June 19, 1956
`
`H. G. DODGE
`TORQUE SENSITIVE REVERSIBLE MOTION ACTUATOR
`
`2,751,219
`
`Filed Aug. 30, 1954
`
`3 Sheets-Sheet 1
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`INVENTOR.
`Howard G. Dodge
`
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`

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`June 19, 1956
`
`H. G. DODGE
`TORQUE SENSITIVE REVERSIBLE MOTION ACTUATOR
`
`2,751,219
`
`Filed Aug. 30, 1954
`
`3 Sheets-Sheet 2
`
`I
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`
`LL.
`
`INVENTOR.
`Howard G. Dodge
`
`$~~
`
`

`

`June 19, 1956
`
`H. G. DODGE
`TORQUE SENSITIVE REVERSIBLE MOTION ACTUATOR
`
`2,751,219
`
`Filed Aug. 30, 1954
`
`3 Sheets-Sheet 3
`
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`United States Patent Office
`
`2,751,219
`Patented June 19, 1956
`
`1
`
`2,751,219
`TORQUE SENSITIVE REVERSIBLE MOTION
`ACTUATOR
`Howard G. Dodge, College Place, Wash.
`
`Application August 30, 1954, Serial No. 452,850
`2 Claims. (CI. 268-59)
`
`5
`
`2
`In the accompanying drawings:
`Figure 1 is a vertical cross section taken through a
`garage door and a fragmentary portion of a garage having
`portions broken away for convenience of illustration;
`Figure 2. is a vertical elevation of the improved motion
`actuator having its cover removed and upon an enlarged
`scale;
`Figure 3 is a view similar to Figure 2 and showing
`the motion transmitting mechanism swiveled by excess
`10 torque;
`Fignre 4 is a vertical view partially in cross section and
`taken at line 4-4 of Figure 2;
`Figure 5 is a view taken substantially at line 5-5 of
`Figure 4 and having parts broken away for convenience
`15 of illustration; and
`Figure 6 is an enlarged view of the catch mechanism for
`the top of the garage door.
`Figure 7 is a wiring diagram illustrating the electric
`circuit used.
`Referring now in detail to the drawings, Figure 1 dis-
`closes portions which represent at 10 a garage having a
`ceiling or other horizontal support member 11 disclosed
`above the door opening 12 formed in one wall HI' of the
`garage. The garage is supplied with a concrete or other
`25 type floor surface 13 and has a vertically moveable closure
`or door 14 supported by mounting means 15 on the wall
`10' of the garage. To guide movement of the upper edge
`of the door 14 I have disclosed one of a pair of laterally
`spaced horizontally extending parallel guide rails 16 which
`30 extend inwardly of the garage from the wall having the
`opening 12, and moveably carry rollers (not shown)
`journaled on the door 14.
`The motion actuator is indicated in general by the
`numeral 17 and as seen in Figure 1 is supplied with a
`35 metal or other type housing 18 which is removable to
`provide access to the working parts. The actuator is
`supported from the support member U. A V-belt pulley
`19, disposed in a vertical plane, is part of the actuator 17,
`as will be more fully described hereinafter, and has trained
`40 thereabout an endless belt 20 which extends forwardly
`from the pulley 19 and is trained about a second pulley
`21 journaled in any convenient manner upon the wall10'
`of the garage 10 above the opening 12 and midway its
`width. To provide means for applying tension to the belt
`45 20, I provide an idler pulley 22 which is secured to the
`ceiling 11 and the belt 20 is trained thereover.
`Resiliently or securely fastened to the belt 20 is a
`connecting link 23 which is pivotally secured at 24 to
`the. upper end of an angular arm 25 pivoted at 26 to the
`50 door 14. Also secured to the door are a pair of inwardly
`extending laterally spaced ears 27, one disposed at each
`side of the arm 25 and, which journal the ends of a rod
`28 for axial rotation. The rod is provided with a right
`angle latch arm 29 adapted to cooperate with a latch
`55 member 30 anchored to the garage 10 to releasably latch
`the door in the closed position. A spring 31 is provided
`to yieldably hold the latch arm 29 in latching relation to
`the latch member 30 and thus prevent accidental move(cid:173)
