US3408683A

US3408683A - Door closer

Info

Publication number: US3408683A
Application number: US458640A
Authority: US
Inventors: Zahn Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-05-25
Filing date: 1965-05-25
Publication date: 1968-11-05
Anticipated expiration: 1985-11-05
Also published as: GB1103857A; DE1584248A1; NL6506667A; CH457183A; BE664340A; FR1440242A; AT276996B

Description

Nov. 5, 1968 P. ZAHN 3,408,683

DOOR CLOSER Filed May 25, 1965 Sheets-Sheet 1 Inventor: PA 04 ZAH/V yrp /gzs ww Filed May 25, 1965 6 Sheets-Sheet 5 Fig.5

Inventor.- PA 01. ZAH/V Nov. 5, 1968 P. ZAHN 3,408,683

DOOR CLOSER Filed May 25, 1965 6 Sheets-Sheet 4 80 80 80a 80b Eh 1 1 m l\ W, m I as I Inventor:

P. ZAHN DOOR CLOSER Nov. 5, 1968 6 Sheets-Sheet 5 Filed May 25, 1965 D 4 s Q m 3 W u F W W 7 FO/UQ 9 2 v L 6 H M H 9 /6 6 H/ I, 0 \h A lllIllllbl 7 6 H The! M 7 Nov. 5, 1968 P. ZAHN 3,408,683

DOOR CLOSER Filed May 25, 1965 6 Sheets-Sheet 6 I27 I32 I26 725 728 Fig.14

Inventor: PA uz. Z-AHA/ ATTY- United States Patent Filed May 25, 1965, Ser. No. 458,640 Claims priority, application Germany, May 25, 1964, Z 863 20 Claims. (or. 16-51) ABSTRACT OF THE DISCLOSURE A hydraulic door closer is provided including a housing, a piston axially movable in the housing and dividing the interior of the housing into two fluid spaces, and a back-pressure valve, also serving as a throttle valve, incorporated in the piston for the passage therethrough of a fluid and constructed as a disc valve with a resilient valve seat ring fixed to one end face of the disc valve and covering supply and discharge passages provided in the disc valve and terminating in a common axial passage in the disc valve, with the supply passage being constructed as a ball check valve. The door closer is linked to the door frame by a linkage including at least one lever arm hingedly connected between the door closer and the door frame.

This invention relates to a door closer to be incorporated in doors made of steel, wood or any other suitable material, by means of which such doors, on the one hand, can be arrested or locked in one or more open positions and, on the other hand, can be slowly and dampingly closed again, and which has a housing the interior of which is subdivided into two fluid spaces by means of a piston provided with an incorporated back-pressure valve for the passage therethrough of the fluid.

Hydraulic door closers are already known in which the cylindrical interior of the housing is subdivided into two fluid spaces by means of a spring-loaded piston sealed against the cylinder wall. This construction requires accurate axial alignment of the moving parts and of the bearings in order not to further impair the tightness of the dynamic sealing. The lateral forces occurring when opening the door to more than 90 and acting on the piston rod positively require a superimposition of the piston including the piston rod, which has a negative effect on the functioning and efliciency of the door closer. Due to the rate of the closing spring such door closers have a relatively small closing force which in most cases is insuflicient so that additional means are required for holding the door in the closed position, which is to be considered a drawback.

Accordingly, it is the object of the present invention to provide a door closer which, although of simple design, ensures reliable functioning and meets all require ments, avoiding the above-mentioned disadvantages.

To attain this object, the invention provides a door closer of the initially specified type which is characterized in that the back-pressure valve, which simultaneously serves as a throttle valve, is constructed as a disc valve with a resilient valve seat ring.

In a preferred embodiment, the valve seat ring may be fixed to one end face of the disc valve and cover several supply and discharge passages in the disc valve, in which case the supply passage may be constructed as a ball check valve.

Between the valve seat ring and the adjacent end face of the disc valve a groove acting as a throttle gap may be provided which connects the supply passage with a fluid chamber and which provides a by-pass for the fluid. The disc valve may be pressed into an opening in the end face of a plunger piston arranged for axial displacement in the housing and a hose for receiving the fluid and having an open and a closed end may be connected with its open end to the disc valve and arranged to extend longitudinally within the plunger piston. A helical compression spring may be arranged to surround the plunger piston, thereby to subject the plunger piston and the disc valve to a predetermined spring load and to automatically cause axial displacement of the plunger piston together with the disc valve in the closing direction. Within the cylinder of the housing an axially displaceable damping and securing member may be arranged to face the end face of the valve seat ring, which member is subjected to a spring load and longitudinally adjustable by means of a setscrew having a stop pin and/or a toothed adjusting disc. This damping and securing member ensures in an advantageous manner a uniformly damped closing of the door and secures the door in the closed position by exerting a favourable keeping force. The disc valve provided with the hose may be stationarily mounted within the housing, and a spring-loaded plunger piston provided in the region of the valve seat ring opposite the hose may be disposed to be axially displaceable within the housing. Furthermore, the disc valve may be arranged with a piston rod for axial displacement within the cylinder of the housing by means of a helical compression spring, with the helical compression springs, which act on the piston rod and the plunger piston as well as the disc valve, expediently initiating a uniform and damped closing movement of the door.

