GB1604234A

GB1604234A - Apparatus for displacing a door or like closure member

Info

Publication number: GB1604234A
Application number: GB16332/77A
Authority: GB
Original assignee: TORBRIDGE INVESTMENTS Ltd
Current assignee: TORBRIDGE INVESTMENTS Ltd
Priority date: 1978-05-31
Filing date: 1978-05-31
Publication date: 1981-12-02

Description

(54) IMPROVEMENTS IN OR RELATING TO APPARATUS FOR DISPLACING A DOOR OR LIKE CLOSURE MEMBER (71) We, TORBRIDGE INVEST MENTS LIMITED, of 39/41 High Street, St. Peter Port, Guernsey, a Guernsey company, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: This invention relates to apparatus for displacing a door, window, lid or like closure member with respect to an opening that the door window, lid or the like closure member is required to be able to close or otherwise cover.

A particular application of the apparatus of the present invention is the opening and closing of garage doors without it being necessary for the driver of a vehicle manually to lift or otherwise handle the door.

According to the present invention there is provided apparatus for displacing a door, window, lid or like closure member with respect to an opening that the door, window, lid or like closure member is required to be able to close or otherwise cover, the apparatus including an electric motor, a drive connection between the door, window, lid or like closure member and the motor in which an element connectable to be moveable with the door, window, lid or like closure member is caused to travel along a rectilinear path relative to the mounting structure for the door, window, lid or like closure member; control means for controlling the operation of the motor, the control means including means responsive to a motor operation signal of a predetermined characteristic for producing a control signal to which the motor responds; and further control means so responsive to resistance to the closing movements of the door, window, lid or like closure member during any point of its travel between its fully open position and its fully closed position as to cause reversal of the drive of the motor whereby subsequent operation of the motor is in the sense necessary to return the door, window, lid or like closure member to its open position before the motor drive can be caused to effect a closing movement of the door, window, lid or like closure member, the response of the further control means being such as to respond to a predetermined level of resistance to movement of the door, window, lid or like closure member to reverse movement of the door, window, lid or like closure member, and also in the event of a jamming of the door, window, lid or like closure member against movement in the closing or opening direction to immobilise the motor.

Preferably the operation initiating signal is an optical signal, and the control means includes means so responsive to the optical signal that it is able to produce the control signal if the operation initiating signal when integrated over a predetermined time period attains a preselected signal level.

In the following description in relation to the drawings the various embodiments discussed have been concerned with the control of garage doors. However, it will be understood that the apparatus of the invention as disclosed in the various drawings is not restricted in its application to garage doors and could be used in relation to other forms of buildings and regions incorporating gates, doors, or the like.

Furthermore, it will be clear that the apparatus of the invention could likewise be used to displace articles other than doors.

Such articles include windows, shutters, lids etc.

For a better understanding of the invention and to show how the same may be carried in to effect reference will now be made to the accompanying drawings in which.-- Figure 1 schematically illustrates the general arrangement of apparatus of the invention as applied to a garage, Figure 2 is a perspective view of the reverse side of a garage door and a schematic representation of apparatus of the invention, Figure 3 is an exploded view of a first embodiment of a detail of the apparatus of the invention, Figure 4 is an exploded view of a second embodiment of said detail of the apparatus of the invention, Figure 5 is a cross-sectional view of the mechanical aspects of a combined drive and control unit used in the apparatus of the invention, Figure 6 is a block diagram of an electronic circuit used in the control unit, the Figure also showing very schematically the door operating apparatus, Figure 7 is a part sectional view to an enlarged size of an optical detector provided in the apparatus.

Figure 8 is a circuit diagram of the electronic circuit shown in Figure 6, Figure 9 schematically shows a modified form of the detail shown in Figures 3 and 4, Figure 10 schematically illustrates a further detail of the apparatus of the invention, Figure 11 is a schematic side view of a further form of the door control apparatus of the invention, Figure 12 is a schematic plan view of the apparatus of the invention applied to a sliding door, Figure 13 is a view of the apparatus of the invention as applied to a double sliding door structure, Figure 14A illustrates a door locking mechanism when a door is closed and locked, Figure 14B is a view similar to Figure 14A but with the locking mechanism unlocked, Figures 14C and 14D illustrate the locking mechanism of Figures 14A and 14B during movement of the door with which it is connected, Figure 15 schematically illustrates a further embodiment of the apparatus of the invention, Figure 16 is a slightly more detailed view of a portion of the apparatus shown in Figure 15, Figure 17 is a view to an enlarged scale of a detail of the apparatus of Figures 15 and 16, Figure 18 schematically illustrates a variation of the arrangement of Figures 15 to 17, Figure 18A is a view of a detail of Figure 18, Figure 19 illustrates an alternative mode by which the cable engages with a drive pulley, Figure 20 schematically illustrates an additional embodiment of the invention as seen from the side, Figure 21 is a schematic plan view of Figure 20, Figures 22 and 23 illustrate on a larger scale details of the embodiment of Figures 20 and 21, and Figure 24 is a part sectional view of a clutch arrangement.

Referring now to the drawings and more particularly to Figures 1, 2 and 3 of which Figure 1 very schematically illustrates a garage interior as including a door 1, a floor 2, a ceiling 3, and a rear wall 4. The door 1 is of the kind commonly known as an Up and Over door and for this reason is provided at each end of its top edge with support and guide wheels 5 which engage with guide tracks 6 (one being shown in Figure 1).

These tracks are supported at one end adjacent to the framing 7 of the door and at the other ends in brackets 8 suspended from the ceiling 3. The guide tracks 6 extend rearwardly and slightly downwardly in the direction from the door.

The door is provided with counter-balancing units 10, there being one such unit at each side edge of the door. The units each include a link 11 pivoted to the lower part of the door and also at a location intermediate of the length thereof to a support bracket 12 provided at a convenient location adjacent to the frame 7. The other end of the link is connected with a spring 14 which is attached by way of a screw type tension adjusting system (not shown in detail) to the frame 7 at a location adjacent the bottom thereof. The counter balancing is such that when the door is closed the springs 14 are under tension.

As so far described the door moves as follows On lifting the door outwardly and upwardly the wheels 5 move rearwardly along the tracks 6. The tensioning of the springs 14 acts in such direction as to assist this movement thereby counter balancing at least a part of the weight of the door. The amount of counter balancing is related to the stored energy of the springs 14.

Since the tracks are inclined rearwardly downwardly, the door, when it has been fully opened is positioned so that the top of the door is slightly above the level of the bottom of the door whereby the weight of the door holds the door in the open position.

On closing the door the door is pulled forwardly and downwardly. In this case the actual weight of the door assists in the re quired movements.

The door arrangement shown in Figures 1 and 2 is provided with a door opening and closing assembly 15 which enables the door to be opened and closed without it being necessary manually to handle the door.

The assembly 15 includes a threaded shaft or rod 16. The shaft 16 is connected at one end 17 to the top of the door at a location just below the top edge and at the centre of the width of the door. The other end 18 of the shaft 16 engages in a guide tube 19 which is carried at one end thereof in a combined drive and control unit 20 suspended by a support bracket unit 21 from the ceiling and at its other end by a support bracket 22.