`ment of the door from the closed position. However,
`60 the rod 28 is provided with a radially extending actuating
`finger 32 which bears against the arm 25 and is disposed
`in such a position that when the arm 25 is pivoted at
`26 inwardly of the garage the rod 28 is axially rotated
`and the latch arm 29 is moved from the full line position
`to the broken line position shown in Figure 6, thus being
`released from the member 30 and permitting the door to
`open. The arm 25 at the end of its movement strikes
`the rod 28 which constitutes a stop for the arm and
`permits the door to be pulled by the belt 20 throngh the
`70 link 23. and arm 25.
`The subject matter of th.e present invention is con(cid:173)
`tained in an automatically reversible torque sensitive
`
`This invention relates to torque sensitive reversible mo(cid:173)
`tion actuators for producing a desired movement and
`halting the movement when the torque exceeds that nor(cid:173)
`mally required and reversing the actuator upon subse(cid:173)
`quent operation thereof.
`Although not necessarily limited thereto the present 20
`device is admirably suited for the operation of a ver(cid:173)
`tically movable garage door wherein a motor driven
`endless belt is trained about pulleys and is suitably se(cid:173)
`cured to the door intermediate the pulleys so that actua(cid:173)
`tion of the belt will cause the door to be moved to open
`and closed positions. The present application is a con(cid:173)
`tinuation in part of my copending application" Serial No.
`353,636, filed "May 7, 1953, and entitled Garage Door
`Opener, now abandoned.
`Among other advantages and features this invention
`provides means whereby a door such as a garage door
`may be opened and closed by an automatically reversible
`torque sensitive motion actuator which is adapted to halt
`operation upon increase of torque at the motor exceeding
`that required to open and close the door, thus precluding
`the possibility of injury to a person or mutilation of an
`object which may be inadvertently disposed in the path
`of movement of the door.
`Many types of door opening and closing devices have
`been employed to automatically operate garage doors, but
`it has been found to be very difficult to devise a garage
`door operating mechanism which substantially eliminates
`the possibility of damaging the door mounting and/ or
`actuating mechanism or obstruction which may be dis(cid:173)
`posed in the path of movement of the door.
`With this thought in mind this invention contemplates
`electrically actuated door opening and closing means
`wherein movement of the door is instigated by closing an
`electrical circuit through conventional switches and relays
`to actuate an electric motor and provides means for open(cid:173)
`ing the circuit should the torque at the motor increase
`above that required for opening and closing the door.
`It is therefore one object of this invention to provide,
`for operating a garage door, electrically actuated means
`designed to halt operation of the door should the torque
`at the motor exceed the amount required for normal
`movements of the door.
`Another object of the invention lies in the provision of
`an automatically reversible torque sensitive motion actu(cid:173)
`ator which is comparatively simple in construction, strong,
`durable, highly efficient and reliable in use, compact, and
`which may be manufactured at a low cost.
`All of the foregoing and other objects of the invention
`will become apparent from a study of the following speci(cid:173)
`fication taken in connection with the accompanying draw(cid:173)
`ings wherein like characters of reference designate corre(cid:173)
`sponding parts throughout the several views and wherein
`a preferred form of the invention is shown. It should be
`understood however that the drawings and description are
`illustrative only and should not be construed as limiting
`the invention except insofar as it is limited by the prior
`art and the appended claims.
`
`65
`
`

