Door closing apparatus

An apparatus for automatically closing a door with respect to a fixed support adjacent thereto which includes a torsional spring, a one-way clutch mechanism and a swash plate hydraulic damper concealably retained within a compact housing. The housing is secured to either the door or the fixed support and a first rotatable portion of the one-way clutch is coupled to the other of either of the door or fixed support so that the first rotatable portion rotates in a first direction when the door is opened in the opposite direction when the door is closed. The torsional spring is at least partially disposed about the one-way clutch mechanism and has one end anchored to the housing and the other end secured for movement with the first rotatable portion. As the door is opened, the first rotatable portion is rotated in the first direction to wind up the torsional spring. When the door is released, the torsional spring unwinds to reverse the process and close the door. As the torsional spring unwinds, the first rotatable portion is driven in the opposite direction causing the one-way clutch mechanism to drive a second rotatable portion in the opposite direction as well. The swash plate hydraulic damper includes a plurality of piston chambers formed in the second rotatable portion, a closed hydraulic circuit interconnecting the piston chambers, and a piston element slidably disposed in each of the chambers for sealing the same and having an end portion extending therefrom. The hydraulic damper includes a wedge-shaped swash plate whose upper surface operatively engages the exposed end portions of the piston elements to restrict the rotation of the second rotatable portion so as to control the rate at which the spring unwinds to close the door. The resistance encountered by the pistons can be selectively varied by adjusting the rotational position of the swash plate with respect to the bottom of the housing. In the preferred embodiment disclosed herein, the compact housing forms the central portion of an ordinary hinge having one plate secured to the door and the other plate secured to the door casing although the housing could be mounted on or within the door itself. The compact assembly of the present invention enables a door to be automatically closed with a relatively constant closing force and provides a means whereby the force may be selectively adjusted.

RELATED CASES 
This application is an improvement over my earlier filed application, Ser. 
No. 735,305, filed on July 16, 1976, now abandoned, for a Spring-Operated 
Door Closer. 
BACKGROUND OF THE INVENTION 
This invention relates to door closers and more particularly to a 
spring-operated door closing apparatus having a hydraulic damper for 
controlling the rate at which a door is closed. 
The prior art teaches many types of door closing apparatus most of which 
are relatively large, bulky and aesthetically unsightly. Most of these 
door closers involve cumbersome lever arm arrangements which do not result 
in a constant closing force and the lever arms often interfere with 
passage through the doorway. Additionally, most of the dampers employed in 
the prior art for controlling the rate at which a door is automatically 
closed are also large and unsightly. 
Typical of the spring-operated door closers of the prior art are U.S. Pat. 
No. 171,171 which issued to J. A. Robbins on Dec. 14, 1875 and U.S. Pat. 
No. 403,922 which issued to J. W. Davis on May 28, 1889. Typical of the 
more modern dampers for controlling the rate at which a door closes in 
U.S. Pat. No. 3,680,181 which issued to R. D. MacDonald on Aug. 1, 1972 
but even these more modern dampers are relatively bulky and unsightly. 
The automatic door closers of the prior art are unable to achive an 
essentially constant force for closing the door as its position changes. 
Many of these door closers are more difficult to open, often do not have 
sufficient force to insure latching as the door approaches its closed 
position and often produce excess force when the door is initially 
released which could cause physical injury or property damage. While a few 
of the dampers of the prior art are adjustable, the adjustments are very 
coarse, are often unreliable and require frequent adjustments depending 
upon door usage. 
The present invention avoids all of the problems and disadvantages of the 
prior art by providing an automatic door closing apparatus which is 
extremely compact and efficient. The door closer of the present invention 
may be concealed within the door itself or mounted thereto. Additionally, 
it may form a portion of a door hinge so as to be concealed within the 
central portion of the hinge itself. The door closer of the present 
invention yields a relatively constant closing force and the swash plate 
hydraulic damper is a highly compact, relatively efficient means for 
selectively controlling the rate at which the door closes. 