The drive and control unit 20 incorporates an electric motor 23. This motor is of the series wound universal form working off the conventionally provided mains supply. The unit 20 also includes an associated control unit 24. The motor is in driving connection with the shaft 16, the driving connection being such that the shaft 16 is moved axially without rotation relative to the tubular member 19.

The control unit 24 is, as will be explained in detail hereinafter, responsive to an externally generated operating signal. A detector appropriate to the nature of the operating signal is provided. This detector is shown at 25 adjacent to the rear wall 4. The detector is a photocell which is responsive to light emitted from a vehicle 26, the light travelling along a predetermined path schematically shown at 27.

The shaft 16 carries stop members or contactor members 28 and 29 which are arranged to co-operate with switch contact arrangements (not shown in Figures 1 and 2).

The members 28 and 29 are so set that the control unit is able to stop motor drive after the door has been moved to the open or closed position.

The connection between the unit 20 and the supporting bracket 21 incorporates a pivotal connection which allows pivotal movement about a generally horizontal axis X-X which is transverse to the longitudinal axis of the shaft 16. As can be seen from Figure 3 the bracket 21 is carried from a support plate 30 which bridges a pair of rafters 31 of the garage structure.

One construction of the support bracket 21 is shown in Figure 3 and includes a vertical plate 32 which is connectable to the plate 30 by way of two angle pieces 33.

The control unit 24 is supported for pivotal movement about the axis X-X by pivots 34 engaging in brackets 35 secured to the plate 32. The bracket members 35 effectively combine to provide an inverted channel shaped support 36.

If desired, facility for pivotal movement in directions orthogonal to the axis X-X can be incorporated. Thus the two bracket members 35 can be replaced by a single channel shaped support which is mounted for pivotal movement about a vertical axis with respect to the remainder of the bracket structure 36. This connection can be of any convenient swivel type structure.

A second possibility for the additional pivoting is that the unit 24 can be mounted for movement with respect to an axis substantially parallel to the shaft axis.

This particular arrangement is shown in Figure 4 from which it will be seen that the channel bracket 36 is provided with eyelets 37 which can be pivotally connected by a pivot pin 38 to a U-shaped bracket 39 attached to the plate 32.

The construction and mode of operation of the drive and control unit 21 will now be considered. The unit 20 can be conveniently regarded as comprising two principal sections a mechanical section incorporating a motor drive and mechanical switch contacts and an electronics section for providing arrangements for inter-relating the various operational functions.

For convenience the motor drive and mechanical structure will be initially considered.

Referring now to Figure 5, the control unit 24 includes a housing 40 which is provided at each end with the pivots 34.

The housing also has a front panel 41 and a rear panel 42. The rear panel has an annular flange 43 connected thereto which supports the end of the tube 19 for the shaft 16, which latter passes through apertures provided in both of the panels 41, 42, the apertures being aligned.

A drive wheel assembly 44 is supported for rotation with respect to the housing by way of a thrust bearing unit 45 having a flange 45A by which it is mounted to the front panel so as to be concentric with the aperture therein. The assembly 44 includes a cup-like part 46 concentrically arranged with respect to the bearing unit 45 this part 46 defining a face plate to the outside of which a drive wheel 47 is secured and a recessed part for receiving a nut 48 which is operationally engaged with the screwed shaft 16 and which is secured to the part 46 by screws 49 which serve also to hold the wheel 47 in the desired position.

The motor 23 is mounted from the front panel 41 either externally or internally. In the Figure 5 external mounting is shown.

The position of the motor is such that its output shaft 50 is able to make driving contact with the annular periphery of the wheel 47, this periphery and/or the output shaft being provided with a suitable friction drive surface 51. It will thus be understood that whilst the motor 23 is in operation rotation of the output shaft will turn the wheel 49 and thus the nut 48. The rotation of the nut 48 will, since the control unit is fixed in position with respect to the plate 32 displace the shaft 16 axially of the drive wheel assembly and the nut 48.

The housing 40 as has been mentioned houses electronic components these are represented in Figure 5 as a printed circuit board 52 mounted from an annular support 53 which is itself mounted upon the rear panel 42. The board 52 and its support are suitably apertured to allow passage of the shaft 16 during its movements relative to the housing 46.

The printed circuit board incorporates an electronic circuitry which will be considered hereinafter and, in addition, is associated with a group of switch contacts. For convenience these contacts will be regarded as part of the mechanical structure.

A resilient contact arm assembly including contacts 54a and 54b extends from the printed circuit board 52. The contacts are normally open with the contact 54a running on the shaft, the latter being electrically earthed.

The contact 54a is positioned so that the free end thereof will be displaced by the contactor member 29 so as to be moved into electrical contact with the contact 54b during the shaft movement which takes place during the closure of the door.

The members 28 and 29 are positionally adjustable relative to the shaft and are lockable in a desired operational position by grub screws (not shown).

The length of the member 29 is such that once it has been moved to the position in which it closes the contacts 54a and 54b the member is able to maintain the contacts closed throughout the short period of shaft and door movements usually necessary to achieve a correct positioning of the closed door after the instant of actuation of the contacts 54a and 54b.

A second resilient contact arm 55 extends from the board 52 so as to be able to make operational contact with the outer surface 56 of the cup-like part 46. The surface 56 is covered with an electrically insulating material except for a short circumferential length. This arrangement is such that the contact arm 55 is able electrically to connect with the surface 56 once during each revolution of the wheel assembly and thus the nut 48.

The part 46 is electrically earthed so that when the arm 55 contacts the surface 56 the contact arm is effectively earthed.

A resilient contact arm 57 is positioned as to be operationally associated with tht contacter member 28 provided upon the shaft 16. Consequently when the shaft is in - predetermined position during its travel the member 28 earths the arm 57.

The control unit 20 includes a further switch which is responsive to the tilting of the housing 46 about the axis X-X.

This particular switch is schematically shown by a contact element 58 on the unit 24 and a contact 59 on the bracket 36. The purpose of this switch is to be able to switch off the motor drive in the event of any obstruction preventing movement of the door during door closure. The positions of the contacts 58, 59 are shown in Figure 9.

The particular conditions associated with the above mentioned contact arms and switches will be considered hereinafter.

Referring now to Figure 6 this is a block diagrammatic representation of the electronic circuitry provided in the unit 24 or associated therewith.

The circuit includes the detector unit 25 which is responsive to the externally generated signal. This detector can take various forms thus it could be a radio receiver unit, a sound responsive device, an optically responsive device, or other device depending upon the particular characteristic of the externally generated signal that is adopted for use with the system of the invention. In other words the detector is to be able to produce from the externally generated signal an output which is related to a selected characteristic of the external signal. As has been mentioned the apparatus or system of the invention involves as the external signal an optical effect and provides a photocell as the detector 25.