`

`2,751,219
`
`3
`motion actuator indicated in its entirety by the numeral
`17 and briefly consists of a reversible prime mover 33,
`here shown to be an electric motor, having a motor shaft
`34 which constitutes a driving shaft. The motor 33 is
`preferably supported by the frame 35 of the motion actu(cid:173)
`ator but may be supported at any point found convenient
`and desirable. Journaled for rotation upon the frame 35
`I provide a driven shaft 36 which is fixed to and supports
`the pulley 19.
`Intermediate the driven shaft 36 and the
`driving shaft 34 I provide a swivel mounted motion trans(cid:173)
`mitting mechanism 37 which is here shown to be a series
`of belts and pulleys to provide means for transmitting
`the rotary motion from the driving shaft 34 to the driven
`shaft 36 at a greatly reduced speed.
`In this construction the motion transmitting mechanism
`includes a stub shaft 38 which is anchored at right angles
`to rockable arm 39 journaled at 40 coaxial with shaft
`36. To assist in understanding the invention I disclose
`the transmitting mechanism in detail as having a driving
`shaft 34 provided with a relatively small pulley 41 fixed
`thereon. Journaled for rotation on shaft 36 in the plane
`of pulley 41 is a large pulley 42 which is ganged with a
`small pulley 43. A belt 44 is trained about the pulleys
`41 and 42. A belt 45 is trained about the pulley 43 and
`about a large pulley 46 journaled on the stub shaft 38
`and ganged with a small pulley 47. Still another belt 48
`is trained about the small pulley 47 and a large pulley
`49 fixed to the shaft 36. Thus it will be seen that rotary
`motion of driving shaft 34 will impart rotary motion
`to the shaft 36 and therefore will rotate the pulley 19
`causing the belt 20 to move the door 14 to open and
`closed positions.
`The torque at the motor 33 or driving shaft 34 re(cid:173)
`quired to move the door 14 provides reverse torque at
`the pulley 49 and therefore the small pulley 47 en(cid:173)
`deavors to travel an arcuate path defined from the axis
`of shaft 36 and causing the rockable arm 39 to swing
`from the full line position of Figure 2 to the broken
`line position of Figures 2 and 5 or to the full line posi(cid:173)
`tion of Figure 3. Since the arm 39 is disposed above
`the center of gravity I provide yieldable means 50-50
`which are shown to be tension springs that oppose each
`other and yieldably maintain the rockable arm 39 in a
`vertical position. When the torque becomes great enough
`to overcome either spring 50 the arm 39 is caused to
`swivel at 40 according to whichever direction the torque is
`applied.
`The rockable arm 39 is provided with a pair of opposed
`strikers 51 adapted to strike the actuating buttons 52 of
`normally colsed limit switches 53 carried by the frame
`35. As the torque becomes great enough to cause the
`rockable arm 39 to swivel to one side or the order a
`striker 51 contacts the actuator 52 of its companion
`switch 53 and opens the switch thus halting the move(cid:173)
`ment of the garage door.
`Inspection of Figure 4 will reveal that the rockable
`arm 39 is provided with a right angle undulatory finger
`54 which passes intermediate a pair of rockable levers
`55 and 56. As the arm 39 rocks to the right, as viewed
`in Figure 3, the lever 56 is carried by the finger 54 thus
`stretching the spring 50 while the opposed lever 55 is
`supported by a stop 57 carried by the frame 35. Move(cid:173)
`ment of the arm 39 in the opposed direction will cause
`the lever 55 to move therewith and stretch the opposed
`spring 50.
`In Figure 5 it is clearly seen that means are provided
`at 58 to adjust the tension of the springs 50 so that
`sufficient torque may be applied to shaft 36 to cause
`the door to open and close without undue rocking move(cid:173)
`ment of arm 39.
`At its lower end the rockable arm 39 is provided with
`a depending yoke 60 which is adapted to strike and
`actuate a reversing switch 61 carried by the frame 35.
`As the rockable arm 39 swivels to the position where it
`strikes an actuating button 52 of limit switches 53 or 53'
`
`4
`it will simultaneously actuate the reversing switch 61 so
`that subsequent operation of the motion actuator will be
`in a reverse direction from the direction of movement
`present when stopping. Therefore, should the garage
`5 door descend upon the hood or other part of an auto(cid:173)
`mobile or other object, the increased torque will cause
`the actuator to halt and reverse the actuator so that sub(cid:173)
`sequent energizing of the motor 33 will cause the door
`to raise instead of lower. Obviously the garage door
`10 may be stopped at any point upon striking an obstruction
`without doing damage to the door mechanism or the
`obstruction and therefore providing a very safe and con(cid:173)
`venient garage door control means.
