US3518715A

US3518715A - Automatic hinge-mounted door closer

Info

Publication number: US3518715A
Application number: US700061A
Authority: US
Inventors: Michael M Weiner
Original assignee: MICHAEL M WEINER
Current assignee: MICHAEL M WEINER
Priority date: 1968-01-24
Filing date: 1968-01-24
Publication date: 1970-07-07
Anticipated expiration: 1987-07-07

Description

July 7, 1970 wE|NER 3,518,715

AUTOMATIC HINGE-MOUNTED DOOR CLOSER Filed Jan. 24, 1968 4 2 Sheets-Sheet 1 M/CHDEL M. WE/NEQ 5L L INVENTOR.

MWZM p Q SEY United States Patent 0 3,518,715 AUTOMATIC HINGE-MOUNTED DOOR CLOSER Michael M. Weiner, Los Angeles, Calif. (P.0. Box 36, Woodland Hills. Calif. 913-64) Filed Jan. 24, 1968, Ser. No. 700,061

Int. Cl. 7505f 1/08 US. Cl. 16--80 l2 Germs ABSTRACT OF THE DISCLOSURE An automatic door closer mountable directly on a door hinge by means of the door hinge pin only. A stationary arm abuts against the door frame. A rotatable arm abuts against the door and pivots with the door about the pivotal axis of the door hinge, i.e., the hinge pm axis. A spring is interconnected between the stationary and rotatable arms in a substantially constant torque arrangement whereby a constant restoring torque is applied by the spring about the hinge pin for closing the door after opening thereof. A latch is provided for deactivating the device. Geometrical, trigonometrical and mathematical relationships and design parameters are disclosed.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to an automatic closing device for a hinge-mounted door and, more particularly, to such a device for mounting directly on the hinge solely via the hinge pin, exerting a substantially constant reactive force against door opening forces, and providing a substantially constant restoring force for closing the door automatically and completely without slamming.

Description of the prior art Although a number of automatic door closing mechanisms exist in the prior art, such mechanisms are usually bulky and complicated devices primarily intended for installation on heavy external doors. Their installation on doors connecting interior rooms would involve considerable expense, difliculty in installation and permanent marring of the door and door frame surfaces during installation and use. Furthermore, their conspicuousness would seriously detract from the normal interior decor.

Some devices of the prior art employ either extension, compression or torsion springs which are conventional in operation during the door opening operation to generate restoring forces. Due to the fact that Hooks law dictates the result in such devices that the restoring torque is linearly proportional to the door opening angle, such devices sulfer from the disadvantages of excessive or slamming force exerted on the door if opened fully and yet insufficiently slight restoring torque if the door is opened slightly. In an attempt to overcome these disadvantages, pneumatic cylinder-piston damping mechanisms have been employed in conjunction with such springs so that higher spring forces can be used. However, due to the normal necessity of a bleeder port in the cylinder, such combinations are still dependent on the speed and extent of the door opening action, are somewhat critical in adjustment and maintenance, are expensive and bulky, require permanent installation albeit removable for repairs, and still often do not provide sufficient restoring forces for closing the door completely to overcome the resistance of the door knob mechanism when the door has been opened only slightly.

SUMMARY OF THE INVENTION According to the present invention, the foregoing probice lems of the prior art mechanisms have been eliminated by providing a simple but effective automatic door closer device which employs an arrangement comprising a substantially constant force spring having one end immobilized relative to the stationary door frame and the other end immobilized relative to the movable door whereby the spring arrangement exerts a substantially constant restoring torque at substantially all degrees of door opening action but provides a relatively high restoring torque at initial or small degrees of door opening angles suflicient to overcome the resistance of the door knob mechanism and effect smooth door closure with little or no slamming action. Further, the respective spring ends are mounted on a pair of arms which respectively abut against the door frame and the door, such arms being mounted on the door hinge solely by means of the door hinge pin, thus eliminating any marring of the door and door frame surfaces while achieving ease of installation and removal. Still further, the arrangement of the spring and arms is such as to create a moment arm which varies slightly in magnitude oppositely to the slight variations in spring force over the practical range of door opening angles whereby the restoring torque (the product of the moment arm and the spring force) is effectively constant over such range. Additionally, a latch is provided for selective manual deactivation of the device whenever desired, without disabling or otherwise interfering with either the door or the mounting of the device.