The electrical output from the photocell is delivered to a time -dependent signal integrating unit 60 which is intended to integrate said output over a preselected time period and produce a control signal if the integrated input satisfies predetermined criteria within a preselected time period. In the particular circuit envisaged the circuit is constituted by a diode pump circuit (to be considered in detail hereinafter). Output froro the unit 60 is coupled via an amplifier 61 to the unit 24 controlling operation of the motor 23 which drives the shaft 16.

The combination (shown in Figure 5) of the contact arm 55 and the rotating surface 56 acts as a pulse producing arrangement and as mentioned produces an output pulse for each revolution of the shaft and the nut 48. The output from the pulse producing arrangement is applied to a second time dependent signal integrating unit 63 which is also formed by a diode pump circuit and which is arranged to produce at its output a second control signal which after amplification by an amplifier 64 serves as a control input to the unit 24, and in particular serves to maintain the motor in operation for so long as the requisite pulse rate is maintained by the above mentioned pulse producing arrangement.

The signal line from the contact arm 55 to the integrating circuit 63 includes the switch operating arm 57 (Figure 5).

A second signal line, shown in dashed lines in Figure 6, connects with the unit 63 and includes the switch contact arms which are actuated by the contactor member 29 on the shaft 16. The two signal lines are also associated as will be considered in detail hereinafter with the door obstruction over-ride switch formed by the contacts 58 and 59. In the Figure the operation of the over-ride switch is indicated as diverting the output from the pulse producing arrangement from the second line which latter can conveniently be regarded at this stage as a door closing line to the first mentioned line which latter can conveniently be regarded at this stage as a door opening line.

At this point it is convenient to consider briefly the construction of the detector unit 25. The detector includes a photocell 65 located at the end of an opaque tube 66 having a light inlet orifice or aperture 67 of such dimensions that the light falling onto the sensitive area of the photocell has to be directed directly into the tube 66 i.e., along the path 27 of Figures 1 and 7. Photocell sensitivity is adjustable with respect to the input light by electrical methods to be considered hereinafter and by positionally adjusting the setting of the photocell lengthwise of the tube 66 thereby to allow more or less of the light responsive area of the photocell to be exposed to the incident light.

The control functions of the above described circuit are briefly as follows On energisation of the detector unit by signals appropriate to the particular form of detector unit the unit 25 produces an output signal. Since it is important that the system of the invention does not readily respond to spurious signals which could conceivably be such as to cause the detector to produce an output which is able to initiate door opening or closing the operational parameters of the integrating circuit are arranged that output signal from the detector has to be able to establish a predetermined signal level, amplitude or the like which once established is maintained over a preselectable minimum time period.In the present case it is arranged that the external initiating signals presented to the detector have to have a duration of at least three seconds and also be capable of establishing a predetermined signal amplitude within this time period. Hence, the system as a whole will not respond to spurious optical signals what ever their intensity unless the signals last for a time period exceeding three seconds (or what ever other time period may be chosen).

It will be appreciated that the correct operating signal can be established in a variety of ways i.e., one single long period light flash of the necessary intensity or a series of flashes of lesser intensity but whose integrated effect taken over the preselected time interval is sufficient.

In the event that the signal causing the activation of the detector satisfies the conditions for the output signal thereof to be able to cause the integrating circuit 60 to produce said first control signal the door opening will be initiated.

Following this initiation the motor 23 is started thereby turning the nut 48. As soon as the nut 48 rotates the contact arm 55 in conjunction with the surface 56 produces pulses which are delivered to the second integrating circuit 63. This second circuit is also time dependent and is so arranged that provided that the circuit 63 receives pulses at a rate which is above a preselectable minimum frequency it is able to produce the second control signal, which after amplification is able to maintain the motor 23 in operation.

In other words the circuit 63 essentially provides a HOLD system for a motor switching circuit.

When the door has been moved to the fully open position i.e., the member 28 has been moved by the shaft to the position in which it is able to diplace the contact 57 thereby to cut-off the first signal line from the integrating circuit 63 so that the latter no longer receives the pulses necessary to maintain the second control signal to the motor control unit 24 and thus the motor in operation. The motor is thus switched off.

As will be explained hereinafter the final action of the opening movement of the shaft 16 is to cause the reversal of the current supply to the motor so that when the motor is next energised it will rotate in the opposite direction so that the nut will move the shaft in the reverse direction so as to cause closure of the door.

In order to close the door the appropriate optical signal is delivered to the detector 25.

This will initiate the motor starting cycle and because of the above mentioned current reversal the shaft 16 moves the door towards the closed position. It will be understood that the contact arm 55 will be producing the pulses which ensure that the motor keeps operating.

When the door reaches the closed position the member 29 co-operates with the contact 54a as previously discussed whereupon the motor drive is stopped, and in addition the current supply to the motor is once again reversed so that when the motor is next energised it rotates in the direction re lated to door opening.

In the event that the door during its closure movement meets with an obstruction the forces produced in the shaft 16 will produce a tilting of the unit 24 relative to the bracket 26 so that the over-ride switch contacts 58, 59 are closed. This action resulting in the immediate reversal of motor drive so that the door is reopened. The obstruction over-ride switch effectively provides a changeover switch which on operation diverts the pulses from the second to the first pulse line so that the pulses are still applied to the circuit 63 thereby maintaining motor drive.

In the above discussions the detector circuit has been shown as being located adjacent the rear wall 4 of the garage. This position requires that a window be provided in the door 1, in the door frame 7 or at a location adjacent the door. In Figure 2 the window is schematically shown by the rectangle at the bottom right corner of the door.

An advantage of this arrangement is that the same detector unit can be used for both opening and closing the door irrespective of whether or not the vehicle is inside or outside the garage.

An alternative arrangement is to provide a first detector (not shown) in the jam of the door and a second detector at the rear of the garage. With this arrangement the first detector is actuated when the vehicle is outside the garage and the second is actuated when the vehicle is inside the garage.

A detailed circuit of the control unit will now be considered in relation to Figure 8.

In the consideration of Figure 8 those components which have previously been identified in relation to previous Figures will be referred to by the same references.

The circuit of Figure 8 includes mains supply terminals 70 and 71. The primary winding of a low voltage insulating transformer 72 is connected across the terminals 70, 71.

Also a circuit including a lamp 73 and a relay operated switch 74 having a movable contact 74a and a fixed contact 74b are included in a series circuit connected across the terminals 70, 71. A manually operable switch 74A is connected in parallel with the relay operated switch 74.

The armature of the motor 23 is included in a circuit which is connected across the terminals 70, 71, this particular circuit including a first switch 75, a series connected resistor 76, a reversing switch arrangement 77 and a second resistor 78.

The reversing switch arrangement 77 includes a first contact set 79 comprising a movable contact 79a and fixed contacts 79b and 79c. The arrangement 77 also includes a second contact set 80 including a movable contact 80a and fixed contacts 80b and 80c.

The movable contacts 74a, 79a and 80a are ganged and are actuated by their associated relay 81. The switch 75 is likewise actuated by its associated relay 82.

