 21 from that described. In the particular form of construction illustrated, the spring retainer includes a sleeve portion 36 which fits slidably within the cylinder 21 and which is connected by an offset 37 to a smaller diameter portion 39. A split retaining ring 40 is supported in an annular groove 41 in the cylinder 21 and engages against the offset 37 to hold the string retainer in place. A ring-shaped flange 42 is provided on the end of the smaller diameter portion 39 and acts to hold one end of the spring 43 in position. The other end of the spring engages against the plunger which is indicated in general by the numeral The plunger 44 includes a first Washer 45 which includes a ring-shaped inner portion 46, an offset portion 47, and a ring-shaped outer portion 4?. An opening Si is provided through the oflset 47. A flat washer 51 is provided adjoining the washer .5 and the offset is of proper dimensions so that an Oring 52 may be accommodated between the washers. A small passage 53 is provided through the washer 51.
A flexible washer 54 lies against the washer 51 and a reinforcing washer 55 is provided outwardly of the flexible washer 54. The spring 43 engages against the reinforcing washer 55.
With this arrangement, it will be seen that as the spring urges the plunger toward the left end of the cylinder as viewed in Figure 2, air from the left hand end of the cylinder flows through the passage 50 and tends to expand the O-ring 52 against the cylinder wall. However, if excessive pressure is built up, this air will flow through the opening 53 and flex the flexible washer 53- sufliciently to permit this air to escape. As a result, the action in closing the door is much smoother and much of the bounce usually experienced at the time the air compresses to a point where the movement of the plunger virtually stops is avoided.
If desired, an embossed by-pass 58 may serve to accelerate the closing of the door B near the end of the door closing period. This by-pass 58 also permits the ing disadvantages.
door B to be opened more readily during the initial portion of its opening swing.
One or more indicating lines 56 are provided on the plunger rod 16, these indicating marks providing an indication of the proper setting of the stop member 57 to provide a proper original tension of the spring. The member 57 is constructed as best illustrated in Figure 3 of the drawing. It includes a flat plate portion 59 having an aperture 6% therethrough which encircles the plunger rod 16. The aperture 60 is somewhat larger than the diameter of the plunger rod 16 so that the plate 59 may tilt somewhat out of a plane normal to the axis of the plunger rod and the edges of the aperture may bind against the plunger rod 16. A substantially right angularly extending arm 61 projects from the plate 59 and is bent downwardly to some extent to engage against the cap 62 through which the plunger rod 16 and which closes the right hand end of the cylinder as indicated in Figure 2. The cap 62, as well as the spring retainer 35, are provided with sufliciently large apertures 53 and 64, respectively, to permit the free flow of the air into the right hand end of the cylinder.
If desired, the indicating lines 56 may comprise notches extending slightly into the surface of the plunger rod so that as the member 57 is tilted, it actually engages into the notch and is definitely held from sliding movement until the cylinder is moved relative to the plunger arm.
The marks 56- are properly spaced to provide varying tension on the spring 43 when the door is closed. For example, three such indicating marks 56 may be provided, one for properly tensioning the spring for extremely lightweight doors, another for tensioning the spring for medium weight doors, and the other for tensioning the spring for heavy doors. Obviously, the heavier the door, the more initial tension is placed upon the spring 43. Thus it will be seen that a simple and effective closer is provided which is extremely effective for its intended purpose and which provides all of the advantages of previous structures without the accompany- The closer moves more effectively than would otherwise be the case, and the use of a spring pre-tensioning clip may be avoided.
In accordance with the patent statutes, I have described the principles of construction and operation of my door closer, and While I have endeavored to set forth the best embodiment thereof, I desire to have it understood that changes may be made within the scope of the following claims without departing from the spirit of my invention.
1. A door cioser including a pair of brackets connected to a door and its frame, respectively, a cylinder connected to one of said brackets, a piston rod extending from one end of the cylinder and connected to the other of said brackets, a piston mounted on said piston d for sliding movement in said cylinder, and a spring within said cylinder for urging said piston into a predetermined position in which the door is closed, said piston being formed with a peripheral groove, an O-ring in said groove, a passageway connecting the base of said groove to the end of the cylinder opposite that from which the piston rod extends, movement of said piston in said cylinder during the closing of the door by said spring acting to compress air in said opposite end of said cylinder, said passage permitting the compressed air to enter said groove to expand said D-ring.
2. A door closer including a pair of brackets connected to a door and its frame, respectively, a cylir er connected to one of said brackets, a piston rod extene from one end of the cylinder and connected to the 0th.. of said brackets, a piston mounted on said piston rod for sliding movement in said cylinder, and a spring within said cylinder for urging said piston into a predetermined position which the door is closed, said piston being formed with a peripheral groove, an Q-ring in said groove, a passageway connecting the base of said groove to the end of the cylinder opposite that from which the piston rod extends, movement of said piston in said cylinder during the closing of the door by said spring acting to compress air in said opposite end of said cylinder, said passage permitting the compressed air to enter said groove to expand said O-ring, a flexible washer engaging said piston in surface contact therewith, and a reinforcing washer in surface contact with said flexible washer, said spring engaging against said reinforcing washer, and said piston also having a small passage leading from the base of the groove to the surface of said flexible washer.
3. The structure described in claim 2 and in which the passage between the base of the groove and said opposite cylinder end is substantially larger than the passage from the base of the groove to the surface of the flexible washer.
References Cited in the file of this patent UNITED STATES PATENTS 289,776 Luton Dec. 4, 1883 1,564,484 Kibele Dec. 8, 1925 2,703,907 Newell Mar. 15, 1955 2,808,608 OHare Oct. 8, 1957