`In theoretical practice it appears that the arm 39 will
`15 remain in a position wherein the striker 51 retains the
`actuating button 52 in such position as to maintain the
`limit switch 53 or 53' in an open condition. However,
`in actual practice this is not the case since the springs
`50-50 tend to return the arm 39 to its normal position
`20 when the torque created by the prime mover 33 is re(cid:173)
`leaved and also the slack or lost motion present due
`to the endless belt 20 permits the arm this return move(cid:173)
`ment.
`Associate with the prime mover 33, I employ any one
`25 of a number of conventional wiring circuits preferably
`using a low voltage secondary control circuit in which
`the switches 53 and 53' are interposed to control a mag(cid:173)
`netic relay for selective operation of a primary circuit
`including the prime mover 33 and the reversing switch 61.
`30 Since this circuit may assume a number of various wiring
`organizations which are well known in the art it is not
`thought necessary to enlarge this treatise by a detailed
`disclosure thereof.
`The circuit shown in Figure 7 is a typical motor revers-
`3!i ing circuit embodying the switches 53, 53' and 61. Such
`a circuit is shown, although in greater detail, in the patent
`to Steven No. 2,586,273. Other examples are found in
`the Johnson Patent No. 2,070,832, and in the Chandler
`Patent No. 2,208,119. As is customary in these devices
`40 a manually operable main switch 62 is provided.
`I have disclosed a motion transmitting mechanism for
`convenience of revealing the invention as having a plu(cid:173)
`rality of belts and pulleys, it will be understood, however,
`that gears or other equivalents are encompassed in the
`4!i term "motion transmitting mechanism" and the use there(cid:173)
`of is envisioned.
`Having thus described the invention, what I desire to
`secure by Letters Patent of the United States is:
`1. In a garage door operating mechanism wherein a
`50 door is carried by a mounting and is movable to open and
`closed positions by operation of a reversible drive mecha(cid:173)
`nism, a control device for the drive mechanism compris(cid:173)
`ing a rockable arm interposed in said drive mechanism
`and urged to swing in one direction from a mid point in
`55 response to torque transmitted by the drive mechanism
`when it is moving in one direction and urged to swing in
`the opposite direction in response to torque transmitted
`by the drive mechanism when it is moving in the opposite
`direction, a pair of spring pressed members engaging the
`60 rocker arm at the mid point, one member opposing move(cid:173)
`ment of the arm in one direction from mid point, means
`restraining said member from following the arm when
`it moves in the opposite direction from said mid point,
`the other member opposing movement of the arm from
`65 said mid point in said opposite direction, and means re(cid:173)
`straining the last named member from following the arm
`when the arm moves in said one direction and is opposed
`by the first named member.
`2. A mechanism for operating doors such as garage
`70 doors, comprising a reversible electric motor, an electric
`circuit operably connected to said motor for energizing
`and controlling it, a driving shaft rotatable by said motor,
`a driven shaft, a pivotally mounted motion transmitting
`mechanism operably connecting said shafts and operative
`75 by torque between said shafts to move about its pivotal
`
`

`

`2,751,219
`
`5
`axis, said mechanism including a rockable arm movable
`to and fro, a pair of spring pressed members engaging
`said rocker arm, one member opposing movement of the
`arm in one direction from a normal position, means re(cid:173)
`straining said member from following the. arm when it 5
`moves in the opposite direction from the normal position,
`the other member opposing movement of the arm from
`normal position in said opposite direction, means restrain(cid:173)
`ing the last named member from following the arm when
`the arm moves in said one direction against the opposi- 10
`tion of the first named member, two normally closed limit
`switches in said circuit, each adapted to open the circuit
`and deenergize the motor, one switch being in the path of
`movement of the arm from normal position against the
`
`6
`opposition of one of said members, the other switch being
`in the path of movement of the arm from normal position
`against the opposition of the other member, a reversing
`switch in the circuit operable to reverse the direction of
`rotation of said motor, and means on said arm actuating
`the reversing switch when the arm moves to engage either
`of the first named switches.
`
`References Cited in the file of this patent
`UNITED STATES PATENTS
`Chandler --------------- July 16, 1940
`Wilcox ---------------- Apr. 20, 1954
`
`2,208,119
`2,676,294
`
`