CA1108198A

CA1108198A - Door operating mechanism

Info

Publication number: CA1108198A
Application number: CA302,907A
Authority: CA
Inventors: Tebor Mitro
Original assignee: Individual
Current assignee: Individual
Priority date: 1978-05-09
Filing date: 1978-05-09
Publication date: 1981-09-01

Abstract

TITLE
DOOR OPERATING MECHANISM

INVENTOR

Tebor MITRO

ABSTRACT

A novel door mechanism for use with vertically movable doors, in one aspect;
(a) eliminates the need for torsion springs, drums, and cables in the operator. This eliminates bird nesting and other ailments associated with that species of doors; and, (b) in vertical lift doors eliminates one of the many counter weights.
This is achieved by use of a door moving control line which has flex in only one plane in eg. that the plane is orthogonal to the linear extent of the control line.

Description

~1~381~8 This invention relates to a door operating mechanism and in particular a mechanism for moving a door in the vertical along a track or rails under operator control.
Typically, vertically movable doors are used as garage doors in domestic, industrial or military applications.
There are several species of such doors.
One specie is a sectional vertically movable overhead door. It has a plurality of articulating panel members which extend horizontally the whole width of the door opening.
Each panel is hinged to its adjacent panels and rollers are provided at the side margins of the panels. The rollers are adapted to engage in and to run in a race of continuous track or on a rail that acts as a guide. The track is mounted adjacent the jamb, one on each side of the door opening, vertically positioned to the height of the lintel of the door, then curving backward away from the opening at an incline or an angle to the horizontal, for a length sufficient to accomodate the door when the door is in its full open position.
The operator mechanism for the door is positioned overhead for example on or above the lintel, and includes drums, springs, cables, and a connecting rotatable shaft.
The shaft is mounted for rotation over the lintel with a cable collecting drum located at either end. Cable is wound around each drum, with one end attached to the drum and the other to the bottom most panel of the door. One or a plurality of tension springs are coaxially positioned over the shaft and are "wound up" so that when the door is positioned closed, the tension on the cables generates a continous force on the door slightly greater than the weight of the door. Typically doors 3 metres wide and 5 metres ~L

8~a~3 high made of wood with glass windows in one or all of the panels can weigh from between 300 kilograms to 5~0 kilograms. Doors of larger sizes, of course, weigh more.
These doors suffer from several major disadvantages.
They need regular inspection and adjustment. Where the door is operated by an electrically powered operator and a spring breaks the door usually remains operational until approximately 50% of the spring biasing force is dissipated by spring breakage. Thereupon, the door, either under its own weight, comes crashing down unexpected, or this results in an additional load placed on the electric motor and this causes operator cable skipping or motor stalling. If operator cable skipping takes place the up/down/on/off limit locations are lost and readjustment of the operator as well as spring replacement is necessary. Similar problems exist with manual operators, as those skilled in the art will attest.
The most common ailment however is that the door, while moving downward to close, ma~ hit an object in its path; the door tends to tilt in its tracks while the operator still rotates because of its momentum; the drums continue to play out cable. I'he cable becomes slack and jumps off one or both of the drums - "bird-nests".
Skilled maintenance crews must then be called in to reposition the door into its open position (by hand) so that the spring tensions are low and the jumped cable can then be rewound unto the drum. This ailment of bird nesting cable is acute in the temperate regions of North America where snow and ice accumulations take place at the base of the door opening. Snow buildup or accumulation prevents the door from fully closing properly. If the accumulation is ; not removed door tilting ensues then cable bird-nesting.