BRIEF SUMMARY OF THE INVENTION 
This invention provides a compact apparatus for automatically closing 
doors. The door closer includes a torsional spring, a swash plate 
hydraulic damping apparatus for controlling the rate at which the door 
closes, and a one-way clutch. The one-way clutch is responsive to the 
opening of the door for rotating in a first direction to wind up the 
torsional spring without operating the damping apparatus, but is 
responsive to the release of the door and the unwinding of the torsional 
spring for reversing the process and closing the door. As the spring 
unwinds, the one-way clutch mechanism operates the swash plate hydraulic 
damping apparatus to control the rate at which the door closes so as to 
insure a relatively constant closing force. 
The door closing apparatus may be mounted within a compact housing which 
can be concealably mounted within the door itself or in close proximity 
thereto. In the preferred embodiment, the door closing apparatus is 
embodied in the central portion of a hinge. The hinge has a first hinge 
plate secured to the door casing and a second hinge plate secured to the 
door. The housing which compactly retains the torsional spring, the 
one-way clutch, and the swash plate hydraulic damping apparatus is rigidly 
secured to one of the hinge plates while the other hinge plate is coupled 
to the one-way clutch for operating the assembly. 
The door closing apparatus is extremely compact and does not require a 
large housing thereby enabling it to be installed in a relatively small 
sized hinge assembly. The maximum available diameter of the housing is 
used for the torsional spring so as to achieve the maximum spring force 
for a given housing diameter and the housing may be provided with an 
aperture which provides access to a plurality of adjustment holes on the 
periphery of the swash plate to allow the damping force to be selectively 
adjusted. 
The door closing apparatus is extremely simple and efficient and no large, 
unsightly, bulky apparatus is readily visible thereby improving the 
aesthetic appearance of the area. Additionally, all of the apparatus is 
concealably retained within the housing which can be mounted within the 
door or which can function as a part of the door hinge so as to prevent 
injury and property damage. 
Other advantages and meritorious features of the present invention will be 
more fully understood from the following detailed description of the 
drawings and the preferred embodiment, the appended claims and the 
drawings which are briefly described hereinbelow.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows a door 15 which is swingably mounted to a door casing 16 by 
the automatic door closing apparatus 17 of the present invention. In the 
preferred embodiment, a first hinge plate 18 is secured to the side of 
edge 19 of the door jamb or casing 16 by means of screws 20 or some other 
conventional fastening means and a second hinge plate 21 is secured to the 
side 22 of the door 15 by means of screws 23 or some similar fastening 
means. The first and second hinge plates 18, 21 are coupled together by a 
central hinge portion 24 for hinge-like rotational motion about a hinge 
axis 25. In operation, the door 15 may be opened in the direction 
indicated by the arrow 26 which is counter-clockwise when viewed from 
above along the hinge axis 25 and closed by moving it in a direction 
indicated by the arrow 27 which is clockwise when viewed from above along 
the hinge axis 25. 
FIG. 2 shows the automatic door closing apparatus 17 of the present 
invention embodied in a hinge mechanism as illustrated in FIG. 1. The door 
closing apparatus 17 of FIG. 2 includes a torsional spring 28, a one-way 
clutch assembly 29, and a swash plate hydraulic damper 30, all of which 
are concealably retained in a compact manner within a generally 
cylindrical housing 31 which serves as the central hinge portion 24 of 
FIG. 1. The first hinge plate 18 is rigidly secured to the housing 31 as 
by weld joints 32 or the like and the second hinge plate 21 is coupled to 
the one-way clutch assembly 29. 
In operation, when the door 15 is opened, the second hinge plate 21 is 
caused to rotate about the hinge axis of 25 and winds up the torsional 
spring 28 to store energy therein. When the door is released, the 
torsional spring 28 unwinds to reverse the process and close the door. The 
one-way clutch assembly 29 serves to disable the damper 30 when the door 
is opened but allows it to be operated as the door is closing so as to 
control the rate at which the torsional spring 28 unwinds to close the 
door 15. 
The one-way clutch assembly of FIGS. 2 and 5 include a conventional 
Torrington one-roller clutch having a shaft-like member or pin 33 and a 
collar assembly 34. The collar 34 is an annular member having a plurality 
of rollers 35 disposed about the inner wall 36 thereof. The annular collar 
36 is adapted to receive the shaft 33 therethrough. The rollers 35 are 
disposed in the wall 36 such that the annular collar 34 is able to rotate 
freely with respect to the shaft 33 in a first direction. If, however, an 
attempt is made to rotate the collar 34 in the opposite direction, the 
rollers alter their position to positively grip the shaft 33 so that there 
is no relative motion therebetween thereby causing the shaft 33 to rotate 
in the opposite direction with the collar 34. 
