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Publication numberUS3425161 A
Publication typeGrant
Publication dateFeb 4, 1969
Filing dateOct 17, 1967
Priority dateOct 17, 1967
Publication numberUS 3425161 A, US 3425161A, US-A-3425161, US3425161 A, US3425161A
InventorsJohn C Catlett, James R Gilson
Original AssigneeGyro Tech Door Co
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Automatic balanced door with transom mounted operator
US 3425161 A
Abstract  available in
Images(5)
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Claims  available in
Description  (OCR text may contain errors)

Feb. 4, 1969 I j c, CATLETT ET AL 3,425,161

AUTOMATIOBALANCED DOOR WITH TRANSOM MOUNTED OPERATOR Filed Oct. 17. 1967 Sheet of 5 INVENTORS JOHN C. CATLETT & JAMES R. GILSON BY Q2 a /6 4 ATTORNEY Feb. 4, 1969 J g, CATLETT ET AL 3,425,161 AUTOMATIC BALANCED DOOR WITH TRANSOM MOUNTED OPERATOR Filed Oct. 17, 1967 BY @601 W,

ATTORNEY Feb. 4, 1969 CATLETT ET AL 3,425,151

AUTOMATIC BALANCED DOOR WITH TRANSOM MOUNTED OPERATOR Filedpct. 17, 1967 Sheet 3 of 5 FIG.6

INVENTORS JOHN C.CATL ETT & JAMES R. GILSON BY KM ATTQRNEY Feb. 4, 1969 J. c, CATLETT ET AL 3,425,161

AUTOMATIC BALANCED DOOR WITH TRANSOM MOUNTED OPERATOR Filed 0d. 17, 1967 Sheet 4- of 5 FIG. 7

INVENTORS JOHN C. CATLETT 8- JAMES R.G|LSON ATTORNEY Feb. 4, 1969 AT ET ET AL 3,425,161

AUTOMATIC BALANCED DOOR WITH TRANSOM MOUNTED OPERATOR Filed Oct. 17, 1967 lNVENTOR S JOHN C. CATLETT 8. JAMES R. GILSON ATTORNEY United States Patent 3,425,161 AUTOMATIC BALANCED DOOR WITH TRANSOM MOUNTED OPERATOR John C. Catlett and James R. Gilson, Memphis, Tenn., as-

signors to Gyro-Tech Door Company, Memphis, Tenn., a corporation of Illinois Filed Oct. 17, 1967, Ser. No. 675,933 U.S. Cl. 49-253 12 Claims Int. Cl. Ed 15/30; E05f 15/02, 15/10 ABSTRACT OF THE DISCLOSURE A door having a balanced hinge arrangement and a compact power unit for elfecting swinging of said door about a pivot axis located inwardly of the jamb of the door frame; said power unit being mounted within the transom or lintel of the door frame and being connected to said door by linkage, said power unit having a motor, a gear train for transmission of the motive power to an operating shaft for door opening operation; said gear train effecting a speed reduction during door opening operation; there being a compression spiral spring adapted for storing of energy upon door opening to provide the force for the door closing operation with the said gear train effecting a speed increase during such closing operation.

Background of the invention Heretofore with automatic balanced doors, the power units therefor have been mounted within the door frame for travel with the door during opening and closing operation. However, such constructions have, understandably, caused a marked increase in the weight of the door necessitating requisite considerations of strength of materials used, adequate mounting of pivot arms, etc. Furthermore, in case of break down, the doorway would become unusable during repair or there might be required the entire removal of the door.

Summary of the invention It is an object of the present invention to provide a door having a balanced hinge arrangement and a door operator for use therewith, which operator is mounted within the transom or lintel of the door frame.

It is another object of the present invention to provide an automatic balanced door of the type stated having a transom-mounted door operator to which access may be readily elfe-cted for purposes of inspection or repair and which would allow for simultaneous disengagement from the door so that the door may be usable during such periods.

It is another object of the present invention to provide an automatic balanced door of the type stated having an operator which incorporates a novel motion transmitting system so as to bring about smooth and reliable door operation and which system, by its simplicity, is resistant to break down.

It is a further object of the present invention to provide an automatic balanced door having an operator therefor mounted within the lintel or transom of the door frame which latter incorporates a motion transmitting system allowing for speed reduction when under influence of the main power unit and which will allow of speed increase when driven through the release of tension upon a spiral spring to thereby assure consistent door swinging operation in a manner safe to all users.