i~ -2-l i ~

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81~
Another species of vertically movable overhead door is the sectional vertical lift door. It is composed of a plurality of horizontally positioned panels each of which runs in its own vertically positioned track, located in a guide assembly mounted on either side of the door opening - and adjacent the jambs. One of the guide assemblies is also provided and contains a weight box with a plurality of weights, each independently connected by cables and pullies, one to each panel so as to act as counterweight to that panel. The length of the vertical travel of each counterweight is the same but in the opposite direction to that of its cooperating panel. Along the top and bottom of each panel i5 a catch rail which projects a lip into the path of travel of the adjacent panel catch rail and mates with it when they are in registry. A prime mover, geared - through a gear box, plays out or collects a control line - cable which has its end attached to the lowest panel.
; During door opening as the bottom most pannel rises to open the door it and the other rising panels cause their corresponding counterweights to correspondingly downwardly travel the same distance. The lower catch rail on a lower panel picks up the superadjacent panel when it passes into registry with the upper catch rail of the superadjacent panel. Thus the panels are lifted from the bottom to the top to ultimately nest adjacent one another at the top adjacent the lintel, when the door is in its open position.
The disadvantage to such door is the weight box and in particular the length of travel of the counterweight for the lowest panel, which must travel the whole distance of the opening. It is not uncommon, in large military and industrial applications, that this one counterweight alone weigh in excess of 1000 kilograms and travel in excess of 10 8~8 meters. Secondly, the door opens bottom first. That is, the bottom panel is positioned in registry with its superadjacent panel before the second most bottom panel begins to travel upward during the opening sequence.
Further large gaps exist between catch rails of the adjacent panels allowing wind to pass through the door and even causing, on occasion, severe rattling of the door panels.
Because both species of doors open from the bottom they both suffer from additional disadvantages. One is, that force can lift the door and open it even when the force is applied soley from outside; unless of course, the dead bolt lock associated with the door is positively secure.
Generally, it is forgotten to lock the door; hence, access into the building through the door is relatively easy just by lifting the bottom most panel from the outside.
Another disadvantage is with doors that incorporate prime movers with the operator. If strong (prevailing) winds are present and strike the door surfaces as it moves from its open to its close position the wind forces can be so strong that they force the door to bind in the tracks and hence the downward travel of the door is effectively stopped even though the operator continues to play out control line cable. When the wind subsides the lateral pressure of the door is relieved and the door falls freely until the cables are taut again (this is commonly known as "free fall" or "door free fall"). Needless to say damage to the door generally takes place; or, bird nesting, or, cable failure.
Free fall is very dangerous and is to be avoided.
I have discovered a novel door operator mechanism for use with both species of doors just described which;
(a) eliminates the need for torsion springs, drums, and cables in the operator. This eliminates bird , : : , 8~L~8 nesting and other ailments associated with that species of door;
(b) eliminates one counterweight in the vertical lift door.
In a further embodiment, cooperating with the control line of a vertically movable door is a paw which will constrain the door from travel and hence immobilize it whenever slack exists in the door operating control line.
This feature not only prohibits opening of a door from the outside irrespective of force used but inhibits door free fall.
The invention therefore contemplates an operator for a door which is composed of a plurality of panels which travel in th~ vertical and move between a lower closed position and . an upper open position, the improvement being an operator comprising:
: (a) a reversable prime mover including speed reduction means for moving the door in the vertical, .(b) a single tandum spool of two segments rotated by the reduction means, :~ (c) two control lines each being a longitudinally flexible member that flexes only in one plane orthogonal to the longitudinal axis of the member one end of each member connected to its own segment, the other end of each attached to each marginal side of the lowest panel of the door whereby rotation of the tandem spool by the prime mover in one direction winds the line on the spool and moves the door in one direction while rotation of the tandem spool in the other direction unwinds the line from the spool and moves the door in the opposite direction.

:

5 ' _5_ Preferably the control lines are roller chain, but spring steel metal ribbon is satisfactory.
In another embodiment, the invention contemplates in combination with a track, a pivoting paw for immobilizing a vertically movable door which moves between a lower closed position and an upper open position, the door guided to travel in a race of the track which is positioned on a lateral margin of the door jamb while the door moves relative thereto in response to the length of a control line having its free end attached to the lower portion of the door, the improvement comprising:
(a) a paw plate attached to and carried by the lower portion of the door;
~b) a pivoting paw, mounted to pivot on the paw plate, extending with a distal finger truncating at a filange;
(c) means for biasing the pivoting paw away from the paw plate and into mating engagement with the race and plate;
(d) means on said track for receiving said filange;
(e) means on the paw for attachment to the end of the control line whereby when the control line is taut, the paw is disposed into close proximity with the paw plate and out of engagement with the race and while the control line is slack, the paw is biased to place the filange into receiving engagement with the track.
The invention will now be described by way of example and reference to the following drawings in which:
Figures 1, 2 and 3 is a perspective view of a prior art sectional vertically movable overhead door.