The collar 34 is coupled for rotation with the second hinge plate 21 as the 
door 15 is opened and closed through a first rotatable element 37. The 
first rotatable element 37 includes a channel 38 having its axis aligned 
with the hinge axis 25 for receiving a first end portion 39 of the shaft 
33 in a slip-fit manner so that the shaft 33 is free to rotate within the 
channel 38. Additionally, the first rotatable element 37 includes a collar 
chamber 40 having its axis coincident with the hinge axis 25. The collar 
chamber 40 is so dimensionally adapted to retainably receive the collar 34 
of the one-way clutch assembly 29 in a press fit manner so that the collar 
34 is retainably held by the first rotatable element 37 for rotation 
therewith in either direction. 
A second rotatable element 41 couples the damper 30 to the shaft 33 of the 
one-way clutch assembly 29. The second rotatable element 41 includes a 
shaft channel 42 which has its axis coincident with the hinge axis 25 
formed in one end 44 thereof. The shaft channel 42 is dimensioned so as to 
receiveably retain the opposite end portion 43 of the shaft 33 in a 
press-fit manner so that the second rotatable element 41 can only rotate 
with the shaft 33. 
The second rotatable element 41 has formed therein a plurality of piston 
chambers 45 which converge radially inwardly from the openings 46 at the 
opposite end 47 of the second rotatable element 41 towards the hinge axis 
25 adjacent said one end 44 of the second rotatable element 41. The rear 
portions 48 of each of the piston chambers 45 are interconnected by a 
plurality of fluid paths or channels 49 which converge to meet a common 
chamber 50 located at the innermost end 51 of the shaft channel 42. Since 
the common chamber 50 is closed to the outward flow of fluid therefrom by 
the insertion of the shaft 33 into the shaft channel 42, a closed fluid 
path or circuit is created between the rear portions of 48 of the piston 
chambers 45 and the common chamber 50 via the fluid paths 49 so as to 
allow fluid to flow from one piston chamber 45 to another as required. 
Each of the piston chambers 45 has disposed therein a generally cylindrical 
or bullet-shaped piston element 52 having a fluid contacting rear surface 
53, an O-ring type resilient seal 54 disposed around the piston element 52 
for preventing the escape of fluid from the piston chamber 45 and a head 
portion 55 which is adapted to extend from the piston chamber 45 through 
the openings 46 so that a generally spherical tip 56 is able to contact 
the upper surface 57 of a swash plate 58 which provides the restricting or 
retarding action of the hydraulic damper 30. 
As illustrated in FIGS. 6 and 7 the swash plate 58 is shown to comprise a 
generally circular, disk-shaped element having a generally wedge-shaped 
cross section as viewed along one of its diameters. If a plane 
substantially parallel to the bottom surface 59 of the swash plate 58 were 
to represent a reference plane, then a plane parallel to the upper surface 
57 of the plate 58 would form an acute angle with respect to the 
referenced plane. A plurality of equidistantly spaced apertures 60 are 
provided about the periphery of the plate 58 for adjustment purposes as 
hereinafter described. 
As shown in FIG. 7, the bottom surface 59 is provided with a plurality of 
equidistantly spaced teeth or serrations 61 to prevent slippage of the 
plate 58 within the housing 31. Additionally, as illustrated in FIGS. 2, 5 
and 6, the second rotatable element 41 is provided with a centering member 
62 located on the bottom surface of the opposite end 47 thereof. The 
centering member 62 is located on the hinge axis 25 and is received 
loosely within a centering recess 65 of the swash plate 58 to keep the 
swash plate centered within the housing 31 during operation and during 
rotational adjustments. 