Accordingly, it is an object of the present invention to provide a novel device for automatically closing a door.

Another object of the present invention is to provide an automatic door closer which is easy to install and remove without marring of the door and door frame surfaces.

Another object of the present invention is to provide a hinge-mounted door with an automatic door closer which is operatively mounted on the door hinge solely by means of the door hinge pin.

A further object of the present invention is the provision of an automatic door closer which applies a substantially constant door closing torque over a wide range of door opening angles.

A further object of the present invention is the provision of an automatic door closer which applies a substantially constant but low torque for closing the door over a wide range of door opening angles and also applies a relatively increased closing torque for very small door opening angles for overcoming the resistance of the door knob mechanism.

A further object of the present invention is the provision of an automatic door closer with a simple latch means to disconnect the device from use without physically removing it or interfering with normal door functrons.

Still further objects of the present invention include the provision of an automatic door closer which is simple and inexpensive to manufacture, small in size and inconspicuous in location, readily installed and removed without requiring the exercise of skill or the use of tools, readily installed on a wide range of different types of doors, reliable in use, requires little or no maintenance or repair, readily packaged and marketed, and attractive 1n appearance.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description of a preferred embodiment, taken in connection with the accompanying drawings.

3 BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a reduced size perspective view of a hingemounted door closer in accordance with the present invention, shown mounted on a door hinge in operative association with a door and door frame;

FIG. 2 is a fragmentary elevational view thereof taken substantially along line 2-2 in FIG. 1;

FIG. 3 is a top plan view thereof with the aspect taken along line 33 in FIG. 1, with the door in a closed position;

FIG. 4 is a top plan view thereof with the door in an open position;

FIG. 5 is an elevational view thereof in the closed door position, with the spring being broken away for clarity of illustration of the other elements;

FIG. 6 is an exploded perspective view, similar in aspect to FIG. 1, showing the stationary and rotatable arms, the pin for mounting a spring end to the stationary arm, and the latch;

FIG. 7 is an enlarged sectional view taken substantially along line 7-7 in FIG. 5, with the door hinge pin shown in broken lines; and

FIG. 8 is a graph illustrating the restoring torque characteristics of the illustrated device.

DESCRIPTION OF A PREFERRED EMBODIMENT It should be noted that FIGS. 3-5 inclusive are full scale drawings of a preferred embodiment of the present invention having optimum performance characteristics. As should be clear, however, the structural dimensions, proportional relationships, and spacings between structural and functional points which vary due to relative motion therebetween may be varied without departing from the inventive concepts disclosed herein and particularly to accommodate differing environmental parameters from those disclosed herein in connection with the particular interior household door application for which the disclosed preferred embodiment has particular and novel utility.

Referring to the drawings, and particularly to FIGS. 1 and 2 initially, there is seen an automatic hinge-mounted door closer 10 in accordance with the present invention mounted on a conventional door hinge 12, the

plates

14 and 16 of which are conventionally secured to a doorjamb 18 of a wall 19 and a door 20. The door closer 10 is seen to comprise generally first and

second arm members

22 and 24, one end or portion of each of which is mounted on the door hinge 12 in pivotal relationship to each other via door hinge pin 26. A spring 28 is secured at its opposite ends to the

respective arm members

22 and 24. A latch 30 is mounted on arm member 22.

Arm members

22 and 24 are provided with respective

resilient pads

32 and 34 for abutment against the door and conventional door frame molding 36, respectively.

Referring more particularly now to FIGS. 3-7, it is seen that

arm members

22 and 24 are each of unitary construction and may be cast or formed to integrally provide a plurality of strengthening ribs along their lengths, such as are indicated at 38 and 40, respectively. Arm member 22 is integrally provided with a pair of vertically aligned spaced

collars

42 and 44 defining a horizontal slot 46 therebetween for freely receiving an end 48 of spring 28 therein.

Collars

42 and 44 are provided with a common vertical hole 50 therethrough for receiving a pin 52 therein, the pin 52 having an enlarged head 54 to prevent the pin 52 from dropping through the hole 50. The spring end 48 is looped about the pin 52 so that the spring end 48 is removably captured by pin 52 and may pivot thereabout. The free end of arm member 22 is provided with a fiat vertical surface 56 upon which resilient pad 32 is secured, as by glue or adhesive, it being understood that

pads

32 and 34 of the device are provided merely for the purpose of preventing marring or scratching of the surfaces against which they rest and 4 may be composed of neoprene, felt or similar suitable materials.