According to a further feature of the invention, a linkage is hinged to the plunger piston and/ or the piston rod of the disc valve, which enables the door to be opened through an angle of up to or respectively, and to be secured in such position. The linkage may comprise a swinging bar hinged to the door frame and to the door closer, which swinging bar is provided with a locking pawl engaging the leading edge of the door, as Well as a slot at one end thereof which permits the swinging bar to be displaced, for arresting the door. Moreover, the linkage may consist of two hinged levers, the relative pivotal movement of which is limited by means of the locking pawl and a shoulder cooperating with a stop pin.

It is within the scope of the invention to constitute the linkage of several, for example four, lever arms hinged to one another by means of bolts, the range of pivotal movement of the individual lever arms being limited by stop pins and stop faces. This linkage may be advantageously provided with a sectional plastic strip vulcanized thereon which favourably assists the return movement of the linkage from the bent into the straight position and which prevents damage to the inner wall of the piston guide.

The new door closer proposed by the invention has a uniformly damped closing characteristic so that the door incorporating it will fall noiselessly into the door-folding.

Several embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a door in open position which incorporates the door closer according to the invention;

FIG. 2 is a perspective view of the door closer;

FIG. 3 is a longitudinal section through the door closer with the door in open position;

FIG. 4 is a longitudinal section through the door closer with the door in closed position;

FIG. 5 is a longitudinal section through a door closer of a modified embodiment;

FIG. 6 is a longitudinal section through a door closer of another modified embodiment;

FIG. 7 is a perspective view of part of a door with an FIG. 9 is a cross section through part of a closed door with the linkage hinged to the door closer incorporated in the door and to the door frame for opening the door through an angle of up to about 110 with the possibility of arresting the door in such open position;

FIG. 9a is a section through a pair of fish plates of the linkage, taken on the line I,I of FIG. 9;

FIG. 9b is a cross section through part of a door with an incorporated door closer pivotally connected with the linkage, the door being in locked open position;

FIG. 10 is a top plan view of a modified embodiment of the linkage with locking means;

FIG. 10a is a top plan view of another modified embodiment of the linkage with locking means;

FIG. 11 is a top plan view of a further embodiment of the linkage with locking means;

FIG. 12 is a top plan view of a linkage fixed to a door frame and permitting a door to be opened through an angle of about 190;

FIG. 12a is a fractional top plan view of a still further embodiment of the linkage;

FIG. 13 is a top plan view of part of a modified linkage;

FIG. 13a is a perspective view of part of a further modified linkage;

FIG. 14 is a longitudinal section through another modified embodiment, and

FIG. 15 is a longitudinal section through a further modified embodiment.

FIGS. 1 to 4 show a door closer 10 which consists of a tubular housing 11 in one end of which an attachment member 12 is slidably arranged for articulating a linkage 14 which non-positively connects the door closer 10 with a door frame 13. A plunger piston 15 is fixed to this attachment member 12, extends within the housing 11 in the longitudinal direction thereof and is arranged so as to be slidable with the attachment member 12. In the center portion of the housing 11 a packed guide piece 16 for guiding the plunger piston 15 in its to and fro movement is arranged and secured in position by two axially spaced retaining rings 17:: and 17b which are firmly connected with the housing 11 by means of beads or the like provided in the wall of the housing. At its end opposite the attachment member 12 the plunger piston 15 incorporates a valve body 18 which is sealingly forced into the plunger piston 15. A hose 19 closed at one end is connected to the valve body 18 and extends within the plunger piston 15 over the entire length thereof. The hose 19, which is of resilient material, serves to receive a medium, preferably'a liquid, and is circumferentially clamped between the valve body 18 and the inner wall of the plunger piston 15 thus to establish a fluid-tight connection with the valve body 18. The valve body 18 is provided with a central bore 20 in its end face adjacent the hose 19, which bore, on the one hand, communicates with a supply passage 21 which has a reduced diameter at its opposite end, and, on the other hand, with a discharge passage 22. The two passages 21 and 22extend diagonally outwardly and terminate in the edge portion of the front face of the valve body 18. In the supply passage 21 a ball 23 is arranged to close the reduced diameter portion thereof against the opening of which it is urged by a spring 24. The ball 23 advantageously permits a vacuum to be established in the pressure space, as is required for the desired increase of the locking force. The valve body 18 abuts with a flange 18a against a front flange of the plunger piston 15 and is provided with a central pin 25 projecting from its front face and surrounded by a circular valve seat ring 26 covering the remaining annular front face of the plunger piston 15. In the region of the supply passage 21 the front face of the valve body 18 has a groove 27 (FIGS. 3, 4, 7) acting as throttling gap through which p t 4 liquid can flow into the hose 19 through the supply passage'21. In order to prevent clogging of the groove 27, the discharge passage 22 may be arranged near the supply passage 21 in the valve body 18 so that the liquid flows through the groove 27 against the throttling effect and thus the groove 27 is flushed (cf. FIG. 7).

