Compact door coordinator

The present invention is a compact door coordinator which includes a relatively narrow housing having mounted therein and extending therefrom a lead control lever and a longer trailing control lever. Both control levers are spring biased to extend from the housing when the doors are open. A relatively simple linkage extends from the lead control lever to the trailing control lever for retaining the ladder in its extended position until the lead door contacts the lead control lever. At that point, the lead control lever is pushed into the housing and rotated against the force of a torsion spring, causing the linkage to move and thereby rotating a cam which then releases the trailing control lever allowing the trailing door to push the trailing control lever into the housing to complete the closing process. When the doors are reopened, the force of the torsion springs causes the lead and trailing levers to once again extend from the housing while resetting the cam to retain the trailing lever in its extended position until it is released.

FIELD OF THE INVENTION
 The present invention relates to coordinators for controlling the
 sequential closing of a pair of oppositely hinged swinging doors in which
 one door is the lead door and the other is the trailing door.
 BACKGROUND OF THE INVENTION
 Closing off large doorways often requires using a pair of doors, and the
 latching mechanisms used with such doors often dictate the sequence in
 which the doors must close to engage the latches. For example, one door
 may carry the latch mechanism while the remaining door must carry the
 receiver or striker mechanism. In a single-door doorway, the striker
 mechanism is mounted to the door frame and engages the latch mechanism
 when the door is closed. In the foregoing example, the door carrying the
 receiver or striker mechanism will be called the "lead door" meaning that
 this door must be closed first in order to correctly engage the latching
 mechanism. The remaining door carrying the latching mechanism will be
 called the "trailing door." Other door arrangements include an overlapping
 strip or astragal intended to close off any gap that may exist between the
 doors when they are in the fully closed position. The astragal must be
 mounted to the trailing door to allow the doors to close.
 Door closing coordinators are well known in the art and serve the function
 of controlling the sequence in which the lead and trailing doors close.
 Door closing coordinators are commonly used in conjunction with doors that
 have some type of automatic door closing mechanism that will move a door
 from an open to a closed position after the door has been released.
 Carrying the foregoing example a bit further both the lead and trailing
 doors have automatic door closing mechanisms which will move the doors to
 a closed position and it is the coordinator's task to ensure that the lead
 door reaches a fully closed position before the trailing door regardless
 of the relative positions the doors are in when they are released, the
 speed with which each door closes, or other variables.
 U.S. Pat. No. 4,429,492 (Imhoff) teaches and describes a door coordinator
 for a pair of oppositely hinged doors which controls the sequence in which
 the doors close by placing a stop proximate the hinge edge of the trailing
 door which props the door open sufficiently to allow the lead door to
 clear it and close. A release mechanism is contacted by the lead door
 which then allows the trailing door to close. Such door coordinators are
 preferably installed in the overhead portion of the door frame or are
 attached to the overhead portion of the door frame.
 U.S. Pat. No. 5,033,234 (Simon et al) teaches and claims a door coordinator
 having a door stop which contacts the trailing door proximate the hinge
 edge of the door and a release mechanism which is contacted by the lead
 door intermediate the hinge edge and free edge of the lead door.
 U.S. Pat. No. 4,949,505 (Cohrs) teaches and describes a door coordinator
 having a door stop which contacts the trailing door intermediate the hinge
 and free edges of the door and a release which, when contacted by the
 trailing door, releases the door stop. This patent uses a sliding carriage
 mechanism which extends between the door stop and the door release.
 U.S. Pat. No. 5,651,216 (Tillmann) teaches and describes a door closer for
 a two-panel door with a closing sequence controlling mechanism having a
 door stop and door release, both of which are mounted to contact the doors
 proximate the hinge edges of the doors.
 U.S. Pat. No. 5,582,472 (Lyons) teaches and describes a solvent storage
 cabinet having a door sequence control mechanism which allows the cabinet
 to close and latch in the event of a fire.
 A product manufactured by the Triangle Brass Manufacturing Company of Los
 Angeles, Calif. designated as its 3092 Retracting Door Coordinator has a
 pair of arms of unequal length extending from an elongated housing. The
 longer of the two arms contacts the trailing door and holds it in an open
 position until the lead door contacts the shorter of the two arms,
 allowing the doors to close. The mechanism used with the Model 3092
 Retracting Door Coordinator requires that the housing have a protuberance
 extending therefrom to enclose the timing mechanism.
 The present invention relates to door coordinators of the general type
 illustrated by the Model 3092 coordinator that provide new, improved and
 more compact construction by enclosing the operating mechanism in a
 housing which is uniform in cross sectional area throughout and which is
 sufficiently compact to allow ease of installation while at the same time
 providing a narrow profile and attractive appearance.