8~8 Figures 4, 5 and 6 is a perspective view of the same door incorporating a door operating mechanism according to embodiments of this invention.
Figure 7 is an elevational view of the door of figures 4, 5 and 6.
Figures 8 and 9 are respectively sectional views along the tandem wheel of figure 7 showing the condition thereof when the door is closed, figure 8, and when open, figure 9.
Figures 10 and 11 are elevational views of another embodiment of door operating mechanism using an alternative control line such as a ribbon or metal band, figure 10 showing the condition when the door is in its open position and figure 11 when in the closed position.
Figures 12 and 13 respectively are sections along XII -XII and XIII - XIII of figures 10 and 11.
Figure 14 is a perspective view of a vertical lift door incorporating a door operating mechanism according to this invention. `
Figures 15 and 16 are cross sectional views along XV-XV
of the door panels of figure 14, shown in its closed position infigure 15, and along the same section line for an interim open position in figure 16.
Figure 17 is an elevation view of a portion of the weight box and lintle interface of the door of figure 14.
Figure 18 is a plan view along lines XVIII-XVIII of figure 17.
Figure 19 is a perspective of a security paw or device incorporating certain additional embodiments of the invention; the device typically attached to the lowest panel of a section of a vertically movable overhead door.
Figure 20 is a side elevational view of the securing device of figure 19.