Around the plunger piston 15 a helical compression spring 28 is provided which, on the one hand, is supported by the retaining ring 17a and, on the other hand, presses against the flange 18a of the valve body 18 and tends to axially displace the plunger piston 15.

A sealed closure member 29 is forced into the opening at the end of the housing 11 and provided with an end portion 29a of reduced diameter which extends axially in the housing 11. The closure member 29 has a central setscrew 30 which with a stop pin 31 having a front-end flange 31a projects into a cylindrical central bore 32a formed in a damping and securing member 32 which surrounds the stop pin 31 and serves to brake the door shortly before it abuts on the door frame and to arrest it in its shut position. The member 32 is provided at each of its two ends with a stop ring 33a or 33b, respectively, against either of which stop rings the flange 31a will bear depending on the adjustment of the setscrew 30 and the movement of the plunger piston 15. A helical compression spring 34 surrounding the member 32 as well as the re duced end portion 29a of the closure member 29 bears, on the one hand, against the inner annular face of a radially outwardly extending flange portion of the stop ring 33b and, on the other hand, against a shoulder of the closure member 29 and urges the damping and securing member 32 axially away from the closure member 29 so that the member 32, in the open position of the door, is located with its stop ring 33a behind the flange 31a of the stop pin 31 (see FIG. 4). In the closed position of the door (see FIG. 3), the valve seat ring 26 of the valve body 18 is located in front of the end face of the damping and securing member 32, with the hose 19 being filled with a medium, preferably a liquid, and the arrangement of the valve ring 26 prevents any possibility of such liquid flowing out of the hose 19, since the valve seat ring 26 closes the discharge passage 22 while the supply passage 21 is sealed by the ball 23 acted upon by the fluid pressure and the spring 24. Concurrently, the damping and securing member 32 is urged against the front face of the reduced end portion 29a of the closure member 29 by the valve body 18, thereby to secure the plunger piston 15 and thus the entire door closer in its actual position. In the open position of the door (see FIG. 4), the movement of the door and the force thereby applied to the plunger piston 15 has moved this latter within the housing 11 axially outwardly, whereby a vacuum has been produced in a pressure space 35 formed within the cylindrical housing 11 between the plunger piston 15 and the member 32, such vacuum having caused the valve ring 26 to bend open and clear the discharge passage 22 so that the liquid can flow therethrough. The member 32 likewise has been axially displaced by the spring 34 so as to come with its stop ring 33a to bear against the front-end flange 31a of the stop pin 31.

The aforedescribed door closer operates as follows:

When the door is being opened, it describes a swinging movement which by the linkage 14 is transmitted as a tractive force on the attachment member 12, whereby the plunger piston 15 is axially displaced within the cylindrical housing 11. Such displacement produces a vacuum in the pressure space 35 between the end face of the valve body 18 and of the member 32 which due to its suction effect lifts or bends the valve seat ring 26 off the end face of the valve body 18, whereby the discharge passage 22 is cleared so that the liquid flows out of the hose 19 into the pressure space 35. During the displacement of the plunger piston 15 the spring 28 is compressed to load it for the' return stroke of the plunger piston 15. When the tractive force of the linkage diminishes and, finally,