The secondary winding of the transformer is coupled via a diode 84 and a capacitor 85 across a positive voltage rail 86 and a negative voltage rail 86A which is earthed.

An external signal detector circuit which can be regarded as being located adjacent to the door 1 is connected between the rails 86 and 86A and includes a photocell 65 connected in series with a light emitting diode 88 and a variable resistor 89. A normally open manually operable switch 90 and associated series resistor 91 are connected in parallel with the photocell 87.

The output of the detector circuit 25 is applied to the input of the integrating circuit 60. This circuit is a diode pump circuit including capacitors 92 and 93 and diodes 94 and 95.

A second detector circuit 25A is connected between the voltage rails 86 and 86A and includes a photocell 65A connected in series with a light emitting diode 88A and a variable resistor 89A. The output of the detector circuit 25A is applied to the input of an integrating circuit 60A which comprises capacitors 92A and 93A and diodes 94A and 95A.

The operational sensitivities of the two photocells are set by suitable adjustment of the associated variable resistors 89 and 89A using the associated light emitting diodes as indication means during the adjustment process.

The two diode pump circuits 60 and 60A each discharge into a Darlington type circuit including transistors 96 and 97, by way of a base resistor 98. The Darlington circuit has a common emitter resistor 99.

In order to ensure that any residual charge on the circuits 60 and 60a can be discharged a resistor 100 connects their joint output line which connects to the resistor 98 with the earthed voltage rail 86A.

The collector load circuit of the transistors 96 and 97 includes two principal sections 101 and 102. The section 101 incorporates the relay 82 and its associated discharge diode 103 and a capacitor 104 and variable resistor 105.

The second section incorporates a series circuit including a diode 106, a variable resistor 107, and a relay 81 with its associated discharge diode 108. A micro switch 109 having normally closed contacts 109a, 109b is included in the energising current line to the relay 81.

This microswitch 109 is located within the housing 40 and its actual contacts 109a and 109b are housed within the body of the switch. Thus for convenience the operating member for the switch 109 is represented by the contact 57 in the drawings and the movable contact by the contact 58 provided on the bracket 36. Thus to all intents and purposes the closing of the contacts 57, 58 is essentially in electrical terms equivalent to the associated operation produced upon the microswitch contacts 109a and 109b.

In practice, the contact 58 comprises a plate (not shown) which is able operationally to co-operate with the contact 57. The plate is positionally adjustable with respect to the bracket 37 to allow preselection of the angle between the unit 24 and the bracket 37, that is the vertical, at which the contacts co-operate to operate the microswitch 109.

It will be appreciated that other arrangements can be used for utilising the relative tilting of the unit 24 to the vertical as a means of operating or switching an electrical circuit. Furthermore, it will be understood that the microswitch could be located between the bracket and the base of the plate 32.

If desired two microswitches could be provided so that tilt in either direction to the vertical can be used for switching purposes.

The contact 55 and the part 46 providing Whe pulse generating circuit is connected across the voltage rails 86 and 86A and includes a resistor 110 in series with the contactor switch which is associated with the contact 55 and the surface 56 of the part 46.

The junction of the resistor 110 and the contact 55a is connected via a resistor 111 to the input of the second integrating circuit 63 namely the second diode pump circuit, the latter including diodes 112, 113 and capacitors 114, 115. The output of the second diode pump circuit 63 is connected through a resistor 116 to the base of a transistor 117 whose collector circuit connects with the junction of the Darlington circuit output and the diode 106. A resistor 118 connected across the second diode pump circuit output serves completely to discharge any residual voltages in the circuit 63 so that transistor 117 is not switched on. The emitter circuit of the transistor 117 includes a diode 118.

It will be noted that the collector circuit of the transistor 117 effectively comprises the sections 101 and 102 of the collector load circuit of the Darlington pair 96, 97 and is thus identical thereto.

A diode 120 is connected between the base of the transistor 117 and the contact 109b of the microswitch 109. This connection includes the contact 57A. Thus the contacts 57 and 28 can be considered to form a switch 121. The contacts 54a and 54b combine to provide a switch 122 connected across the output of the diode pump circuit 63 and the voltage rail 86A.

A safety circuit which is responsive to motor temperature for monitoring the temperature of the motor. This circuit can take many forms. However that shown in the Figure 8 includes a thermister 123 connected between the voltage rail 86 through a variable resistor 124. The junction of the thermistor and the resistor is connected through a diode 125 to the base of a transistor 126 having its collector circuit in the load circuit of the Darlington pair 96, 97. The triggering temperature of the thermistor is set by the resistor 124. In operation, if the motor over heats, for example, due to frequent operation of the door operating system within a short time period the thermistor triggers and as a result the transistor 126 is switched off thereby causing the de-energisation of the relay 82 and thus the switching off of the motor.

The door opening and closing system as so far considered in relation to Figures 1 to 8 operates as follows. For convenience of description it will be presumed that the two detector circuits 25 and 25A have been previously set for optimum operation, and that the associated diode pump circuits 60 and 60A together with the circuit 63 have likewise been adjusted to provide the required performance criteria.

The vehicle 26 is driven to a predetermined position with respect to the detector 25 so that on directing a beam of light or a preselected number of flashes of light towards the detector the light is able to impinge upon the orifice 67 of the detector tube 66 and thus travel to the light sensitive region of the associated photocell 65. As has been previously mentioned this photocell is mounted in the tube so that ambient light modulated or otherwise or random flashes cannot substantially affect the resistance of the photocell 65.

On directing the vehicle headlight beam onto the photocell 65 the resistance of the latter changes and produces a potential across the resistor 89. This develops a charge on the capacitor 93. Provided that the rate at which this charge increases exceeds the rate of discharge across the resistor 100 a potential will be developed at the base of the transistor 96 which is sufficient to trigger the Darlington circuit into conduction thereby to energise the relay 82.

Although the diode pump output is also applied to the said second section 102 the latter is not operated in view of the additional resistance levels in the section namely the inclusion of the resistor 107. On energisation of the relay 82 the contacts 75a, 75b in the motor armature circuit are closed whereupon the motor starts and thereby rotates the nut 48 which in turn produces the axial displacement of the shaft 16 and thus the door 1.

At this initial stage of operation the switch associated with the contacts 54a and 54b has been closed since the contact 54a is moved away from its normal position to contact the contact 54b which is thus earthed. As a result the base of the transistor 117 is effectively grounded at this instant.

Meanwhile, the switching on of the motor 23 displaces the shaft so that the contactor element 29 allows the contact 54a to break contact with the contact 54b. At the same time rotation of the motor causes the contact arm 55 so to co-operate with the surface 56 of the part 46 that a series of pulses are delivered to the second diode pump circuit by way of the resistor 111. Provided that the pulses are delivered at the correct rate and assuming that the shaft movement is unimpeded the pulses will be at the correct rate the diode pump circuit 63 is able to produce the requisite output signal. The time period of the second pump circuit is very much shorter than that of the circuit 60 and is, for example, 0.1 of a second.