., I ~, -~ 7 ``' iL1~81~8 Figures 21, 22, and 23 are explanatory elevational views of a door utilizing the paw of figures 19 and 20.
Figures 24, 25 and 26 are front elevational views of the paw illustrating its operative sequencesO
Figure 27 is a plan view of the security paw of figure 19 .
Figure 29 is an electrical diagram for controller operation.
Referring to the prior art and figures 1 through 3 a -: 10 sectionally vertically movable overhead door 30 includes a plurality of horizontal members 32 each of which is articulated with its adjacent panels by appropriately mounted laterally disposed hinges 34. The panels have at :
~ either side margin thereof a roller arrangement 35 with a :~ roller, 36 running in the race of a track generally indicated as 40. The roller arrangement 35 when disposed between adjacent panels typically includes integrally therewith, hinge 34; hence, is a hingeable roller arrangment ~
; 34'... The track 40 is located on either side of the door opening and has a vertical piece 41 which extends from the floor 25 to the upper limits (lintel) of the door opening then into a curved piece 42 and thence into a second straight piece 43 which is slightly inclined upward relative the horizontal so that when the door 30 is in its full open :
position (not shown in any of the drawings) the whole door is slightly inclined to the horizontal with the lowest panel thereof 32 L positioned essentially between the marginally positioned curved pieces 42.
Associated with door 30 is a door operator generally indicated as 46 which includes a horizontal rotatable shaft 47 having drums or spools 48 appended to each end. In the centre of the shaft 47 is a support bracket 49 which assists I L~ ;~ 8 , in carrying the shaft while securing the operator above the lintel. On each side of the support bracket is a torsion coil spring 51 which is coaxial with the shaft 47 and is tensioned, as those skilled in the art will know, in order to provide a rotating bias force on the shaft and spools.
Each of the spools have a cable, such as a wire cable 53, wound thereon, wherein one end of the cable, not shown, is affixed or attached to the surface of the spool 48 and the : other end extends down from the spool to attach itself, in a manner as those skilled in the art will know, to the margin of the lowest door panel 32 L.
In some applications the operator 46 is motor driven and this may be achieved by a reversable electric motor 55 connecting through a reduction gear box 56 that communicates motion through a sprocket and chain assembly 57 to one end of the rotatable shaft 47. In figure 1, such mechanism is ~ shown mounted on the wall above the door opening and lintel although any convenient location is satisfactory.
Careful perusal of figures 1 through 3 will indicate that in figure 1 initial impact of the bottom most margin Oe the lowest panel 32 L has taken place with a vehicle 60 attempting to pass through the door opening while the door was proceeding to close. In this instance, referring to figure 1, slack begins to take place in the cables 53 but to a greater extent in the left cable and about the spool 48L.
Referring to figure 2, since the operator 46 is still being activated (by the prime mover 55 or if no prime mover, by the momentum of the operator itself) the door remains still but further slack is played into the cables 53 as a result of the continued rotation of the shaft 47 and drums 48. The cables 53, having an inherent twist, tend to jump off the spools. Generally one cable succeeds to jump in advance of ~B' g 38~v~8 the o~her (left hand cable) and enwraps (53L) itself over the left most coil tension spring (51L). The operator eventually stops, as in figure 3, with the door 30 tilting and cable "bird-nesting" at 55 is complete.
Now referring to the invention, in figures 4 through 7, the operator 46 of the prior art is replaced with the door operating mechanism 70 incorporating the embodiments of the invention. The operating mechanism may be appropriately hung from the wall or it may be suspended and bolted unto a cross bar 72 which is attached to either side of the door frame above the lintel by, for example, vertical support members 74 attached to the wall. Referring to figure 7, the door operating mechanism 70 consists of a reversible prime mover 75 driving a shaft, not seen, of a gear box 76 (seen als~ in figure 21) which has at right angles to the drive shaf~ of the prime mover 75, a spool shaft 77 (more clearly seen in figures 7 through 11) onto which is mounted a tandum spool 78 having two segments 79; a left hand segment 79L and a right hand segment 79R. The segments are formed by the spool 78 having three parallel spacially disposed discs 80 coaxially mounted on the shaft 77. The spool 78 may be mounted unto the shaft 77 in any conventional means as those skilled in the art will readily know.
Two lengths of roller chain generally indicated as 81 are attached to the spool. A right chain 81R is attached to one segment of the spool 79R and one end from the other chain 81L to the other spool segment 79L. Each of the lengths of chain respective extend essentially horizontal to opposite side margins of the door 30 and are laced over rotatable idler sprockets or pulley 82 mounted on the cross beam 72 substantially as shown in figure 7. The chains 81 extend downwardly to terminate, preferably at the lowest 11~981C~8 side margins of the bottom door panel 32-L by the simple construction of a bolt affixing and terminating the chain to the door. In one embodiment, the chain terminates at the roller arrangment 35 but in a preferred embodiment on a guide wheel and paw mounting bracket 90, which carries a guide wheel 92 for the lowest panel 32-L that travels in the race of the track 40. (The paw mounting bracket 90 will be described in detail later and with reference to figures 19 and subsequent.) When the prime mover 75 is rotated in the one direction the spool 70 will rotate to collect each of the chains on its respective segment whereupon the door opens. In the open position each chain 81 is piled on its own segment substantially as shown at figure 9. When the prime mover is reversed, the spool rotates in the opposite direction playing out the chains and the door is lowered until closed (not shown in the figures) whereupon very little chain is piled on the spool essentially as shown in figure 8. The reason that the door will move up and down in response to the rotation of the spool is that the weight of the door causes a biasing force downward to be applied onto the terminal end of the chains 81 and hence tends to pull the door downward. The relative amount of piling of the chain on the spool will determine the precise location of the door~ Sprockets 82 engage the chain links in each roller chain 81, as those skilled in the art will now appreciate during chain travel. The door, therefore, is self indexing into relative position from closed to fully open depending upon the length of chain played out. The roller chain being flexible substantially only in one plane;
namely~ one of the planes which is orthogonal to the axis of links, (the longitudinal axis of the chain). The chain will flex therefore only through that orthogonal plane. That 81~8 plane is coincident or closely parallel to the discs 80 of the tandem spool 78 which control the length of the chain played out. There is no inherent twist in roller chain and hence when slack is played into the overall chain length, as for example when the bottom margin of the bottom most panel 32 L strikes an object 60 as in figure 5 (or the floor 25), the chain will flex and go slack and loops at 86 at its attachment end, with the door panel as shown in figure 5.
This will not cause the chain to jump the sprockets 82. The weight of the chain which depends from the tangent of the sprockets 82 vertically downwards tends to keep that portion of the roller chain (indicated as 81L' and 81R' in figure 7) and that disposed essentially horizontal between spool 78 and sprocket 82 reasonably taut. The chain flexes at 86 into the slack loop that assumes a position within the imaginary space defined by parallel planes or sheets, that are prolongations, vertically of the lines that respectively intersect each segment of the tandem spool and one of the sprockets. The chains are thus unable to escape the constraints between these imaginary sheets because of the combined effects of the adjacent discs 80 of the spool 78 which define the segments and the inherent structure of roller chain which allows flex substantially only in one plane; namely, that plane being one of the planes orthogonal to its longitudinal extent. These features result in interesting additional properties in the operation and function of the vertically moving door of figures 4 through 6.
Referring again to figures 4 through 6, in operation, assuming that the prime mover 75 has initiated closing of the door, at figure 4 the door strikes the hood of the vehicle 60. The operator continues to operate the door .~: .
~ -12-attempting to close the same but the door can no longer travel downward and rests on the damaged hood of the vehicle 60 notwithstanding the fact that the rotating spool 78 plays out more chain. This chain loops as at 86 at its distal ends, where it attaches to the guide wheel and latch mounting bracket 90 on to the lowest panel member 32-L. It is easy thereafter to stop the operator, by hand or by a trip bar (not clearly shown) mounted along the bottom margin of the lowest panel, and to reverse the prime mover thereby, whereupon counterrotating the spools to pick up the slack 86 in each chain, the chain becomes taut and the door begins to lift as at figure 6. It is impossible even if all the chain is played out, that the chain skip the idler sprockets 82 or bird-nest the pulley as with wire cable used in the prior art.
An alternative material to roller chain could be spring steel metal ribbon; or any other material which has flex in only one plane that is orthogonal to its longitudinal extent but no flex in the planes orthogonal to the flex plane. As such, thin metal ribbon could be used as the door attaching control lines and such an embodiment is disclosed in figures 10 through 13. The advantages of metal ribbon is that the piling up of each length of ribbon on its respective spool segment when the door is open is substantially less for a given door opening height than for roller chain, since roller chain has greater cross sectional thickness than metal ribbon.
On certain applictions it may be preferable to use -roller chain rather than metal ribbon. The advantage of metal ribbon is that since its thickness is less than roller chain the effective torque of the rotating spool on door ~8~8 lifting is more uniform throughout the whole travel of the door; on the otherhand, with roller chain higher torque exists during initial stages of door opening and because roller chain piles up faster on the spool, door opening speed increases with door travel with resulting decrease in the torque. Of course, high torque is not required to close an open door, but it is desired to open a closed door.
Referring to figure 14 the embodiments of the invention may also be applied to a sectional vertical lift door. In such application the door operating mechanism is mounted, preferably, at the top of that guide assembly 100 which also houses the weight box lOOW. The lowest most panel 132-L has its counterweight and associated cables removed so that there is no counterweight associated with panel 132-L. The magnitude of counterweights attached to each of the remaining panels (132-Ml etc. 132-U) may be left as is conventionally accepted in the present art or, if preferred, some weight may be added to each of other counterweights say approximately 2% to 5% thereof.
Each of the panels maintains its horizontal catch bar 170 & 175 at top and bottom for relative interlock with the adjacent panel as those skilled in the art will know. The door operating mechanism operates essentially as earlier described with the other door of figures 4 through 13. It consists of the prime mover 175 having its drive shaft driving the shaft of a reduction gear 176. The reduction gear box 176 has its shaft 177 protruding at right angles to the drive shaft of the prime mover and onto that shaft is mounted the tandem chain pick up spool 178. The spool 178, as well, has two segments 179; namely, 179R and 179L
respectively. These segments are likewise defined by parallel discs as depicted in figures 8, 9, 12 and 13. ~o ~ ,~
~ -14-81~8 lengths of roller chain are provided chain 181R extends from one segment of the spool 17~ down in close proximity to the weight box guide assembly 100 W to the top of the lower most panel 132-L and is affixed thereto by conventional means.
The left chain 181L extends from its segment across the top of the door opening to an idler pulley 182L and thence downward, in a similar way to the left end of the upper margin of the lowest panel member 132-L. The door panels are moved in the vertical by the prime mover 175 operating in either direction. Since all horizontal panels above the lowest 132-L are counterweighted with excess weight through their own counterweight cables C132 etc., when the prime mover 175 moves the lowest panel 132-L from its lowest position upward, as seen in figures 15 and 16, the counterweights of all the upper panels cause each of these panels to be moved in unison upward until they no longer can move. ~ence, the upper most panel 132-U migrates upward until it hits the lintel and s~ops its lower subjacent panel 132-M4 does the same etc. etc.(see figure 16 which shows an interim open position) until the door is fully opened (not shown).
There is advantage to this. Firstly there is the elimination of the counterweight from the lowest panel member 132 L which by far is the largest weight in crossection and the one that travels furthest. The size of the weight box is reduced; a set of counterweight cables and pullies eliminated. All counterweighted panels are biased to move upward because of over counterweighting each. Thus the operator locates the bottom most panel by the relative length in the control line or chain and all upper panels find there own relative position by the location and the catch bar of the lowest panel acting on the upper panels ~ -;38~8 through the media of the catch bars on each panel. The door when closed holds the panels relative to each other taut and there is no rattling of the panels in strong winds nor is there free space between the catch bars and panels when closed, which is a common phenomenon of present species ; doors when closed. Heat loss from the premisses is reduced.
Referring to figures 19 through 21 a securing device 90 especially adapted for use with the sectional vertically moveable overhead door of figures 4 through 13 is disclosed. ~ ~
The securing device 90 is a hingeable, biased operated ~ -moveable latch that indexes into the channel or track 40.
The latch 90 is integral to or replaces the lower roller arrangement 35. It includes a frame or plate 91 which carries a wheel or roller 92 adapted to run in the race of the channel 40. The wheel 92 rotates about its axle 93 which is mounted into and is carried by the plate 91 through~
support members 94 formed from the plate material. The frame or plate 91 has apertures through which wood screws or bolts 96 or the like extend so as to secure the paw 90 onto the inside surface of the lowest panel (32-L) near its lateral margin.
The plate 91 acts as an escutcheon for the axle 93 and extends at its lower extremity into an orthogonally positioned upright piece 97 which defines male fingers for a hinge 98 and 93. A pivoting paw member 100 includes ~
along its lower margin female fingers that mate with the male fingers to form the hinge 98 with the aid of a i retaining pin 99. The paw 100 extends upwards, at one end into a finger 105 and at the other end into a termination segment (bi-lateral joint) 106, which acts as the terminus - for the door attaching control line or roller chain 81. A