ceases, the spring 28 tends to restore the plunger piston into its initial position. This reverse movement of the plunger piston 15 is damped by the liquid in the pressure space which urges the valve seat ring 26 tightly against the end face of the valve body 18 and thus closes the discharge passage 22. The liquid under pressure penetrates through the throttle gap 27 the supply passage 21, urges the spring-loaded ball 23 back and flows into the hose 19 to fill same. When the liquid flows into the hose 19, the pressure space 35 is gradually emptied, whereby the plunger piston 15 is axially displaced toward the damping and securing member 32 with the door being slowly closed. To avoid hard and noisy banging of the door, the interpositioned member 32 under the action of the spring 34 damps the force of movement of the plunger piston 15. The plunger piston 15 is urged by the spring 28 towards the closure member 29 until the door is completely closed. During this operation, the two end faces of the valve body 18 with the valve seat ring 26 and of the damping and securing member 32 are in firm contact with each other and the member 32 recedes as its spring 34 is compressed by the stroke of the plunger piston 15 so that the soft closing of the door is ensured. In this psition of the arrangement, the liquid is contained in the hose 19 and prevented from flowing back into the pressure space 35 by the ball 23. The door has attained its rest or closing position. The increased closing action is obtained at the moment when the end face of the valve body 18 with the valve seat ring 26 and the end face of the member 32 bear against each other and thus prevent the discharge passage 22 from being opened, The plunger piston 15 then can move in the closing direction only.

Opening of the door is only possible after overcoming the closing force by the vacuum establishing in the space 35 and the spring 34 acting upon the member 32.

The adjustment of the damping and securing member 32 is effected by means of the setscrew 30 in that the length of the receding path of the member 32 is adjusted. During this adjustment, the member 32 is more or less distant from the closure member 29 and the receding path of the damping and securing member 32 is more or less long, which determines the degree of the damped closing and of the increased closing effect. The stop ring 33a of the member 32 is constantly located behind the flange 31a of the stop pin 31 since the spring 24 constantly urges the member 32 in this direction and thus is more or less loaded due to the position of the flange 31a, which affects the mode of the damped closing action. The adjustment of the setscrew 30 and thus of the damping and securing member 32 can be effected by means of a screw driver. As shown especially in FIGS. 8 and 3, the setscrew 30 may also be associated with a toothed adjusting disc 36 which when being rotated produces the longitudinal movement of the setscrew 30. Providing the adjusting disc 36 is particularly advantageous with relatively wide doors, since in this case a hole 38 can be provided in the upper central region of a door 37, as shown in FIGS. 1 and 8, through which a tool can be applied to the adjusting disc 36 for rotating same. In this case, the adjustment of the setscrew 30 is not effected, as usual, in the longitudinal direction of the door closer 10 but transversely of the longitudinal axis thereof, which results simpler and easier with wide doors.

FIG. 5 shows a modified embodiment of the invention, in which a door closer 40 comprises a tubular housing 41 accommodating a rigidly arranged valve body 42 and a hose 43 for receiving a medium, preferably a liquid.

The hose 43 has an open end sealingly connected with the valve body 42 and a closed end extending away from the valve body 42 towards one end of the housing 41. From the ground of a central drill hole 44 in the end face of the valve body 42 a passage 45 extends at an inclination outwardly. A central stud 42a projecting from the end face of the valve body 42 remote from the hose 43 is surrounded by a valve seat ring 49 of resilient material which closes the passage 45 outwardly. In the regio: of the passage 45 a groove 50 is provided which acts a a throttle gap and permits the liquid to flow from a pres sure space 51 through the passage 45 into the hose 43.

A plunger piston having a piston end flange 55t directed towards the studded end face of the valve bod 42 is sealed in the housing 41 by a gland 54, which i: secured in place by a retaining ring 53 and guided f0] sliding longitudinal movement within the housing 41 b a collar 52. The plunger piston 55 is loaded by a helical compression spring 56 which bears against the collar 52 and exerts a pressure on the annular inner end face of the piston flange 55a. A linkage (not shown) is secured to the door frame and hinged to the plunger piston 55. In the closed position of the door, the hose 43 is filled with the medium. When the door is being opened, the plunger piston 55 is subjected to a tractive force through the intermediary of the linkage and axially displaced away from the valve body 42, whereby a vacuum is produced in the pressure space 51, which results in the valve seat ring 49 being bent away from the opening of the passage 45 so that the liquid can flow from the hose 43 into the pressure space 51. The pressure space 51 thus is filled with the medium and assists the rearward movement of the plunger piston 55, whereby the spring 56 is compressed for the subsequent closing of the door. The door then is in its open position.