In other words the normal operation of the shaft drive is such that the pulses are produced at the required rate so that the capacitor 115 charges at a rate faster than it is able to discharge through the resistor 118. Consequently, the pump circuit 63 will produce an output which will maintain the relay 82 in the energised state.

It will be understood that following the cessation of the light signal to the photocell 65 the first diode pump circuit 60 will not be receiving input so that the transistors 96, 97 will rapidly discharge the capacitor 92 whereby these transistors are turned-off. Hence from this point of time the relay 82 is maintained in the energised state solely by the production of the pulses by the co-operation of the contact arm 55 with the part 46.

As has been briefly mentioned within a short distance of the start of the shaft displacement the contactor member 29 moves away from the position in which it holds the contact 54a and 54b in electrical contact thereby enabling the transistor 117 to switch on immediately by reason of the charge developed across the capacitor 115 and thus, as previously stated, become the sole source of current for the relay 82. The relay 81 will not become energised because of the voltage drop across the resistor 107.

If the movement of the door is for any reason obstructed it follows that the movement of the shaft 16 will be constrained against further axial movement, whereupon further rotation of the nut is prevented since the threaded engagement will cause the nut to lock on the shaft. Consequently, the pulse production will cease so that a charge on th capacitor 115 cannot be maintained whereby the transistor will cease conducting. Since the relay 82 is energised solely by the potentials developed from the pulses the relay is no longer energised and therefore drops-off and switch 75 opens thereby stopping the motor.

On the other hand it is presumed that no obstructions arise the door will continue to move towards the open position at which the actuator member 28 is able to co-operate with the switch contact arm 57 and in so doing operates the associated switch 121 whereby the diode 120 is effectively connected to the earthed rail 86A. The base of the transistor 117 is now effectively earthed by the now forwardly biassed diode 120 and is therefore switched off. This condition allows the capacitor 115 to discharge so that the relay 82 becomes de-energised whereby the switch 75 is opened to stop the motor 23.

A further consequence of the operation of the switch 121 (that associated with the contact arm 57) is that the relay 81 is effectively directly connected between the voltage rails 86 and 86A and therefore receives the full energising current since the resistor 107 is not effectively bypassed. The relay 81 now operates and operates the change-over switch 77 thereby reversing the applied current to the motor 23 whereupon it is caused to rotate in the reverse direction. In addition the switch 74 is closed to switch on the light 73.

Since the relay 81 operates effectively instantaneously, and since the instant of deenergisation of the relay 82 is effectively delayed by the time required to discharge the capacitors 104 and 115 the relay 81 is able to energise before the relay 82 deenergises.

In other words a differential switching of the relays 81 and 82 takes place. In practice, this reversal of motor drive thus takes place before motor switch-off thereby producing a braking action on the motor and in consequence upon the drive to the shaft 16 and door movement. It will be understood that the time differential can be adjusted for optimum braking effect by adjustment of the resistor 105.

The above mentioned braking action assists in off-setting the inertia of the door.

From the foregoing it will be appreciated that at this stage the door will be opened and the motor drive direction set ready for subsequent reclosure.

To close the door 1 the vehicle lamps 68 are flashed so as to provide the appropriate optical signal to initiate operation of the detector 25 if a single detector is used or a detector 25A if the double detector arrangement is being employed.

If desired the closure could be initiated by momentarily depressing the switch 90.

Following either of the above mentioned signal initiating actions the above described circuit responds by triggering the Darlington connected transistors 96 and 97 so that they conduct to energise the relay 82 and thus switch on the motor 23 and start the movement of the shaft 16.

Since the drive is now in the reverse mode the shaft is moved in the door closing direction.

Shortly after the commencement of the shaft displacement the member 28 is disengaged from co-operation with the arm 57A, thereby removing the full energising current from the relay 81. Meanwhile, since pulses are being produced by the contactor 55 and these cause the second diode pump circuit 63 to trigger the transistor 117 into conduction i.e., the condition that holds the relay 82 in the energised state and the motor switched on.

In addition, the triggering of the transistor 117 maintains a reduced level of current at the relay 81 which is sufficient to maintain this relay 81 in the energised condition. The relay 81 is retained in the energised state before the relay can become de-energised as a result of the movement of the member 28 from its contact with the arm 57A. Hence the reversing switch 77 is prevented from re-operating and the motor continues its motion in the door closing direction.

Assuming that there are no obstructions to the door closure movement the door will be able completely to close. At this door closure position the member 29 once again displaces the contact 54a into contact with the contact 54b. As a result the base of the transistor 117 is earthed and is thus turned off so that the holding circuits for both relays are effectively removed.

However, bearing in mind that the relay 81 has been maintained by the application of a reduced level current during the period of door closure as compared with that applied to the relay 82 the relay 81 is able to de energise faster than the relay 82. Consequently, the reversing switch is operated by the change of state of the relay 81 to return the motor drive direction to the door opening direction shortly (a fraction of a second) the relay 82 de-energises and switches off the motor 23.

Hence since the motor drive has reversed before it is stopped the period of reverse drive introduces a braking effect similar to the one previously described.

From the foregoing it will be noted that at this stage the door is closed and the motor is set for drive in the door opening direction.

In the event of any obstruction which is able to prevent or at least retard the displacement of the shaft the rate of pulse production will decrease below the level necessary to ensure that the second diode pump circuit 63 produces an output sufficient to maintain the transistor 117 fully conductive.

Because of the inclusion of the resistor 107 in the energising circuit of the relay 81 and the capacitor 104 in the circuit of the relay 82 and collector load current is not sufficient to hold the relay 81 ON so that it de-energises to allow the reversing switch 77 to change-over. Consequently, as has been explained hereinbefore the motor drive is reversed so that it automatically returns the door to the open position.

If the obstruction is of such nature that the door cannot move in either direction or the motor is not capable of being accelerated fast enough after direction reversal due, e.g., to a heavy door, the rate of production of said pulses falls below the rate necessary to sustain the output from the second diode pump circuit 63 so that the transistor 117 is able to switch off thereby enabling the relay 82 to de-energise and thereby switch off the motor.

Under these post obstruction stopping conditions if the door is stuck in a mid-open position (whether or not the door is being opened or closed) it is possible to attempt to reactivate the system by reflashing the vehicle lights or to actuate the switch 90.

This action will normally result, provided that there is no continuing physical obstruction to door movement and the electronic circuitry is functioning correctly, in the door being opened, and never closed.

In this connection it should be noted that it requires a switching contact between the arm 57 and the member 28 to achieve the setting of the reversing switch 77 to the motor drive direction required for door closure.

If during the door opening cycle the cooperation between the contact arm 57 and the actuator member 28 fails to stop the motor drive so that the shaft continues to pull the door in the opening direction the member 28 will ultimately be pressed against the housing 40 and in so doing will lock the shaft against any further movement. This as previously mentioned prevents the required production of said pulses so that the motor is automatically stopped by the de-energisation of the relay. Hence the actuator can be additionally regarded as providing a fail-safe mechanical over-ride facility in the event of the member 28 not producing the intended result.