As illustrated in FIGS. 2, 8, 9 and 10, the bottom portion 64 of the 
housing 31 has a generally sloped circular surface 65 upon which the 
bottom surface 59 of the swash plate 58 is disposed. A portion of the 
bottom surface 65 may be provided with teeth or serrations 94 to cooperate 
with the serrations 61 of the swash plate 58 to prevent slippage. The 
housing 31 may also be provided with an access aperture or opening 66 
through which an appropriate tool or instrument can be inserted to engage 
the adjustment apertures 60 about the periphery of the disk-shaped swash 
plate 58 for rotating the swash plate 58 with respect to the stationary 
bottom portion 64 of the housing 31 to selectively vary the damping 
effect. 
FIGS. 8, 9 and 10 show three different positions of the swash plate 58 with 
respect to the bottom portion 64 of the housing 31. In FIG. 8, the swash 
plate 58 is shown as being positioned to produce maximum damping effect 
since the pistons 52 will encounter the greatest or maximum resistance as 
they attempt to rotate in contact with the upper surface 57 of the swash 
plate 58. It will be seen that the angle alpha, which is defined as the 
angle between a horizontal plane perpendicular to the hinge axis 25 and a 
plane parallel to the sloped upper surface 57 of the swash plate 58, is a 
maximum. 
In FIG. 9, the swash plate 58 has been rotated to an intermediate position 
and it will be noted that the angle alpha is something less than it was in 
FIG. 8, indicating that the pistons 52 will encounter less resistance as 
the second rotatable element 41 is rotated when the torsional spring 28 
unwinds. FIG. 10 represents the minimum dampening effect and it will be 
observed that the angle alpha approaches zero as the swash plate 58 is 
turned so that the plane of the upper surface 57 coincides with the 
reference plane. In this position, the pistons 52 of the second rotatable 
element 41 encounter a minimum of resistance and the torsional spring 28 
is able to unwind in a minimally damped or totally undamped state. Any 
degree of damping effect can be achieved between the minimum damping 
action of FIG. 10 and the maximum damping action of FIG. 8 by adjustably 
positioning or rotating the swash plate 58 by means of adjustment 
apertures 60 so as to change the angle alpha and therefore the resistance 
encountered by the extending tips 56 of the piston elements 52. 
The variable damping action described hereinabove is accomplished since the 
displacement of the swash plate-type hydraulic pump 30 increases as the 
angle alpha increases. This means that the total stroke of each of the 
pistons 52 is correspondingly increased, and since the withdrawal motion 
of the pistons 52 as they protrude out of the chambers 45 via openings 46 
is restricted by the upper surface 57 of the swash plate 58, damping 
action results. 
As illustrated in FIGS. 2, 3 and 4, it will be seen that the second hinge 
plate 21 which is rigidly secured to the door 15 has an upper arm portion 
67 retainably secured to an extension 68 of the first rotatable element 
37. The extension 68 is retainably secured within a force fit aperture 69 
located at one end 70 of the arm portion 67 such that the extension and 
the first rotatable element 37 which is integral therewith rotate with the 
second hinge plate 21 as the door 15 is opened and closed. 
The opposite end of the second hinge plate 21 has a corresponding lower arm 
portion 71. The end 72 of the arm 71 has an aperture 73 formed therein. 
The aperture 73 is circular and is adapted to loosely fit over a 
cylindrical post 74 about which the arm 71 is free to pivot. The 
cylindrical post 74 is rigidly secured to the bottom portion 64 of the 
housing 31 by weld joints 75 or by any suitable fastening means. 
The lower end 76 of the cylindrical post 74 is provided with a pair of 
locking slots 77 which are perpendicular to one another. A pair of pivot 
pin mounts 78 are secured to the end 72 of the lower arm portion 71 on the 
side of the post 74 opposite to the side on which the lower arm portion 71 
is located. The pin mounts 78 retainably mount a pivot pin 79 therebetween 
such that a locking lever 80 having an aperture 81 at one end 82 thereof 
may be mounted between the pin mounts 78 such that the pivot pin 79 passes 
through the aperture 81 and mounts the locking lever 80 for pivotal 
rotation about the axis of the pivot pin 79. 