The adjacent ends, indicated generally at 58 and 60, of

arm members

22 and 24, respectively, are integrally provided with

respective sleeves

62 and 64 which receive a bushing 66 common therethrough, preferably with a washer 68 between the

sleeves

62 and 64 to assure relative rotation freely therebetween. Bushing 66 preferably is crimped or upset at its

opposite ends

70 and 72 to retain the

sleeves

62 and 64 thereon in a unitary manner. Bushing 66 is adapted to receive the door hinge pin 26 therethrough, with its enlarged head 74 resting on the bushing end 70. It may be noted that the clearances between the various elements particularly shown in FIG. 7 are not critical, it being desirable merely that hinge pin 26 can be freely slipped through bushing 66 and that sleeve 62 may be freely rotatable relative to sleeve 64. Thus, a journal relationship between the bushing 66 and sleeve 62 of arm member 22 is sufficient to assure such function. It also should be noted that the structural couplings illustrated in FIG. 7 constitute the sole structural support for the inventive automatic door closer device illustrated here- The stationary arm member 24 has a substantially V-shaped configuration to form an elbow region, indicated generally at 76, integrally provided with a collar 78 having a vertical hole 80 therein for loosely receiving a pin 82 therethrough. The pin 82 (best seen in FIGS. 5 and 6) has an enlarged head 84 for ease in manual gripping during assembly and disassembly of the device and is preferably provided with a pair of vertically spaced

annular projections

86 and 88 which define an annular slot 90 therebetween for loosely receiving the other end 92 of the spring 28. The spring end 92 is looped about and thus captured by the pin 82. As in the case of the spring end 48, spring end 92 may be merely free to pivotally rotate about the longitudinal axis of its capturing pin 82 and, thus, if pin 82 is freely rotatable within its collar 78, spring end 92 may be either tight or loose about pin 82.

Referring now more particularly to FIGS. 3 and 4, it is seen that the spring 28, in and of itself, is a conventional coil spring having a plurality of identical coil portions which, in their substantially relaxed state as indicated at 28 in FIG. 3, form an effectively cylindrical configuration in gross. Spring ends 48 and 92 are formed from continuous extensions of the coils 28 at the ends of the cylinder via respective end portions and 102. It should be noted that an imaginary line, indicated at 103, drawn between the axes of rotation of spring ends 48 and 92, i.e., the longitudinal axes of pins 52. and 82, respectively, falls outside the effectively cylindrical exterior of the body of the spring 28.

As seen in FIG. 4, opening of the door 20 causes rotatable arm 22 to pivotally rotate about the vertical axis, indicated at 104, of the door hinge pin 26 so that the vertical axis, indicated at 106, of pin 52 describes an are about hinge pin axis 104, thus bringing spring end 52 closer to spring end 92 which, as previously mentioned, has the pivotal axis indicated at 108 which is the longitudinal axis of pin 82 and is spaced from hinge pin axis 104. The spring 28 is deflected into a curved arc, FIG. 4 illustrating the spring 28 in a fully deflected position after the door 20, and, accordingly, rotating arm member 22 have been rotated to an angle of 100.

At the position shown in FIG. 4, the latch 30 can be secured about pin 82, preferably at the exposed shank portion 110 (see FIGS. 5 and 6) whereby the

arms

22 and 24 are locked together. Note the simplicity of latch 30, which is merely fastened to rotating arm member 22 at 112 as by a machine screw so that the hooked end 114 is firmly held in locking engagement with the pin 82 by virtue of the restoring force of the spring 28 which otherwise would cause removal of arm member 22 from its position adjacent the pin 82. It should be noted that rotating arm member 22 is not attached or in any manner secured to door 20, so that the door 20 is free to rotate about its hinge pin 26 without interference from the thus-latched device all the way from the closed door position of FIG. 3 to the 100 open position of FIG. 4.