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coil spring 102 is positioned coaxial with the axle 93 between one of the support members 94 and the pivoting paw 100 to bias the paw 100 into the phantom position of figure 19. To achieve this the finger defines an aperature through which the axle 93 extends.
With this configuration, it will be seen therefore that if it will be seen therefore that if the control line is taut, the pivoting paw 100 assumes the vertical position, shown solid in figure 19, while if the control line is slack, the phantom position of that figure. The finger 105 has a filange tip that is beveled at 107 and extends as a step into a subjacently positioned receiving notch 109 for mating with each of a plurabilty serially disposed receiving recesses 41' formed the bed of the track 40.
In order to provide an essential universal joint at the terminus of the chain 81, the bilateral joint member 106 is disposed between the last link 81' of the chain 81 and the pivoting paw 100 in a manner that the joint member 106 is pinned to the last link 81' and relatively orthogonally to the paw 100. This causes the bilateral joint 106 to pivot in the plane of the paw 100. As will be seen from the drawings, with the aid of coil spring 102, the bilateral joint 106 pivots with the pivoting paw 100, through the same plane as a result of the hinge 98, eg. orthogonal to the plate 91.
The bilateral joint number 106 thus imparts a stress relieving flex to the chain terminus when the door is open and when the lowest panel is disposed between the curved tracks 42 located near the upper lintel of the door opening.
The lowest panel member when the door is the open position is moved out of that plane (the door plane) that is coincident with the vertical pieces 41 of the track 40.