 SUMMARY OF THE INVENTION
 The present invention includes a relatively narrow housing consisting of an
 aluminum tube with a rectangular cross-sectional configuration from which
 extend a lead control lever and a trailing control lever with the trailing
 control lever being longer than the lead control lever. Both control
 levers are spring biased to extend from the housing when the doors are
 open. A relatively simple linkage extending from the lead control lever to
 the trailing control lever retains the trailing control lever in its
 extended position until the lead door contacts the lead control lever, at
 which point the lead control lever is pushed into the housing and rotated
 against the force of the torsion spring, causing the linkage to move and
 thereby rotating a cam which then releases the trailing control lever
 allowing the trailing door to push the trailing control lever into the
 housing to complete the closing process.
 When the doors are reopened, the force of the torsion springs causes the
 lead and trailing levers to once again extend from the housing, while
 resetting the cam to retain trailing lever in its extended position until
 it is released.
 The mechanism is designed to have a pre-set release force at which point
 the trailing control lever will disengage and allow the trailing door to
 close even though the lead door has not yet closed. This feature is
 intended to prevent damage to the trailing door.
 In yet another version of the present invention, means are provided to
 adjust the release force of the trailing control lever.
 BRIEF DESCRIPTION OF THE DRAWINGS
 These and further aspects of the present invention may better be understood
 by referring to the accompanying drawings in which:
 FIG. 1 is a sectional view of a prior art door coordinator taken from U.S.
 Pat. No. 4,429,492;
 FIG. 2 is a top plan view of the present invention showing the control
 levers extended therefrom;
 FIG. 3 is a bottom sectional view of the embodiment shown in FIG. 2 taken
 halfway through the thickness thereof.
 FIG. 4 is an enlarged view of the cam mechanism shown in FIG. 2;
 FIG. 5 is a front plan view of the cam;
 FIG. 6 is a bottom plan view of the cam;
 FIG. 7 is a sectional view of the present invention similar to FIG. 3
 showing the levers retracted;
 FIG. 8 is an enlarged section view of a second embodiment of the present
 invention taken similarly to FIG. 3 of the first embodiment showing the
 release force adjusting mechanism;
 FIG. 9 is a top plan view of the Model 3092 door closer with portions of
 the case removed to reveal the operating mechanism;
 FIG. 10 is an enlarged view of the door closer shown in FIG. 9.
 It is an object of the present invention to provide door coordinator
 mechanisms which are compact in shape and which operate by contacting the
 lead and trailing doors at a point distal from the hinge edge of the doors
 to reduce the force that must be maintained to hold each of the doors in
 an open position.
 It is a further object of the present invention to provide such door
 coordinators and forms where the release force exerted by the lead control
 lever is adjustable.
 While the following describes a preferred embodiment or embodiments of the
 present invention, it is to be understood that this description is made by
 way of example only and is not intended to limit the scope of the present
 invention. It is expected that alterations and further modifications, as
 well as other and further applications of the principles of the present
 invention will occur to others skilled in the art to which the invention
 relates and, while differing from the foregoing, remain within the spirit
 and scope of the invention as herein described and claimed.

DETAILED DESCRIPTION OF THE DRAWINGS
 Referring now to FIG. 1, the numeral 10 identifies generally a doorway of
 the type requiring two doors to close off the door opening. The view of
 FIG. 1 taken in an overhead sectional view has a first wall 12 and a
 second wall 14 defining the left and right vertical segments of the door
 opening defined generally as 16. The remaining portions defining the door
 opening are the floor (not shown) which may or may not have a door jamb
 attached to it within opening 16 and the upper frame 18.
 A lead door 20 is shown hinged to first wall 12 at hinge 22. For purposes
 of convenience, throughout the present description, lead door 20 will be
 described as having a hinge edge 24, which is the vertical edge of door 20
 to which hinges 22 are attached, and a free edge 26 which is the
 vertically extending edge of the door opposite hinge edge 24 and a top
 edge 28.
 FIG. 1 also illustrates a trailing door 30 attached to second wall 14 by
 hinges 32 and having a hinge edge 34, a free edge 36 and a top edge 38
 corresponding to the features described in connection with lead door 20.
 In the illustration, trailing door 30 has a lip 40 which, when doors 20
 and 30 are closed, overlaps door 20, fitting into recess 42 formed along
 the outer portion of door 20.
 In FIG. 1, the door coordinator shown therein has a door stop 44 and a
 release 46 with the door stop 44 being positioned to contact trailing door
 30 proximate hinge edge 34. Holding trailing door 30 open thus requires an
 appreciable amount of force depending upon the weight of door 30 and the
 distance from door stop 44 to the distance point at which the door stop 44
 contacts door 30 to free edge 36. The longer this distance, the greater
 force is applied to door stop 44.