It is a still further object of the present invention to provide an automatic balanced door having a transommounted operator which may be most economically manufactured; the components of which operator are adapted for minimal wear so as to cond-uce to longevity; which operator does not require constant maintenance; and

FIGURE 1 is a front view of an automatic balanced door constructed in accordance with and embodying the present invention.

FIGURE 2 is a plan view taken on the line 2-2 of FIGURE 1 and showing the door in closed condition.

FIGURE 3 is a plan view taken substantially on the line 2-2 of FIGURE 1 but illustrating the door in open condition.

FIGURE 4 is a horizontal view taken on the line 4-4 of FIGURE 1 with the casing broken away.

FIGURE 5 is a top view of the electrical switches and related components as viewed on the line 5-5 of FIG- URE 1.

FIGURE 6 is a vertical transverse sectional view taken on the line 6-6- of FIGURE 4.

FIGURE 7 is a vertical transverse sectional view taken on the line 7-7 of FIGURE 4.

FIGURE 8 is a fragmentary front view as viewed on the line 8-8 of FIGURE 2.

FIGURE 9 is an enlarged fragmentary top plan view as taken on the line 9-9 of FIGURE 8.

Description of the preferred embodiment Referring now by reference characters to the drawings which disclose the prefered embodiment of the present invention, 1 generally designates a door for disposition within a doorway w defined by a frame B incorporating vertical jambs 2, 3, a transom or lintel 4 and a base 5. Door 1 comprises vertical rails 6, 7, and upper and lower leaves 8, 9, respectively, which are preferably formed of metal and are adapted tosupport transparent panels 10 as of glass, or other desirably transparent material. The jambs 2, 3 and transom 4 of frame B are preferably produced through extrusion so as to constitute casings 2', 3', 4, respectively, which are of four-sided character to present interior volumes for purposes presently appearing.

Door 1 is of the balanced type, being related to door frame B for swinging about an axis located inwardly of jamb 3 whereby, upon such swinging into open condition, a part of door 1, as indicated at a (FIGURE 3) will swing inwardly and the other equal part, as indicated at b, will swing outwardly, with door 1 being thus folded back toward jamb 3 (for purposes of orientation, outwardly will be in a direction toward the upper end of the drawing sheet).

Provided interiorly of jamb 3 is a hinge shaft 11 (FIG- URES 4 and 7) which may be of tubular form and terminating at its upper and lower ends proximate the upper and lower edges of door leaves 8, 9, respectively.

Suitably fixed within the upper and lower ends of hinge shaft 11 for rotation therewith are the hubs (not shown) of upper and lower door pivot arms or levers 12, 13, respectively, which latter are axially normal to shaft 11 and are suitably journ'aled in bearings within jamb 3 in the manner more fully set forth and described in our copending patent application Serial No. 625,246, filed March 22, 1967. Each pivot arm 12, 13 has an effective length substantially one-fourth the transverse extent of door 1 and is, at its outer end, receivable within recesses 14, 15, respectively, formed in the related door leaf 8, 9, respectively, so that when said door 1 is in closed condition each pivot arm 12, 13 will, throughout the substantial portion of its extent be surfacewise aligned with the related door leaf (FIGURE 2). The jamb-remote end of each pivot arm 12, 13 is suitably engaged, as by a hinge pin (not shown) to the related door leaf 8-, 9' respectively; there being preferably a thrust and needle bearing arrangement therefor as of the type shown and described in our aforesaid application. As stated, the casing 4' of transom 4 is of generally four-sided character (see FIG- URE 6) having front and rear walls 16, 17, respectively, and top and bottom walls 18, 19, respectively, for defining a chamber co-extensive with transom 4. Mouted within chamber 20 spacedly from jamb 3 is a motor 21, as desiralbly of the direct current shunt wound type, being provided with a permanent magnet (not shown) which may be a single circular magnet surrounding the motor armature (not shown) or may comprise a plurality of circumferentially spaced magnets disposed around the armature to provide a permanent magnetic field for the motor in accordance with well known practice. Motor 21 is adapted for actuation by a suitable electric switch, including, for example, switch-type floor mats (not shown) through a series of electrical relays (not shown) presented Within an electrical control box, as indicated at 22, in FIGURE 1, compactly disposed within transom chamber 20 and positioned proximate jamb 2. The actuating switch whether it be the switch-type fioor mat or otherwise is connected in any well known manner to control box 22. It should be recognized that the door of the present invention may be operated by actuation of any desired type of switch such as 'a photoelectric cell, a sonic switch, mechanical switching devices and the like.