As now should be clear, if the latch 30 is not engaged as above described, the spring 28 exerts a force on the rotating arm member 22 which, in turn, exerts a restoring torque on the door 20 forcing the door to close and return to the position shown in FIG. 3. The restoring torque provided by the device is the product of the force exerted by the spring 28, which acts along the line 103 joining the axes or centers of the restraining pins 52 and 82, and a moment arm which is the distance from the axis 104 of the hinge pin 2.6 to the line 103 of force. FIG. 8 is a graph illustrating the foregoing relationships in a qualitative manner. Thus, curve 120 shows the variations in the above-described moment arm with a door opening angle varying from closed to the open position of FIG. 4 (100), curve 122 shows the varying force of spring 28 exerted along the line 103 of force, and curve 124 is a plot of the products of the respective distances and forces of

curves

120 and 122 for the various door opening angles; thus, curve 124 is a plot of the restoring torque exerted by the above-described automatic door closer 10. It should be noted that the restoring torque is revealed by curve 124 to be nearly uniform for a wide range (indicated at 126) of door opening angles, approximately 10 to 70. Importantly, it should also be noted that a rapid, though not excessive, rise in the restoring torque is obtained at very small door opening angles of 0 to about 5 (indicated at 128), thus achieving the highly advantageous effect of firm door closing without excessive slamming action.

It now should be clear that the performance characteristics of any particular device made in accordance with the present invention are dependent only on the particular values chosen for the parametric lengths of

arms

22 and 24 and the angle included therebetween, assuming predetermined values and dimensions of the spring 28. Accordingly, the following discussion refers to FIGS. 3 and 4 for clarity and will establish the appropriate criteria and relationships therefor so that the performance under static conditions (torque vs. opening angle) illustrated in FIG. 8 can be calculated.

The static torque exerted by the device is experienced equally by

arms

22 and 24, although in opposite directions, and can be expressed in terms of the effective lengths of the

arms

22 and 24, the angle included there between, and the force exerted by spring 28. The effective length of arm 22 is the distance between

points

104 and 106, which arm length will be referred to herein as L similarly, the effective length of arm 24 is the distance between

points

104 and 108, referred to herein as L The included angle between the effective geometrical arms L and L will be referred to as Y. The force exerted by the spring 28 along its line of action 103 will be referred to as P, and the length of line 103 between

points

106 and 108 will be referred to as L The static torque T is the product of the force P exerted by the spring 28 and a moment arm equal to the perpendicular distance from point 104 to the line 103. From trigonometry, it follows that the torue T and length of line L are given by the following expressions:

The force P exerted by the spring is dependent on the spring design. For the particular optimum spring 28 illustrated, the force P and spring deflection S (the increment of change in length of line L are calculated by the following expressions:

P=applied force (1b.)

d=wire diameter (in.) Dzmean coil diameter (in.) S =spring deflection (in.) P initial tension (1b.)

Rzarm angle (degrees) N=number of active coils 28' Q=spring body angle (radians) G=torsional modulus (p.s.i.) A=arm length (in.)

The arm length A is the effective length of the spring end portion or 102 and is measured between the extremus of the last active coil 28 and the springs

adjacent pivot point

106 or 108. The arm angle R relates to the angular relationship of the spring body and its connecting end portions to the pivot points 106 and 108, and constitutes the acute angle included between two lines drawn in the closed door position of FIG. 3, one of which lines is an extension of an axial line tangent to the mean coil periphery, the other of which lines is from the

adjacent pivot point

106 or 108 to the closest point of the last active coil 28'. It should be noted that the spring force P is not given explicitly in terms of the deflection S but that both force P and deflection S are given in terms of another parameter called the body angle Q which, viewing FIG. 4, is the acute angle included between a line transversely bisecting the spring 28 and, therefore, normal to a line 103 between pivot points 106 ad 108, and a line through one of the pivot points 106 or 108 and lying in the mean plane of the opposite (most remote) active coil 28.

The optimum values for the parameters of the short arm L the long arm L and the angle Y included therebetween have been computed and have resulted in the full scale configuration illustrated. However, the foregoing disclosure will enable anyone having ordinary skill in the art to modify any and all of the parametric values to achieve desired performance characteristics under the same or different environmental conditions of any particular application.