When the door is opened such that the second hinge plate 21 forms an angle 
of 90 or an angle of 180 with the hinge plate 18, the locking lever 80 may 
be manually operated such that an intermediate portion 83 thereof may be 
placed within one of the two locking slots 77 to lock the door in that 
predetermined position. The opposite end 84 of the locking lever 80 has a 
cross bar 85 generally perpendicular to the axis of the locking lever 80 
and a pair of upwardly disposed tines 86 adapted to be disposed on both 
sides of the lower arm portion 71 for manual gripping and to further 
insure locking when the door is in the 180.degree. position. 
The operation of the door closing apparatus of the present invention will 
be described with reference to FIGS. 1, 2, 4 and 5. When the door 15 is 
opened, the second hinge plate 21 rotates with the door 15 and the upper 
arm portion 67 which is secured to extension 68 causes the first rotatable 
element 37 to rotate in a first direction about the hinge axis 25. Since 
the first rotatable element is secured to the collar 34 of the one-way 
clutch assembly 29, the collar 34 rotates freely with respect to the shaft 
39 without causing the shaft to rotate. Therefore, the damper 30 is not 
operated while the door is being opened but the torsional spring 28 is 
wound up to store energy therein as the first rotatable element 37 rotates 
in said first direction. 
When the door is released, the energy stored in a torsional spring 28 is 
released and the spring 28 is unwound to rotate the first rotatable 
element 37 and hence the collar 34 in the opposite direction. When the 
collar 34 starts to rotate in the opposite direction, the rollers 35 
positively grip the shaft 33 so that the shaft 33 rotates in the opposite 
direction with the first rotatable element 37 as the torsional spring 28 
unwinds. As the shaft 33 rotates in the opposite direction as the spring 
28 unwinds, it causes the second rotatable element 41 which is secured 
thereto to rotate in the opposite direction as well. The rotation of the 
second rotatable element 41 causes the tips 56 of the piston elements 52 
to bear against the upper surface 57 of the swash plate 58. As the piston 
elements 52 move in and out of the piston chambers 45 in accordance with 
the adjusted position of the swash plate 58 with respect to the sloped 
surface 65 of the bottom of the housing 31 the damping effect is achieved. 
The tilt angle of adjustment of the swash plate 58 determines the amount 
of restricting or retarding effect produced by the damper 30 and therefore 
controls the rate at which the torsional spring 28 unwinds to close the 
door 15. To reduce friction, an annular thrust washer (not shown) may be 
placed between tips 56 of pistons 52 and the upper face of swash plate 58, 
the central opening of such washer providing clearance for centering 
member 62. 
Additionally, the door may be locked at either the 90 or the 180 position 
by positioning the locking lever 80 within one of the locking slots 77 on 
the bottom end 67 of the cylindrical post 74 if desired. If it is 
desireable to increase or decrease the amount of damping, the position of 
the swash plate 58 with respect to the sloped surface 65 of the bottom 64 
of the housing 31 may be varied by the insertion of a tool or adjustment 
instrument within the access port 66 to engage the adjustment apertures 60 
about the periphery of the swash plate 58 for rotating the plate 58 about 
the axis of rotation or hinge axis 25 to vary the angle alpha. 
In practice, maximum utilization is made of the available diameter ("d" in 
FIG. 3) of the housing 31 since the torsional spring 28 is disposed 
immediately radially inwardly of the walls of the housing 31 so as to give 
maximum spring force for a given diameter of the housing 31. One end 87 of 
the torsional spring 28 is secured to the first rotatable element 37 while 
the opposite end 88 of the torsional spring 28 is anchored to the housing 
31 as by insertion through an anchoring aperture 89 or the like. The vent 
90 provides an escape path for the air which is within the shaft channel 
42 when the end portion 43 of the shaft 33 is force fitted into the 
channel 42. 
While the preferred enbodiment of the present invention has been disclosed 
with specific reference to incorporation within a hinge, it will be 
understood that the same unit with or without the housing 31 could be 
employed in the environment set forth in applicant's copending application 
cited above, the disclosure of which is incorporated by reference herein. 
With this detailed description of the specific apparatus used to illustrate 
the prime embodiment of the present invention and the operation thereof, 
it will be obvious to those skilled in the art that various modifications 
can be made in this door closing apparatus without departing from the 
spirit and scope of the present invention which is limited only by the 
appended claims.