Motor 21 is provided with a main shaft 23 which is coupled with a coaxial input shaft 24 by means of a clutch C which may be of the slip-type having a male driving member 25 for cooperating with a female driven member 26 mounted, as by a set screw 27, upon input shaft 24. Thus, frictional engagement will be maintained between the confronting faces of members 25 and 26 so long as a prdetermined speed of rotation is not exceeded. However, if such critical speed is surpassed, engagement between said members 25, 26 will be broken by slipping so that transmission between shafts 23 and 24 will be discontinued.

Input shaft 24 extends through an opening 28 formed in a partition 29 of an operator housing 30 presented within transom chamber 20', there being a bearing 31 for journaling of said shaft 24. The clutch remote end of input shaft 24 extends beyond partition 29 and into an enlarged compartment D; and on its projecting end mounts a driving bevel gear 32 for meshing with a driven bevel gear 33 fixed upon the lower end portion of a vertically presented shaft 34, the lower end upper ends of which are journaled within suitable bearings 35, 36, respectively, within the upper and lower walls 37, 38, respectively, of compartment D. Carried upon the upper portion of shaft 34 is a gear 39 of a gear train indicated generally at 40; said gear 39 meshing with a pinion 41 fixed upon the upper end of a shaft 42 presented in spaced apart, axially parallel relationship to shaft 34 and being similarly journaled at its upper and lower ends with suitable bearings 43, 44, respeotively, within recesses in said housing walls 37, 38, respectively. On the lower portion of shaft 42 there is provided a relatively enlarged gear 45 for engagement with a pinion 46 secured on a shaft 47, axially parallel to shafts 42 and 34, and being journaled in a like fashion at its upper and lower ends in bearings 48, 49, respectively, within recesses in walls 37, 38, respectively. Shaft 47 in its upper portion, proximate upper wall 37, mounts a driving gear 50 which engages a pinion 51 mounted upon a driven shaft 52, axially parallel to the intermediate shafts 34, 42 and 47 and being journaled at its upper and lower ends in bearings 53, 54, respectively, disposed within recesses provided in the upper and lower walls of housing 30. Substantially intermediate its length driven shaft 52 carries a 'drive gear 55 for meshing engagement with a pinion 56 upon an output shaft 57 (FIGURE 6) which, though axially parallel to drive shaft 52, is located outwardly thereof within a plane therewith which is normal to the plane passing through shafts 34, 42 and 47. Output shaft 57 is journaled as by radial thrust bearings 58 in its upper end portion within upper wall 37 of housing 30 but projects upwardly thereof to provide an extension 59 for purposes presently appearing. In its lower portion output shaft 57 is journaled within a needle bearing 60 disposed within an opening 61 in bottom wall 38 of housing 30, with its lower end extending downwardly through said opening 61 and through a registering aperture 62 in bottom wall 19 of transom 4 for fixed engagement of its extremity within a boss 63 integrally formed at one end of an arm 64 which may be of forged steel, and presented within a plane normal to that of door 1, whereby swinging of said arm 64 will be effected upon rotation of output shaft 57. Thus, the lower end of output shaft 57 will :be disposed proximate upper door leaf 8. The outer or other end of arm 64 is hingedlly engaged, as by a pin 65, to one end of a cooperating link 66, the other end of which is pivoted upon a flange 67 of a mounting bracket 68 secured on upper door leaf 8 so as not to interfere with door closure. Link 66 may be of turnbuckle character, as constituting a main element 69, internally threaded at each of its ends for engagement to swivel members 70, 71 to permit of appropriate linear adjustment.

Between pinion 56 and bearing 60, output shaft 57 is provided with an elongated, lengthwise extending slot 72 for rigidly receiving one end of a compression spring 73 of spiral character, disposed eccentrically about shaft 57 and with its opposite or other end being secured to a side wall portion 74 of an annular sub-chamber 75 within compartment D.

Spring 73 may be pre-loaded.