The function of the switch 109 i.e., that formed by the contacts 57, 58 will be considered in more detail.

As has been indicated in the event of obstruction during door closure the drive to the motor is reversed automatically to reopen the door. When the door is at the nearly closed position the shaft 16 sags under the combined effect of its own weight and the pushing effect of the motor 23. If an obstruction should occur at this nearly closed position thz obstruction will aggravate the shaft deflection. The pivotal mounting of the unit 24 enables a predetermined limited amount of this sagging to be accommodated this limited amount being such as to enable the shaft to maintain alignment with the housing bearings 45, 43 and 19. If the amount of tilt should exceed this predetermined limited amount of tilt the unit 24 will be tilted to such extent that the contacts 57 and 58 are operated. The operation actuates the microswitch 109 to open the contacts 109a and 109b.As a result the relay is deenergised causing reversal of the motor drive as has been previously discussed.

In the event that the switch 122 fails to operate the tilting effect will occur and the switch 109 is actuated thereby causing the reversal of motor drive to the door opening direction.

Furthermore, in the event of operational failure of both switches 109 and 122 the extended travel of the shaft will cause the actuator member 28 to lock against the nut 48 thereby stopping its rotation and thus the production of the pulses which are necessary to maintain the motor drive relay 82 energised so that the motor will be stopped.

In the foregoing the use of two photocells has been discussed in relation to the operation thereof by the same vehicle. In the case of a two car garage with a common door one of the detectors would be associated with one side of the garage and the other detector with the other side of the garage so that the door could be opened what ever side of the garage is being used. If desired additional photocells could be used for door closure and opening when the vehicle is inside the garage.

Any such additional photocells and associated diode pump circuits can be readily incorporated into the circmt of Figure 8 at the same location as the incorporation of the diode pump circuit 60A.

A switch 74A is conveniently provided in parallel with the switch 74 to allow the light 73 to be switched ON independently of the remainder of the door control system.

The above mentioned protection circuit including the thermistor 123 operates as follows.

On overheating of the motor as a result, for example, of rapid cyclic succession of opening and closing the door the resistance of the thermistor reduces so that the voltage on the base of the transistor 126 is correspond ingly altered in such sense as to reduce current flow in the collector emitter circuit thereof.

At a set level of the thermistor resistance which is presettable by means of the variable resistor 124 the current in the collector emitter circuit of transmission 126 can not sustain the relay 82 so that it de-energises and switches off the motor. Following said switching off of the motor the door opening system cannot be reoperated until the temperature of the motor falls.

Other forms of temperature responsive devices could be used in place of the thermistor. For example, a bi-metallic strip could be used. In this case the transistor 126, the resistor 124 and the diode 125 would be omitted since the bi-metalic strips provides an ON/OFF switch in the energising circuit of the relay 82.

In an alternative mode of suspending the combined drive and control unit 20 shown in Figure 9 the bracket 36 is so mounted to the plate 32 that it is displaceable in the longitudinal direction of the shaft with respect to the plate 32. As shown the unit is connected to the plate 32 by bolts 128 which engage in a slot 129. The bracket is preloaded to a central setting of the slot by springs (not shown) which are able to hold the unit stationary relative to the plate for normal level forces arising during opening and closing of the door, but which on the occurence of an obstruction allow relative movement between the bracket 26 and the plate 32. Switches 130, 131 are provided at suitable positions as to be able to respond when such relative movement occurs. The operation of these switches serving to initiate control functions such as have been previously discussed.For example, the action of the switch 109 which in the Figure 9 involves the external operating contacts 58 and in this case two of the contacts 57 in view of a di-directional operation requirement.

As an alternative of the use of a contactor arm 55 electrically co-operable with the surface 56 of the part 46 a centrifugal switch (not shown) can be employed. This switch can be normally open and arranged so that when the shaft is rotating at the correct speed the switch is closed to maintain in put to the input of the transistor 117.

In the event that the movement of the door is obstructed it has been indicated that the shaft is constrained against rotation and in so doing stops rotation of the nut and thus the drive wheel assembly 44. However, the motor output shaft 50 will still be rotating at the same speed. The resulting speed difference is either accommodated by slip between the shaft 50 and the friction drive surface 51, or a speed sensitive clutch arrangement can be incorporated in the drive.

The driving contact between the motor drive shaft 50 and the wheel 47 can be resiliently loaded. To achieve this the motor is displaceably mounted from a support connected with the housing 24 and is resiliently loaded towards the wheel 47 by a spring arrangement connected to the motor and with the housing by way of a manually adjustable adjuster unit. The above arrangement of the resilient loading has the benefit of defining to a great extent the power transmitted to the wheel from the motor shaft before slipping occurs. In addition, the arrangement is useful in the event of door obstruction where reversal of the movement of the door is desired expeditiously and within a minimum load exerted upon the obstructing force (which may be a child) reversal being a result of reducing wheel speed so as to de-energise the relay 81.

The provision of the adjuster unit allows a particular construction of the apparatus of the invention to be able to control the movement of a wide variety of door sizes and weights, allows wear between motor shaft and the nut 48 to be accommodated, and also enables small imperfections in concentricity of these elements to be accommodated.

In a variation of the drive between the motor shaft and the wheel gear or belt drives can be used.

If it is thought desirable to provide a facility of variable speed drive of the motor a silicon controlled rectifier or Triac type speed control system can be used.

Conveniently, the speed control arrangements can be introduced in series with the switch 75 and the resistor 76.

Referring now to Figure 10 this schematically illustrates an arrangement for disconnecting the end 17 of the shaft from the door in the event of a power failure or breakdown of the door operating system.

Two brackets 132 are secured to the door 1 and the end 17 is connected to the brackets by a pin 133.

A link 136 is connected at its lower end to a lever arm 137 provided on a bar 138 which is coupled to rotate with the con ventionally provided door locking handle 139.

The upper end of the link connects with a cord or cable 140 passing over a pulley 141 and connecting with the pin 133.

To release the shaft end 17 it is merely necessary to turn the handle 139 in the direction of the arrow. The turning movement pulls the link 136 downwards and in so doing extracts the pin 133. As soon as the pin is removed the unsupported end of the shaft 16 will fall away from the brackets but will be restrained from falling onto the car by the casing 40 abutting the bracket 36.

However the end of the bar will fall far enough to allow the door to be opened without being obstructed by the shaft.

Figure 11 illustrates a further construction in which the shaft is positionally fixed. That is the shaft neither rotates nor axially displaces.

In this construction one end of the shaft is secured by a support bracket to the lintel of the door frame 7 and the other shaft end is carried by a bracket 143. The combined drive and control unit 20 is engaged upon the shaft and is basically similar in construction to the previously discussed units 20. In the present arrangement the unit itself travels lengthwise of the shaft 16. The support bracket 36 to which the unit 24 is pivotted is effectively inverted and is provided with an arm 144 which is pivotally connected with the top of the door 1. The door and its associated guides 6 and counterbalance units are as previously described.

The previously mentioned contactor members 28 and 29 are similarly provided upon the shaft.