 Referring now to FIG. 2, the numeral 48 indicates generally a door closing
 coordinator constructed in accordance with the teachings of the present
 invention. An elongated cylindrical housing 50 having a generally
 rectangular cross-sectional configuration has a front wall 52, a rear wall
 54, a top 56, and a bottom 58.
 A lead lever 60 having a roller 62 rotatably attached at the end thereof by
 pin 64 extends from housing 50 through lead lever slot 66.
 A trailing lever 68 having a roller 70 rotatably attached to the end
 thereof by pin 72 extends from housing 53 through trailing lever slot 74.
 As seen in FIG. 3, lead lever 60 and trailing lever 68 are spring-biased to
 remain in their extended positions. Lead lever 60 is formed in a generally
 L-shape with a lead lever base 76 integrally formed with a lead lever
 flange 78 with base and flange meeting at approximately a 90.degree.
 angle. A lead torsion spring 80 has a first leg 82, a second leg 84, each
 integrally joined to a coiled center 86. Lead lever 60 is pivotally
 attached within housing 50 at mounting peg 88. As seen in FIG. 3, lead
 torsion spring 80 is also mounted to peg 88 at coiled center 86 thereof
 with first leg 82 resting against flange 78 and second curled portion
 surrounding pin 84a when torsion spring 80 is in its unstressed or
 non-compressed position. As can be seen, torsion spring 80 is compressed
 when lever 60 is rotated in a clockwise direction around peg 88 and thus
 is constantly urging lever 60 to its fully extended position. The outward
 travel of lever 60 is limited by the contact of flange 78 with the
 innermost edge 90 of slot 64.
 In like fashion, trailing lever 68 is formed with a generally L-shaped
 cross section with a base 92 and a flange 94 meeting base 92 at
 approximately a 90.degree. angle. A trailing torsion spring 96 has a first
 leg 98, a second leg 100 and a coiled center 102, corresponding to spring
 80. Lever 68 is pivotally mounted within housing 50 on peg 104 as is
 torsion spring 96, with first leg 98 contacting flange 94 and second leg
 100 contacting the inner surface of rear wall 54. Counterclockwise
 rotation of trailing lever 68 is thus opposed by torsion spring 96 and
 torsion spring 96 which urges lever 68 to its outermost protruding
 position. The outermost rotation of lever 68 is limited by edge 106 of
 slot 74.
 As seen in FIGS. 3 and 4, a linkage 108 has a link 110 which extends from
 trailing lever 68 to a stop cam assembly 112. Stop cam assembly 112 is
 designed to hold lead lever 76 is an extended position and resist rotation
 of lead lever 76 around peg 88 until stop cam assembly is moved by the
 movement of link arm 110 in response to the movement of trailing lever 68.
 This mechanical operation will be described in more detail hereinafter.
 As seen in greater detail in FIGS. 4 and 5, stop cam assembly 112 has a
 stop cam 114 formed in a generally P-shape with a nose 116 and a stem 118
 terminating in a sloped or pitched stem bottom 120. As seen in FIG. 6,
 stem 122 has a slot 124 milled therethrough forming a pair of stem legs
 126 and 128. A pair of apertures 130, 132 are formed through legs 126 and
 128, respectively and are coaxially aligned with one another. A central
 aperture 134 is formed through the P-shaped portion of cam 112 as seen in
 FIG. 6.
 As seen in FIG. 5, the lowermost surfaces 136, 138 of legs 126 and 128 are
 angled or pitched. As seen in FIG. 4, in its at rest position, cam 114 has
 end 140 of nose 116 rest against flange 78 of lever 60 while leg bottoms
 136 and 138 rest flat against the rear wall 54 of housing 50. In this
 position, cam 114 prevents lever 60 from rotating about pin 88.
 Referring now to FIG. 8, it can be seen that link 110 has a first oval
 shape link aperture 142 formed at one end and a second link aperture 144
 formed at the other end. One end of link 110 is slidably attached to lever
 68 by pin 146, inserted through aperture 142. Oval aperture 142 provides a
 lost motion portion for the movement of link 110 that allows the trailing
 arm 60 to move upwardly without pulling the trailing arm 68 downward. The
 trailing arm is allowed to stay fully extended and is biased in position
 by spring 132a mounted around pin 132 at one end of link 110.
 As seen in FIG. 4, the remaining end of link 110 is pivotally attached to
 cam 114 by aligning aperture 148 with cam apertures 130 and 132 and
 passing pin 148 through aligned apertures 130, 144 and 132. As also seen
 in FIG. 4, cam 114 is rotatably mounted to housing 50 by housing pin 150
 which passes through top 56 and bottom 58 of housing 50. In FIG. 5, it can
 be seen that rotating cam 114 in a clockwise direction will move nose end
 140 past the end of flange 78 to position A shown in phantom in FIG. 4,
 thus releasing lever 60 to rotate about pin 88.