The upper end extension 59 of output shaft 57 mounts a plate cam 76 for causing timed actuation of a latch switch 77 having a spring biased cam follower 78 for engaging the operating edge 79 of said cam 76. The switch system of the present door construction is but generally indicated in FIGURE 5 as incorporating a safety switch 80 and a door slow-down switch 81. However, the particular electrical switches and circuitry utilized do not form a part of the present invention and are shown merely for the purpose of completeness, as the same function in the same manner, and serve the same purpose as like switches in current automatic balanced doors, but in the instant construction are located in an unusual position for integration with the transommounted operator.

Carried upon upper door leaf 8 for extension above the upper surface thereof is a guide roller 82 being adapted for free rotation in a horizontal plane about a mounting shaft (not shown). Guide roller 82 is received within an elongated, downwardly opening recess or channel 84 provided in the bottom wall 19 of transom 4 and presenting a constricting path of movement for said roller 82. As may best be seen in FIGURE 3 guide channel 84 extends from immediately proximate side jamb 3 to a point slightly beyond the middle of bottom wall 19; there being :1 preferably resilient stop block 85 as of rubber or the like, presented at the jamb-adjacent end of said channel 84 for cushioning the impact therewith of roller 82 during door opening operation.

From the foregoing, the operation of door 1 may become readily apparent. With door 1 in closed condition, as seen in FIGURE 2, the particular system activating switch, whether it be a switch mat, photoelectric cell, or the like, is actuated thereupon causing motor 21 to be energized with consequent rotation of main shaft 23. R0- tation of input shaft 24 will be effected by reason of the coupling through clutch c and such rotary motion will then be transmitted through an angle of degrees by the meshing of driving and driven bevel gears 32, 33, respectively, resulting in rotation of driven shaft 52 by means of gear train 40, wherein intermediate shafts 34, 42, and 47 will rotate through intermeshing of the respectively mounted gears and pinions. Output shaft 57 will rotate through engagement of gears 54, 56 resulting in a swinging of arm 64 for drivingly pushing link 66 thereby causing door 1 to be swung into open condition as shown in FIGURE 3. During such door opening action, guide roller 82 will be moved along the linear, constraining path created by guide channel 83 with such travel being terminated by abutment of roller 82 against stop block 85 thereby completing the door-opening movement. Guide roller 82 thus serves as a counter-balancing force to assure movement of door 1 in a predetermined path as guide roller 82 cooperates with channel 83 in a camming manner. The swinging movement of door 1 is also controlled by pivot arms 12, 13 in a well known understood manner.

The rotation of output shaft 57 during door-opening movement will cause a tight winding of spring 73 thereabout for compressing same and causing the storing of mechanical energy by such stress. With the particular switch arrangement and motor of the present invention, the voltage to motor 21 will be reduced during dooropening operation, all in accordance with known systems. With low voltage being applied to motor 21, the same will stall out when door 1 is in open position, or, in other words, when guide roller 82 abuts stop block 85, with such stalling serving as a brake or holding force. Door 1 will remain in open position (FIGURE 3) as long as the actuating switch for motor 21 is closed. However, when said switch is opened, as by a person passing from the switch mat, all power to motor 21 is cut off. Thereupon the energy stored in spring 75 is released to cause output shaft 5-7 to rotate in the direction opposite that to which it rotated under influence of motor main shaft 23 for door opening. By such rotation of output shaft 57, gear train 40, including driven shaft 52, between said output shaft 57 and motor main shaft 23 will be in reverse relationship to that during door-opening operation so that a relative increase in speed of rotation of said intervening shafts 34, 42, 47 will be effected with consequent rotation of main shaft 23 resulting in rotation of the motor armature (not shown) so as to cause the motor to act as a dynamic brake. It is understood that the gears and pinions of gear tarin 40 are so inter-related as to cause a speed reduction between motor main shaft 23 and output shaft 57 for door opening, whereby a speed increase will be developed between same under the driving force of the releasing of spring 73.