While particular embodiments of the present invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspects, and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

I claim: 1. An automatic door closer adapted for mounting on the conventional hinge of a door via the hinge pin only and adjacent the door frame, comprising:

stationary arm means having a first portion mountable on the door hinge via the door hinge pin and a second portion adapted to abut against the door frame;

rotatable arm means having a first portion pivotally mountable on the door hinge via the door hinge pin and a second portion adapted to abut against the door whereby opening rotation of the door about its hinge pin will cause pivotal rotation of said rotatable arm means about the door hinge pin;

spring means having first and second ends each pivotally connected to a respective one of said stationary and rotatable arm means at a respective location spaced from the door hinge pin whereby such pivotal rotation of said rotatable arm means causes deflection of said spring means to generate a restoring torque operable upon said rotatable arm means in a door closing direction; and

a latch mounted on one of said arm means in selectively releasably retainable engagement with the other of said arm means when said arm means are juxtaposed relative to each other.

2. An automatic door closer adapted for mounting on the conventional hinge of a door via the hinge pin only and adjacent the door frame, comprising:

stationary arm means having a first portion mountable on the door hinge via the door hinge pin and a second portion adapted to abut against the door frame; rotatable arm means having a first portion pivotally mountable on the door hinge via the door hinge pin and a second portion adapted to abut against the door whereby opening rotation of the door about its hinge pin will cause pivotal rotation of said rotatable arm means about the door hinge pin;

spring means having first and second ends each connected to a respective one of said stationary and rotatable arm means at a respective location spaced from the door hinge pin whereby such pivotal rotation of said rotatable arm means causes deflection of said spring means to generate a restoring torque operable upon said rotatable arm means in a door closing direction; and

said spring means end locations are spaced at different distances from the door hinge pin whereby, as said rotatable arm means pivotally rotates about the door hinge pin, the line of force exerted by said spring means between said locations pivots about said location of said stationary arm means for varying the moment arm of said restoring torque.

3. A closer as defined in claim 2 wherein said spring means comprises a substantially constant force spring.

4. A closer as defined in claim 3 wherein said spring is a coil spring.

5. A closer as defined in claim 2 wherein said spring means comprises a coil spring, such connections of said first and second ends are pivotal connections, and said spring includes a coil body having opposite end arms respectively provided with said first and second ends and angularly projecting from said coil body whereby said coil body resides to one side of and parallel to said line of force when said spring is in its normal undefiected position and said coil body deflects arcuately away from said line of force during door opening rotation of said rotatable arm means.

6. A closer as defined in claim 5 further comprising:

7. A closer as defined in claim 5 wherein such distance from the door hinge pin is greater for said rotatable arm means than such distance for said stationary arm means.

8. A closer as defined in claim 7 further comprising:-

a latch mounted on said rotatable arm means in selectively releasably retainable engagement with said stationary arm means when said arm means are juxtaposed relative to each other.

9. An automatic door closer adapted for closing a conventional door which is mounted on a door frame via a hinge and is rotatable about the hinge pin, comprising:

stationary arm means mountable on the hinge pin and adapted to be immobilized relative to the door frame with a first portion located a first distance from the hinge pin;

rotatable arm-means pivotally mountable on the hinge pin with a second portion located a second distance from the hinge pin and adapted to be immobilized relative to the door for rotation therewith about the hinge pin;

spring means having first and second ends pivotally connected to said first and second portions respectively whereby such rotation of said rotatable arm means causes deflection of said spring means; and

latch means mounted on one of said arm means in selectively releasably retainable engagement with the other of said arm means when said arm means are juxtaposed relative to each other.

10. An automatic door closer adapted for closing a conventional door which is mounted on a door frame via a hinge and is rotatable about the hinge pin, comprising:

rotatable arm means pivotally mountable on the hinge pin with a second portion located a second distance from the hinge pin and adapted to be immobilized relative to the door for rotation therewith about the hinge pin, said first and second distances being unequal; and

a substantially constant force coil spring having first and second ends connected to said first and second portions respectively whereby such rotation of said rotatable arm means causes deflection of said spring in an arc, and initial deflection of said spring is more forceful than subsequent deflection for relatively greater door closing force at small door opening angles.

11. A closer as defined in claim 10 wherein said second distance is greater than said first distance.

12. A closer as defined in claim 11 further comprising:

References Cited UNITED STATES PATENTS 50,239 10/1865 Gerard l6l46 1,034,971 8/1912 Brown et a1 l6l46 270,368 l/1883 Barlow 16-76 1,147,827 7/1915 Tanner 16-190 3,157,906 11/1964 Wolf 16-50 3,329,991 7/1967 Gobble l650 BOBBY R. GAY, Primary Examiner R. D. KRAUS, Assistant Examiner