It should be noted that as the pivotal axis of the unit 24 relative to the bracket 36 passes through the axis of the shaft no undesirable force couples arise from the thrust on the system arising door opening and closing.

So far the control system of the invention has been considered in relation to the Up and-Over form of door. If desired the system of the invention can be used with sliding doors, and doors hinged to the door frame.

Such doors can be single or double doors.

Referring now to Figure 12 this schemati cally illustrates a sliding door 145. As can be seen the shaft 16 is mounted between two support brackets 146, 147 such that the shaft is positionally and non-rotatably mounted so as to be parallel to the guide rail 148 for the door.

A combined drive and control unit 20 incorporating the components previously discussed is engaged by the shaft 16. The unit 20 is mounted at a convenient place directly to the door the position being selected so that the required amount of opening is possible. The single or double pivotting features can be incorporated if thought or found necessary.

An alternative drive system for use with a double sliding door arrangement is shown in Figure 13. In this Figure the doors 149, 150 will be supported from the conventionally used forms of guide rails (not shown). In this case the combined drive and control unit 20 includes two shaft drive nuts (not shown) driven via a gear arrangement from a common output shaft of the motor. As can be seen from Figure 13 the unit is supported from the garage ceiling 3 and the shafts 16A and 16B are carried on the doors.

With this arrangement the drive to the two shafts 16A and 16B is such that the doors always move in opposite directions to each other. This is readily achieved by the gear drive.

In a further modification of the circuitry provided for the control of the doors an optical transmitter can be provided for producing the external signals. The transmitter incorporates a light source which is modulated at a convenient frequency e.g., 1 Khz. The detector 25 is provided with a suitable demodulator circuit which enables the photocell output to be fed to the associated diode pump circuit only on receipt of the correct modulating frequency.

A burglar alarm system can be incorporated.

This can include a timing circuit which is selectively adjustable and which produces an alarm signal unless the timing circuit is inhibited within a presettable time period.

An inhibiting switch is provided for this purpose. In practice, this switch would be sited in such manner that its location or mode of operation is known to nominated persons only.

The door opening and closing arrangements so far described basically rely upon the shaft 16 and its engagement with the unit 24 to hold the door closed.

If it is desired or required to provide a positive locking of the door in addition to the shaft/unit interconnection a separate locking unit can be provided.

The locking unit can be, for example, an electromagnetic type lock. The lock is energised when the door control system is set to door closing and released when the door opening cycle is initiated.

A mechanical form of door locking device is shown in Figures 14A to 14D.

The device includes a latch member 156 pivotally connected to the lintel of the door frame, the latch member being resiliently loaded by a spring 156A to the position shown in the Figures 14A to 14B.

A suitably shaped bolt or detent member 157 is mounted for vertical movement relative to a guide element 158 which is pivotally carried at the end 17 of the shaft 16 of the door opening system. The bolt 157 is provided with guide pins 159 which engage in slots, provided one to each side of the element 158. The element 158 is resiliently loaded by springs 160 to a retracted position in which it is free from the latch member 156. The pivotal connection between the guide element 158 and the shaft end allows the end 17 to be retracted with respect to the bolt as the door opening cycle commences to allow the springs 160 to retract the bolt and thus release the latching effect.The end of the shaft 16 and the bottom of the bolt are provided with co-planar guide or cam surfaces 162 and 163 respectively which enable the final closing movements of the shaft to displace the bolt to the locking position.

The pivotal connection between the guide element 158 and the end 17 of the shaft is able readily to accommodate the progressive positional changes of the door relative to the shaft during the opening or closing cycles.

In the Figures, the Figure 14A illustrates the relative positioning of the shaft end 17, the guide unit 158 and the bolt 157 when in the locked or latched position.

Figure 14B illustrates the door closed and bolt unlatched relative positioning.

Figure 14C illustrates the relative positioning between the guide element 158 and the shaft 16 during an intermediate stage of the door movements.

The relative positions of the guide element and the shaft when the door is fully open is shown in Figure 14D.

It will be clear that during the closure of the door the guide element will be progressively returned from the Figure 14D setting to that shown in Figure 14A as the door is returned to the closed position. In attaining this position the bolt forces up the latch member 156, the latter returning to its initial position under the action of the spring 156A.

The various door opening and closing arrangements so far considered have related to systems involving a threaded shaft or the like.

It is possible to replace such shafts or the like by alternative arrangements such as fixed guide wires, cables chains or similar means, or movable wires, cables chains or similar means.

Figures 15 to 17 schematically illustrate a control system, for an Up and Over form of door, employing an endless cable.

In the consideration of the construction and operation of the system of Figures 15 to 17 and any subsequent Figures those components which have a function similar to components involved in relation to control systems employing shafts will be identified by the same reference numerals.

Referring now to Figures 15 to 17 an endless cable 164 having upper and lower cable runs 164A and 164B is carried by two pulleys 165 and 166. The first pulley 165 is mounted in a pulley support secured to the lintel of the door frame 7. The pulley 166 is either mounted upon the output shaft 50 of the motor or otherwise driven therefrom. For convenience the pulley is shown on the shaft 50.

The door 1 is mounted in the manner previously described in relation to Figures 1 and 2.

A bracket 167 is pivotally connected at one end to a bracket 168 located at the top edge of the door and at a centrally located position. The other end of the bracket 167 is pivotally connected to the cable lower run 164A. A cable tensioning unit 169 (shown as a spring) is provided for the cable. This tensioning unit can either be actually included in the length of the cable or associated with a pulley arranged to co-operate with the cable.

As so far described rotation of the motor rotates the pulley 166 and thus drive the cable. As shown in Figure 15 if the motor rotation is such that the lower cable run travels from left to right the door is opened, whilst rotation in the reverse direction returns the door to the closed position.

The motor 23 is associated with a combined drive and control unit 20 similar to that previously discussed. The cable runs 164A and 164B pass through associated apertures in the housing 40. The contactor members 28 and 29 are respectively provided on the cable runs 164A and 164B and respectively co-operate with leaf spring type contacts 54A and 57A in the manner previously discussed.

In order to obtain the required degree of traction on the cable a pair of idler wheels 169 and 170 is provided. The idlers are so arranged relative to the pulley 166 that they co-operate with diametrically opposite sides of the pulley. The idlers are resiliently loaded towards the pulley 166. In the Figures the arrangements for preloading the idlers has been shown as a spring or clamp like element 171.

It will be appreciated that by using two preloaded idler wheels which are diametrically opposite to each other the resultant thrust exerted upon the motor output shaft 50 is balanced.

Also the individual amount of loading required for each individual idler is reduced.

One of the idler wheels 170 is used in conjunction with a contactor arm 55A as the means for producing the pulses that are applied to the second diode pump circuit 63 of the control unit. The control unit operates in a manner similar to that previously described.

A clutch 172 is interposed in the drive from the motor output shaft 50 and the pulley 166. The clutch is intended to respond to any overloading of the forces developed in the cable due to the door being obstructed in its movements. The clutch can be of any convenient type such as a resiliently loaded dog clutch.