Thus, motor 21 becomes a generator creating a braking resistance between the armature and the permanent magnet field. The motor armature is connected to a closed electrical circuit (not shown) which includes variable resistors, so that the closing speed may be increased or decreased by appropriate adjustment of the said resistors. It will, therefore, be seen that in the door open-ing operation, motor 21 serves as the motivating force, while in the door closing operation, spring 83 provides the requisite force. I

It should be understood that changes and modifications in the formation, construction, and arrangement and combination of the several parts of the automatic balanced door with transom mounted operator may be made and substituted for these herein shown and described without departing from the nature and principle of our invention. I

Having thus described our invention, what we claim and desire to obtain by Letters Patent is:

1. In combination with a balanced door having a door frame comprising a header, a pair of side jambs, and a base, which members define a door opening, one of said jambs having a chamber, a hinge shaft mounted in said chamber, a door provided in said opening, lever means connecting said hinge shaft and said door spacedly from the related jamb, and a door operator for effecting closing and opening operation of said door, said door operator being mounted within said header and comprising a prime mover having a main shaft, an input shaft, means coupling said main shaft and said input shaft, a drive shaft, gear means connecting said input shaft and said drive shaft, an output shaft, link means connecting said door operator and said door, means connecting said output shaft to said link means, and motion transmitting means connecting said drive shaft and said output shaft.

2. The combination as defined in claim 1 and further characterized by said drive shaft and said output shaft being in axially parallel relationship and vertically disposed with respect to said door and further characterized by said link means comprising a first arm and a second arm, said first arm being engaged to said output shaft and said second arm being engaged to said door.

3. The combination as defined in claim 2 and further characterized by said first arm being in planar normal relationship to said output shaft for movement within a horizontal plane responsive to rotation of said output shaft, and means pivotally interconnecting said first and second arms.

4. The combination as defined in claim 1 and further characterized by said gear means comprising a plurality of gears of predetermined ratio so as to effect a speed reduction between said input shaft and said output shaft during door opening operation.

5. The combination as defined in claim 1 and further characterized by said gear means comprising a plurality of intermeshing gears, shaft means for supporting each gear in said gear means, each shaft in said gear means being in mutually axially parallel relationship and in axially normal relationship to said input shaft whereby the gears Will be caused to rotate in horizontal planes, said drive shaft and said input shaft being axially parallel to the shafts in said gear means.

6. The combination as defined in claim 1 and further characterized by a compression spring engaged about said output shaft for stressing upon rotation of the latter during door opening operation.

7. The combination as defined in claim 2 and further characterized by a compression spring provided encirclingly of said output shaft for compression thereabout during door opening operation for providing energy for door closing operation, and said prime mover being of a permanent magnetic character.

'8. In combination with a balanced door having a door frame comprising a header, a pair of side jambs and a base which members define a door opening, one of side jambs having a chamber, a hinge shaft mounted in said chamber, a door provided in said opening, lever means connecting said hinge shaft and side door spacedly from the related jamb, and a door operator for effecting closing and opening of said door, said door operator being mounted within said header and comprising a prime mover, a drive shaft provided in said prime mover for rotation about an axis extending lengthwise of said header, a vertically presented output shaft in axially normal relationship to said drive shaft, gear means interconnecting said drive shaft and output shaft for rotation of the latter about a vertical axis, and link means connecting the end of said output shaft and said door.

9. The combination as defined in claim 8 and further characterized by said link means comprising a first arm secured at one of its ends with said output shaft, a second arm pivotally engaged to said first arm at the end thereof remote from its connection to the output shaft, and means pivotally engaging the other end of said second arm to said door.

10. The combination as defined in claim 9 and further characterized by said first and second arms being disposed in planar parallel relationship, and means for adjusting the length of at least one of said arms.

11. A combination as defined in claim 8 and further characterized by a compression spring disposed eccentrically about said output shaft for influencing said shaft to rotate in a direction for releasing energy stored in said spring.

12. A combination as defined in claim 11 and further characterized by said gear means comprising a plurality of gears arranged for rotative movement about vertical 7 8 axes parallel to the axis of rotation of said output shaft 2,637,877 5/ 1953 Hanssen 49-386 X and normal to the axis of rotation of said drive shaft. 3,247,617 4/ 1966 Catlett 49--107 References Cited UNITED STATES PATENTS 2,019,528 11/1935 Ellison 49-248 2,059,143 10/1936 Renwick 49-251 X 49 34 2,207,365 7/1940 Williams 49-246 X 0 DAVID J. WILLIAMOWSKY, Primary Examiner.