When the plunger piston 55 is no longer subjected to the tractive force and the flow of the medium has ceased, the pressure which has been built up in the pressure space 51 acts on the valve ring 49 to press same against the end face of the valve body 42 and close the passage 45 same for the groove 50. Now the medium flows between the valve ring 49 and the end face of the valve body 42 into the groove 50 and returns through the passage 45 into the hose 43. During this flow, the spring 56 moves the plunger piston 55 with its end flange 55a towards the valve body 42 and the door is slowly and softly closed.

In a further embodiment, which is illustrated in FIG. 6, a door closer 60 comprises a tubular housing 61 accommodating a displaceable sealed valve body 62 and a piston rod 63 which is non-positively connected with the valve body 62. The piston rod 63 is arranged to slide in a guide ring 66 secured in place by retaining rings 64 and 65. Between the guide ring 66 and the end face of the valve body 62 a space 67 for a medium, preferably a liquid, is defined which when the valve body 62 is displaced is enlarged or reduced according to the direction of movement of the valve body 62. The piston rod 63 is surrounded by a helical compression spring 68 which bears against the retaining ring 64 and exerts a pressure on the valve body 62 so as to keep the extension of a liquid chamber 76 as small as possible and thus to bring about the closing movement of the door. The piston rod I 63 engaging in the valve body 62 has a passage 69 which comprises a portion opening into the space 67 and extending at right angles to the axis of the door closer 60 from the peripheral surface of the piston rod 63 to the central axis thereof and an adjoining portion extending coaxially with this central axis and opening into a central drill hole 70 in the valve body 62. A supply passage 71 and a discharge passage 72 extend from the central drill hole 70 to the end face of the valve body 62 facing the liquid chamber 76. The supply passage 71 in its length portion adjacent the drill hole 70 accommodates a springloaded ball 73 which closes an adjoining reduced portion thereof.

From the end face of the valve body 62 facing the liquid chamber 76 a central stud 62a projects which is surrounded by a valve seat ring 74 of resilient material covering the opening of the reduced portion of the supply passage 71 and the opening of the discharge passage 72. In the region of the opening of the supply passage 71 a groove 75 is provided between the valve seat ring; 74 and the adjacent end face of the valve "body 62 which 7". lCtS as a throttle; gap. -Through thegroove 75 liquid :an penetrate from the liquid chamber 76 into thesup- )ly passage 71 and hence -fiow through'the passage 69 nto the space 67, whereby the closing of thedoor is ichievedJ- Inthe closed position-of the *door, the valve body 52 is spaced a predetermined distance apartfrom the retaining ring 64 and'the intermediate space -67 is relatively large, whereas the liquid chamber 76 is relativel'y' smallr'lf the-piston rod- 63 is subjected to. pull, it is axially displaced towards the retaining ring 64, which resultsin a reduction of the' space 67 and thus in a higher pressure" of the liquid contained therein. Consequently, the liquid penetrates the passage 69 and flows through the discharge'passage 72, from which the'valve seat ring 74 is lifted off, into the liquid chamber 76. When the piston rod 63 and the valve body" 62 are pushed back, the door'is opened and'the'spring 68 compressed. i i

Closing of the -door is brought about by the spring 68 in that it urges the val've'body 62 back. Simultaneously', liquid from the liquid chamber 76 flows through the groove 75 into the'supply passage 71, pushes theball 73 against the action of its spring off its seat to clear the passage 71 and flows on through thepassage 69 into the space 67. The space 67 is again filled with liquid and the door slowly closes.

The door closer proposed by the invention is suitably provided with a valve body having a valve seat ring which enables the valve body to act as a throttle, check and by-pass valve. Such valve seat' ring is expediently arranged on the end face of the valve body to regulate by the movement of the valve body the rate and volume of flow. A door closer of this kind ensures a uniform and invariably constant closing movement of the door from the beginning (widest open position) of the movement to the termination (closed position) thereof,with such movement being slightly damped. The door snaps noiselessly into the door fold, whereas an increased closing force becomes active as described with reference to FIGS. 3 and 4.

The door closer proposed by the invention has the advantage that the door when being closed falls noiselessly into the door fold, that the door is subject to an increased closing effect, and that the door can be easily and rapidly opened.

Such a door closer can be incorporated in the upper and/or lower portion of the door, i.e. in a steel door or the like it can be incorporated in the upper portion thereof and in a wooden door in the lower portion thereof.

FIGS. 9 to 11 show a linkage for the non-positive connection of a door closer incorporated in a door to the door frame and for arresting the door is a selected open position.