 As seen in FIG. 7, rotation of cam 114 occurs when lever 68 is itself
 rotated in a counterclockwise direction to move link 110 which, in turn,
 pushes against pin 148. Thus, in operation, when trailing door 20 contacts
 roller 70, lever 68 is rotated in a counterclockwise direction against the
 force of torsion spring 96 which, in turn, rotates cam 114 in a clockwise
 direction releasing lever 60 and allowing lever 60 to rotate in a
 clockwise direction when contacted by trailing door 30. When doors 20, 30
 are opened, coordinator 48 is reset as torsion spring 80 and 96 rotate
 levers 60 and 68 to their extended or outward position while, at the same
 time, moving link 110 to rotate cam 114 in a counterclockwise position to
 again secure lever 68 against any movement until lever 60 is itself
 rotated.
 Referring now to FIG. 8, the numeral 152 indicates generally an override
 release adjusting mechanism which consists of a bracket 154 extending
 between housing top 56 and housing bottom 58, and sized to leave a gap or
 passageway 156 between bracket 154 and rear wall 54. Bracket 154 has a
 threaded aperture 158 through which an adjusting screw 160 is threaded.
 Surrounding the shank 162 of screw 160 is a coil spring 164, one end of
 which abuts against washer 166 which, in turn, abuts bracket 154, and the
 other end of which is held in place by screw head washer 168. Thus, as
 adjusting screw 160 is threaded into aperture 158, spring 164 is
 compressed.
 An adjusting slide 170 preferably formed as a flat metal segment with a
 rectangular cross-sectional configuration is inserted into housing 50
 through passageway 156. A cam mounting bracket 172 is mounted to slide 170
 at the end distal from bracket 154 and has a cam mounting aperture 174
 through which mounting pin 176 is used to pivotally mount cam 178. Cam 178
 is in its shape, function and operating characteristics substantially the
 same as cam 114 described above. In FIG. 8, link 110 is attached to cam
 178 in the same fashion as described above and serves to rotate cam 178
 when arm 68 is pushed in as described above.
 Operation of the release mechanism may now be described. When a
 sufficiently large force is applied to lead lever 60, the force applied to
 cam 178 will be sufficient to overcome the force exerted by spring 164 and
 slide 170 will move leftward (as depicted in FIG. 8) releasing lever 60
 from cam 178 and allowing lever 60 to be pushed into housing 50. The force
 required to release arm 60 may be adjusted by turning adjusting screw 160
 to either compress or release spring 164. For more specific applications,
 springs 164 of different stiffnesses and rates may
 FIGS. 9 and 10 illustrate the Model 3092 door coordinator described above.
 As can be seen in both FIGS. 9 and 10, the 3092 coordinator 180 has a
 housing 182 from which a pair of arms 184, 186 extend in much the same
 manner as described hereinabove. As best seen in FIG. 10, the timing
 mechanism 188 used in coordinator 180 requires that the housing be
 enlarged to accommodate the internal mechanism, resulting in a housing
 protuberance 190.
 The present invention offers advantages over coordinator 180 in that no
 protuberance is required and the timing mechanism may be wholly contained
 within a relatively inexpensive aluminum tube which is rectangular in
 cross-sectional configuration.
 Use of the present invention may now be described. Coordinator 48 is held
 in position along an uppermost surface of door opening 16 while doors 20
 and 30 are moved toward a closing position in order to determine where
 lead lever 60 and trailing lever 68 may best be positioned. When this
 position is determined, coordinator 48 is secured to upper door frame 18
 by the use of conventional threaded fasteners driven thorough mounting
 holes formed in housing 50 and in a position where doors 20 and 30 may be
 fully closed as though no coordinator is being used.
 When doors 20 and 30 are opened and then released, trailing door 30 will be
 held by lever 68 until lead door 20 closes to contact lead lever 60. As
 door 20 continues to move to a fully closed position, lead lever 60 is
 pushed into housing 50 thereby moving link 110 to rotate cam 114 and
 release trailing lever 68 which, in turn, allows trailing door 30 to move
 to a fully closed position.
 Applying a predetermined override force to trailing door 30 while it is
 being propped open by trailing lever 68 will release trailing lever 68 and
 allow trailing door 30 to close even before lead door 20 has fully closed.
 Although this means that the doors will close out of sequence, this
 feature is intended to prevent damage to trailing door 30 in the event
 that door 30 is struck or hit.
 The override force at which trailing lever 30 will release is adjusted by
 rotating adjusting screw 158 and applying test force to the door to
 determine the appropriate force setting to use.
 While two embodiments of the present invention have been shown and
 described, it will be understood by those skilled in the art that
 improvements and modifications may be made within the scope of the
 invention. Therefore, it is the intent of the appended claims to cover all
 such changes and modifications which fall within the true spirit and scope
 of the invention.