5 J. KARL BELL, Assistant Examiner.

US. Cl. X.R.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2019528 *Jul 30, 1932Nov 5, 1935Ellison Bronze Company IncBalanced door
US2059143 *Dec 17, 1934Oct 27, 1936William R RenwickDoor mounting
US2207365 *Apr 20, 1936Jul 9, 1940Clark Equipment CoDoor operating mechanism
US2637877 *Apr 20, 1948May 12, 1953Ellison Bronze Company IncBalanced door
US3247617 *Nov 3, 1961Apr 26, 1966Roto Swing Door Co IncTwo way automatic door
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3675370 *Jun 1, 1970Jul 11, 1972John C CatlettAutomatic balanced door with concealed drive
US3918205 *May 7, 1974Nov 11, 1975Rasmussen V B KWindow, particularly for being mounted in an inclined roof
US4045914 *Sep 8, 1975Sep 6, 1977The Stanley WorksAutomatic door operator
US4222147 *Mar 20, 1978Sep 16, 1980Reading Door Closer Corp.Door closer with assist or door operating features
US4267667 *Aug 30, 1979May 19, 1981Ingham Gary GBalanced door
US4286411 *Sep 6, 1979Sep 1, 1981Wikk Industries, Inc.Manual balanced door with door closer arm
US4658545 *Jun 17, 1985Apr 21, 1987Ingham Steven GAutomatic door opener and closer
US5193647 *Mar 23, 1992Mar 16, 1993Thomas Industries, Inc.Easy opening door control device
US5243735 *Mar 9, 1992Sep 14, 1993Thomas Industries, Inc.Regenerative feedback door control device with one-way clutch
US5878530 *Jan 21, 1997Mar 9, 1999Eccleston MechanicalRemotely controllable automatic door operator permitting active and passive door operation
US6058665 *Mar 10, 1998May 9, 2000Steelcase Development Inc.Adjustable door and doorway construction
US6336294Feb 4, 2000Jan 8, 2002The Stanley WorksAutomatic door assembly and door operator therefor
US6347485 *Jul 28, 1999Feb 19, 2002Thomas J. HebdaPower assist for moving a door between a closed and an ajar position
US6481160Aug 1, 2000Nov 19, 2002The Stanley WorksAxial door operator
US6513859 *Sep 20, 2001Feb 4, 2003Ohi Seisakusho Co., Ltd.Opening and closing apparatus for an opening and closing member of a vehicle
US6530178Feb 4, 2000Mar 11, 2003The Stanley WorksAutomatic door assembly and door operator therefor
US6786006Jan 10, 2003Sep 7, 2004The Stanley WorksAutomatic door assembly and door operator therefor
US8169169Feb 13, 2009May 1, 2012Brian HassDoor operator for controlling a door and method of same
US8415902Apr 16, 2010Apr 9, 2013Yale Security Inc.Door closer with calibration mode
US8434281 *Jun 3, 2007May 7, 2013Hardoor Mechanisms Production Ltd.System and device for stiffening a door
US8527101Apr 16, 2010Sep 3, 2013Yale Security Inc.Door closer assembly
US8547046Apr 16, 2010Oct 1, 2013Yale Security Inc.Door closer with self-powered control unit
US8564235Apr 16, 2010Oct 22, 2013Yale Security Inc.Self-adjusting door closer
US8600567Mar 25, 2011Dec 3, 2013Yale Security Inc.Door closer assembly
US8773237Apr 16, 2010Jul 8, 2014Yale Security Inc.Door closer with teach mode
US8779713Apr 16, 2010Jul 15, 2014Yale Security Inc.Door closer with dynamically adjustable latch region parameters
US20090193736 *Jun 3, 2007Aug 6, 2009Hardoor Mechanisms Production Ltd.System and Device for Stiffening a Door
EP0562153A1 *Jun 26, 1992Sep 29, 1993Thomas Industries Inc.Easy opening door control device
WO1981000587A1 *Aug 25, 1980Mar 5, 1981G InghamBalanced door
WO2001009467A1 *Jul 26, 2000Feb 8, 2001Thomas J HebdaPower assist for moving a door between a closed position and an ajar position
WO2002072989A1 *Feb 22, 2002Sep 19, 2002Rotodor AgDevice for pulling or pushing a door leaf
Classifications
U.S. Classification49/253, 49/340
International ClassificationE05F15/12, E05D15/30
Cooperative ClassificationE05F15/127, E05Y2201/236, E05Y2800/11, E05Y2900/132, E05D15/30, E05Y2201/216, E05Y2900/00
European ClassificationE05D15/30, E05F15/12H