In FIGS. 9 to 9b the linkage is shown to comprise a swinging bar 80 formed of two fish plates 80a, 80b and an intermediate member 800. At one of its ends the swinging bar 80 is hinged by a bolt 83 to an eyebolt 82 secured to a "door frame 81. The other end of the swinging bar 80 is provided with an oblique slot 84 engaged by a bolt 85. The bolt 85 is displaceable in the slot 84 and connects the swinging bar 80 with a guide member 86 of the piston rod and/ or the plunger piston of a door closer 88 incorporated in a door 87. In the central portion of the swinging bar 80 a locking pawl 89 is rigidly arranged on one side thereof. When the door 87 is swung open about hinge pins 90, the guide member 86 with the connected piston rod and/or plunger piston of the door closer is pulled outwardly, i.e. in the direction of the hinge pins 90, and the closing spring within the door closer is loaded for the subsequent closing action.

During the opening of the door 87 the swinging bar 80 moves almost completely out of the door 87 (cf. FIGS. 9 and 9b) If, for example, the door 87 is to be arrested at an opening angle of 95 -for through traffic, itis opened to about 150 and then pulled back with a short jerk. By the damping. effect of the door closer 88 in the closingdirection transverse forces acting'towards the door closer'88 are produced in the slot 84in the swinging bar 80, whereby the swinging bar is forced laterally out of the central axis due to the obliquity of the slot 84- (cf. FIG: 9b) and the locking pawl 89, at the same time, is brought in front of the leading edge of. the "door 87 or that of the door closer 88, respectively, thereby to lock the door 87 against further movementin' the closing'direction. By the lateral displacement of the swinging bar 80 out of' its central axis 'a dead centre position is attained which, assisted by the locking pawl 89, causes the door 87 to be arrested. The locking pawl 89 serves to arrest-the door 87 and to lock it in' its position until a t'ractive force produced by the further opening of the door 87 pulls the swinging bar 80 in the s1ot84again in the central axis, whereby the closing movement of the door 87 is initiated.

FIG. 10 shows a linkage, in which an eyebolt 91-to be secured to a door "frame (not shown) is hingedly connected with one of the ends of a swinging bar 93 by means of a bolt 92. The opposite end of the swinging bar 93 has out of its longitudinal central axis a pivot 94 for a lever 95 which at its end opposite the pivot 94 is rotatably mounted on a door-96 by means of a bolt 97. In the region of the pivot 94, the swinging bar 93 is formed on one side with a locking pawl 98 'and the lever 95 is provided with a shoulder 99 contacting a stop pin 100 provided on the swinging bar 93 out of the central axis thereof. During the opening movement of the door 96, the lever 95 and the swinging bar 93 are on the same longitudinal axis and the shoulder 99 is in contact with, and arrested by, the stop pin 100. If the door 96 is to be locked in its opening movement, it is pushed in the direction of the swinging bar 93 so that the lever 95 and the swinging bar 93 are rotated relative to each other about the pivot 94 until the locking pawl 98 engages the leading edge of the door 96. In this position, which is represented in FIG. 10a, the door wing 96 is locked in its open position in which it will remain until the door closer is subjected to a tractive force which acts to bring the swinging bar 93 and the lever 95 from their dead centre positions back into the initial positions in which their central axes coincide with the same longitudinal axis.

FIG. 11 'shows a modification of the aforedescribed linkage. This modified linkage comprises a swinging'b'ar 101 and a lever 102 which are connected to cooperate in the same manner as the swinging bar 93 and the lever 95 shown in FIGS. .10 and 10a. The modification consists in that the lever 102 is formed integral with a shoulder 103 and a locking pawl 104. The mode of operation of this linkage corresponds to that of the linkage shown in FIGS. 10 and 10a.

The linkages described with reference to FIGS. 9 to 11 permit a door to be opened to an angle of about and to be locked in different angular positions.

FIGS. 12 to 13a show two embodiments of a linkage for connecting a door closer incorporated in a door witha door frame in a manner permitting an opening angle of up to 190.

The linkage shown in FIG. 12 comprises four

lever arms

110, 111, 112 and 113, with the lever arms 1.10 and 112 being arranged as forked double-levers.