!,.'.`1~. :
' e~ 17--~8~8 qhat defines the race (not shown clearly in figures 24 through 26 - but see it in figure 27 in which the rolling wheel 90 travels). By relieving the roller chain lateral stress greater life to the interface connection between the chain and the latch 90 is achieved. The bilateral joint member 106, is only beneficial for that purpose and does not truly affect the latching operation of the paw 100, which will now be described in greater detail.
Referring to figures 21 and 24, the door 30 may be moved up or down in response to the prime mover of figures 4 through 13. Since the door 30 has weight, tension is applied t~
the control lines or chains 81 and the paw 100 assumes the vertical position as in figures 24 and 19.
On closing, if the door strikes an ob~ect, pictorially illustrated in figure 22 by board B and the operator is still activated or moving, slack 86 builds into the chain, tension is relieved on the bilateral joint member 106, and the biasing spring 102 moves the pivoting paw 100 and finger 105 into the phantom positian of figure 19 as shown in figure 25. The finger tip 107 strikes the inside surface of the track 40. Now the track 40 not only defines the race but is provided with a plurality of finger accomodating recesses 41' spacially disposed at between 3 and 6 inches ` along the length of each vertical piece 41. If the object B
is now removed as at figure 23 the door 30 starts to fall (a~s per arrow) while the finger tip 107 runs along the race of the track until the filange of the finger indexes into the next lower accommodating recess 41', whereupon, under ; the biasing force of spring 102, it enters the recess 41' for engagement at the notch 109 and stops further fall of the door. The slack 86" in the chain is reduced somewhat (see figure 26).