The hinge joints between the lever arms 110 to 113 and between the lever arm 110 and an eyebolt 115 secured to. a door frame 114 are provided by means of bolts 116. The

lever arms

111 and 113 are each provided at one of their ends with a stop pin 117 laterally displaced from their longitudinal central axes and the lever arm 111 has a second stop pin 118 at its other end, which is arranged parallel to its stop pin 117, whereas the lever arm 110 is provided with a stop pin 119 the reference numeral 120, of the

lever arms

110, 111 and z The spacing of the pivot points of the individual lever arms, which are constituted by the bolts 116, increases at a predetermined rate from the door frame 114 towards the door closer. This causes a shape of the lines of force which is in the curve of a parabola when the door is opened up to an angle of 180, all occurring forces being axially transmitted to the central axis of the door closer. The stop pins 117, 118 and 119 are disposed so that the

individual lever arms

110, 111, 112 and 113 can swing out only to a predetermined angle. The end faces 120 of the

lever arms

110 and 112 extend at right angles to the central axis thereof and the end face 120 of the lever arm 111 extends at an inclination to the central axis, wherebythe pivotal movement of the individual lever arms is limited to a predetermined amount.

The lever arm 113 is provided-with a connection bore 121 for hinging it to the door closer (not shown). The connection to the door closer, however, is effected in the same general manner as shown in FIG. 9, with the difference, of course, that the linkage shown in FIG. 12 allows the door to open to an angle of 190", whereas the linkage shown in FIG. 9 only allows the door to open to an angle of 110.

In the modification shown in FIG. 12a, the end faces of the lever anms 110 and 112 which cooperate with the stop pins 117 and 118 are of concave configuration and provided with lateral limiting lugs 122 'which securely prevent the

lever arms

110 and 112 from pivoting past the limit stops.

The modified linkage shown in FIGS. 13 and 13a corresponds in design and operation to the linkage of FIGS. 12 and 12a. The modification consists in that the

lever arms

110, 111, 112 and 113 are in the form of blanked out U-sections on their external side with a T-section strip 123 of abrasive-resistant resilient plastic.

The strip 123 has the function to assist the return movement of the linkage from the bent into the straight position and to absorb part of the bending forces. Moreover, the strip 123 ensures a noiseless sliding of the linkage within the guide portion of the door closer, when the door is pushed back by force against the damping action of the door closer, with the lever arms being forced to bear on the inner wall of the door closer.

The aforedescribed linkages provide an advantageous connection betwen the door closer incorporated in the door and the door frame in that, on the one hand, a favorable and relative wide opening movement of the door and, on the other hand, a suitable and secure locking of the door in different open positions can be attained.

It falls within the scope of the present invention to arrange the valve ring 26 (FIGS. 3 and 4), 49 (FIG. or 74 (FIG. 6), respectively, also with preloading. Such preloading has the advantage that upon termination of the liquid flow in either direction the valve passages are immediately closed so that the throttling effect is precisely brought into action.

Such arrangement is illustrated in FIG. 14, in which a plunger piston 124 is provided with a spring 125 and with a valve passage 126 serving as a connecting conduit between a pressure space 127 and a closed hose 128. The valve passage 126 is closed by a valve seat ring 129 which is bent and secured in an annular groove 130 in a central stud 131 and thus preloaded against a valve seat 132.

FIG. shows a modified embodiment of a door closer with increased looking action which, on the one hand, serves to protect the fixing and connecting members against overloading, e.g. when the door is pushed shut by force, and, on the other hand, to increase the efliciency in the last section (the last millimetre) of the stroke.

This construction corresponds substantially to that of FIGS. 3 and 4, with identical parts being designatedby the same reference numerals.

In this embodiment, the modification over the construction illustrated in FIGS. 3 and 4 consists in that ,a valve seat ring 135 is preloaded like the one shown in FIG. 14. To this end, a bushing 137 is inserted in a central bore 136 in the funnel-shaped end face of the valve body 18 and provided at its outer free end with a flange 137a centering the valve seat ring 135 and forming a safety valve together with aball 138 urged into the closing position by a spring. A radial passage 139 connects the central bore 136 with the pressure space 35 and crosses a passage 140 between the ball 23 and the seat of the valve seat ring 135.

The dampening and securing member 32 has in its leading end face a recess 142 corresponding to the flange 137a of the bushing 137. The ground of the recess142 is formed with a central projection 141 which upon en gagement with the ball 138 pushes the same off its valve seat at the flanged end of the bushing 137 so that the safety valve is immediately opened and any throttling effect eliminated.

Such a safety valve has the advantage, among others, of securely closing even heavily moving doors. r

I claim:

1. A door closer comprising a housing, a piston axially movable in said housing and dividing the interior of the same into two fluid spaces and a combined back-pressure and throttle valve incorporated in the piston for the passage therethrough of a fluid, said valve being constructed as a disc valve with a resilient valve ring fixed to one end face of the disc valve and covering supply and discharge passages provided in the disc valve which terminate in a common axial passage in the disc valve, the supply passage being constructed as a check valve.