81a~3 It will now be appreciated that a paw of this type is useful in stopping door free fall. It simultaneously will stop door lifting as long as sufficient slack 86" exists in the control line chain 81, so that the filange is biased by spring 102 to index into the accomodating slot 41'. This requires that the filange 107 extend through the track to beyond the outside surface margin 49 of the track 40 as seen figure 26. Thus the filange 107 must have a portion that extends out of the slot 41' when the finger 105 is biased into the phantom position of figure 19. Expressing this another way, the extent of the paw must be long enough that it traverses the plane of the race defined by the vertical - track 40.
Thus it will be appreciated that if the door is lifted, and the slack 86" exists, the filange 107 extending beyond the recess 41' inhibits upward movement of the door.
- Security is achieved.
It is but a simple means to ensure that when the door is in its full closed position that slack 86" always exists in the chain 81. Automatic latching is thus achieved.
Those skilled in the art will now appreciate that various variations of mechanical arrangements can be used to accomodate latching without deviating from this embodiment of my invention.
Referring to figure 29 the operator prime mover 75 if a ~C motor, may be connected to an AC/DC converter 301 and optionally to a battery pack 305. As such, the operator is operational even with electrical power failures and hence is suitable for military, hospital, fire, police and other emergency garage door installations.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An operator for a door which is composed of a plurality of panels which travel in the vertical and move between a lower close position and an upper open position, the improvement being an operator comprising:
(a) a reversible prime mover including speed reduction means for moving the door in the vertical, (b) a single tandem spool of two segments rotated by the reduction means, (c) two control lines each being a longitudinally flexible member that flexes only in one plane orthogonal to the longitudinal axis of the member one end of each member connected to its own segment, the other end of each attached to each marginal side of the lowest panel of the door whereby rotation of the tandum spool by the prime mover in one direction winds the line on the spool and moves the door in one direction while rotation of the tandem spool in the other direction unwinds the line from the spool and moves the door in the opposite direction.

2. The operator as claimed in claim 1 wherein the control line is a roller chain.

3. The operator as claimed in claim 1 wherein the control line is spring steel.

4. The operator as claimed in claim 1, 2, or 3 where the prime mover is a DC motor.

5. The operator as claimed in claim 2 including means for mounting the prime mover and spool above the door opening, sprockets rotatably mounted superadjacent lateral margins of the door opening, the roller chain, from each segment, travelling respectively over one sprocket, and means for attachment of each roller chain to its own lateral margin of a lower segment of the door.

6. The operator as claimed in claim 2 wherein the means for attachment of the roller chain to the lateral margin is through a bi-planar pivoting member with one plane of pivot in the plane of flex of the roller chain.

7. The operator as claimed in claim 6 wherein the plane of pivots of the bi-planar members are relatively orthogonal.