2. A door closer according to claim 1, wherein a groove acting acting as a throttle gap is provided between the valve ring and the adjacent end face of the disc valve, said groove connecting the supply passage with one of the fluid spaces and said disc valve being pressed into an opening in the end face of a plunger piston arranged for axial displacement in the housing.

3. A door closer according to claim 2, wherein a hose for receiving the fluid and closed at one end is connected to the disc valve on the side opposite the valve ring and arranged to extend within the plunger piston, and a helical compression spring is provided which surrounds the plunger piston, subjects the plunger piston and the disc valve to a predetermined spring load and bears, on the one hand, against supporting means for the plunger piston and, on the other hand, against the disc valve.

4. A door closer according to claim 1, wherein a damping and securing member is axially displaceably arranged within the housing to face the valve ring, is adjustable in the longitudinal direction of the housing by means of an axially extending setscrew having a stop pin, and is spring-loaded in the longitudinal direction by a helical compresslon spring.

5. A door closer according to claim 4, wherein a toothed adjusting disc for adjusting the damping and securing member is associated with the setscrew externally of the housing.

6. A door closer according to claim 1, wherein the disc valve provided with a hose is stationarily mounted within the housing and a piston rod is provided in the region of the valve ring opposite the hose and mounted for axial displacement within the housing by means of a helical compression spring.

7. A door closer according to claim 1, wherein the disc valve is mounted for axial displacement within the housing together with a piston rod engaging in the disc valve opposite the valve ring and a helical compression spring Surrounds the piston rod and is arranged between the support of the piston rod and the disc valve, the piston rod being axially displaceable by means of said helical compression spring and provided with a passage extending at right angles and terminating in a common outlet bore of supply and discharge passages provided in the disc valve.

8. A door closer according to claim 1, wherein a link age hingeable by means of pivot elements is arranged on the plunger piston.

9. A door closer according to claim 1, comprising a linkage for, connecting the door closer incorporated in a door to a door frame, said linkage consisting of a swinging bar hingedly connected to the door closer as well as to the door frame and having an elongated hole engaged by a pin on the door closer and provided at one end of the swinging bar so as to extend obliquely to the longitudinal central axis thereof.

10. A door closer according to claim 9, wherein a locking pawl is provided on one side of the swinging bar, said locking pawl being adapted to engage the leading edge of the opened door for locking same in this position and said swinging bar being hinged to a lever.

11. A door closer according to claim 10, wherein the swinging bar is provided with a locking pawl arranged on one side thereof and with a stop pin disposed out of the longitudinal central axis thereof and the lever is provided with a shoulder arranged to engage the stop pin on the Swinging bar.

12. A door closer according to claim 10, wherein the lever is provided with a locking pawl and a shoulder in the region of its pivot point.

13. A door closer according to claim 1, comprising a linkage for connecting the door closer to a door frame, said linkage consisting of several lever arms which are hinged to one another by means of bolts and of which at least two lever arms are forked.

14. A door closer according to claim 13, wherein at least two lever arms are provided with stop pins limiting the range of pivotal movement of the adjacent lever arms 12.a"., and arranged out of the longitudinal central axis of the lever arms.

15. A door closer according to claim 13, wherein the end faces of the lever arms are provided with spaced stop projections engageable with said stop pins, said projections extending generally in the direction of' the 'longitudinal axis of the lever arms.

16. A door closer according to claim 13, wherein a sectional plastic strip is attached to the external side of the individual lever arms, which absorb the bending forces and assist the return movement of the lever arms from their bent position into their straight position.

17. A door closer according to claim 1, wherein the resilient valve ring provided on the disc valve is preloaded.

18. A door closer according to claim 1, wherein the surface on the disc valve providing a ring for the valve seat ring is inwardly inclined.

19. A door closer according to claim 1, wherein the. valve ring is fixed in an annular groove in a central re tai'ning stud projecting from the disc valve. w

20. A door closer according to claim 19, wherein th retaining stud of the disc valve is coustructedcas a ball check valve, cooperating with a projection on a damping and securing member.

References Cited UNITED STATES PATENTS 1,457,122 5/1923 Ree 188-88 2,596,676 5/ 1952 Goderez 16-52 3,025,558 3/1962 Hawks 16-51 3,057,004 10/1962 Sogoian 16-52 3,110,924 1l/l963 Wartian 1652 1,962,291 6/1934 Anderson 1663 X 3,143,757 8/1964 Quinn 16-52 X 3,161,908 12/1964 Walach 16-52 FOREIGN PATENTS 482,440 1 1/ 1951 Italy.

BOBBY R. GAY, Primary Examiner.