Figure 18 schematically illustrates an alternative layout for the cable runs 1 64A and 164B. As can be seen a double sheaved pulley 173 is provided for introducing a change of direction in the cable run. This allows the motor and associated components to be mounted where-ever found convenient.

This pulley is mounted from a resiliently loaded support bracket whereby the pulley 173 forms part of the tensioning unit 169.

Figure 1 8A is a view of the structure of the pulley 173.

The clutch 172 is also shown in the Figure.

The cable path around the pulley 166 and the idlers 169, 170 can be varied with a view to improving traction with the cable.

Thus for example, the cable runs 164A and 164B can be arranged to engage the pulleys 169, 170 at locations diametrically opposite the locations shown in Figure 16. Figure 19 illustrates an arrangement in which the cable is able to wrap around substantially the whole of the circumference of the pulley 166.

Referring now to Figures 20 and 21 these illustrate an embodiment of the apparatus of the invention which employs a tensioned, fixed cable, chain, wire or like means 175.

One end of the cable 175 is secured to the door frame lintel by a cable clamp 176 and the other end of the cable 175 is connected to the rear wall of the garage by an anchorage 177 incorporating a cable tensioning device. The tensioning device is set so that the cable is taut.

A motor unit 178 is provided with a face plate 179 which mounts a main drive pulley 166 and two idler pulleys 169 and 170. These three pulleys engage the cable in the manner shown in Figure 22 so that rotation of the main pulley 166 causes the motor unit 178 to travel lengthwise of the cable.

An electronic control unit 180 is attached to the garage wall 181 and is connected to the unit 178 by conductor leads 182.

An optical detection unit 25 including a photocell is provided at a convenient location of the door frame 7 and is connected to the control unit 180 by conductors 183.

The cable is connected by way of a pivotal connector 184 to one end of a bracket 185 whose other end is pivotally connected to the top of a door of the Up-and-Over type.

It will be seen that the tensioned cable provides a track for the motor unit 178.

Thus as the motor unit travels lengthwise of the cable the door is caused to move in the direction set by the direction of movement of the coupling 184.

The contactor members 28 and 29 are provided adjacent the ends of the cable, the elements serving to activate switches (not shown) which are associated with the control unit 180.

The various control functions mentioned in connection with the opening and closing of a door are generally the same as those involved in the apparatus discussed hereinbefore.

If desired, the drive from the motor 23 to the main pulley can include the clutch 172 so that in the event of an obstruction the driving connection between the motor and the pulley 166 will be interrupted if the resistance to motion by the drive unit 182 exceeds a presettable level.

In the Figures it will be noted that the motor 23 drives the pulley 166 by way of a belt or chain drive. If desired a geared drive could be used.

Figure 23 illustrates the general construction of a tensioning device. This device includes a U bracket 188 attached to a support surface 189, an eyelet 190 to which the cable is to be attached, the eyelet having a threaded shank which engages a bore in the base of the bracket and is retained in the bracket 188 by a nut arrangement 192 which is resiliently loaded by a spring 193.

Figure 24 is a cross-sectional view of a clutch unit which is intended to be used with a drive wheel nut assembly. The drive wheel 47 is a rotatable fit on the nut and makes driving engagement with the nut by way of a load sensitive dog tooth clutch 194. The clutch includes a clutch ring 195 splined onto the body 196 of the nut. The ring 195 is axially slidable with respect to the nut body and thus the drive wheel 47.

The clutch ring 195 is resiliently loaded by a compression spring 197 held in place by a locking ring 198 engaged with a threaded portion at the end of the nut body. To vary the clutch release pressure the locking ring is rotated relative to the nut body.

The teeth of the clutch unit can be of any convenient form i.e., two diametrically opposed Vee section or semicircular section teeth. These constructions are shown.

A further embodiment of a movable cable operated system may be provided in which the cable 164 instead of being endless is wound upon a cable drum or windlass which is driven via a gear drive from the motor 23.

One end of the cable is attached to the drum. The cable is wrapped around the drum for a few turns and is then fed from the underside of the drum to engage with a pulley and thence from the pulley to engage with the upper side of the drum. The cable is then wrapped around the drum for a number of turns sufficient to provide adequate supply of cable for operational purposes and the other end of the table is secured to the drum end remote from the motor.

The door is attached to the lower run of the cable by a bracket.

With the above arrangement rotation of the drum in one direction winds cable from the lower run onto the drum and thds pulls the bracket towards the drum are in so doing opens the door. At the same time the cable winds off the other end of the drum.

Rotation of the cable in the reverse direction winds cable back onto the other end of the drum thereby pulling the bracket in the reverse direction so as to close the door. At the same time cable winds off the end of the drum adjacent to the motor.

It should be noted that at no time during the rotation of the drum does the cable wind upon itself whilst upon the drum but forms a single layer of cable on the drum. If desired a spiral cable groove can be provided upon the drum.

Tension in the cable is maintained by a cable tensioning unit. This unit can be a spring.

The cable is provided with the previously mentioned contactor members 28 and 29 these members cooperating with the contacts 54A and 57A in a manner to that discussed in relation to Figure 16.

WHAT WE CLAIM IS:- 1. Apparatus for displacing a door, window, lid or like closure member with respect to an opening that the door, window, lid or like closure member is required to be able to close or otherwise cover, the apparatus including an electric motor, a drive connection between the door, window, lid or the like closure member and the motor in which an element connectable to be moveable with the door, window, lid or like closure member, is caused to travel along a rectilinear path relative to the mounting structure for the door, window, lid or like closure member; control means for controlling the operation of the motor, the control means including means responsive to a motor operation signal of a predetermined characteristic for producing a control signal to which the motor responds; and further control means so responsive to resistance to the closing movements of the door, window, lid or like closure member during any point of its travel between its fully open position and its fully closed position as to cause reversal of the drive ,f the motor whereby subsequent operation of the motor is in the sense necessary to return the door, window, lid or the like closure member to its open position before the motor drive can be caused to effect a closing movement of the door, window lid or like closure member, the response of the further control means being such as to respond to a predetermined level of resistance to movement of the door, window, lid or like closure member to reverse move ment of the door, window, lid or like closure member, and also in the event of a jamming of the door, window, lid or like closure member against movement in the closing or opening direction to immobilise the motor.

2. Apparatus as claimed in claim 1, wherein the first mentioned control means is arranged to be responsive to an externally generated signal which is produced by means not physi

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **.

the driving connection between the motor and the pulley 166 will be interrupted if the resistance to motion by the drive unit

182 exceeds a presettable level.

In the Figures it will be noted that the motor 23 drives the pulley 166 by way of a belt or chain drive. If desired a geared drive could be used.

Figure 23 illustrates the general construction of a tensioning device. This device includes a U bracket 188 attached to a support surface 189, an eyelet 190 to which the cable is to be attached, the eyelet having a threaded shank which engages a bore in the base of the bracket and is retained in the bracket 188 by a nut arrangement 192 which is resiliently loaded by a spring 193.

Figure 24 is a cross-sectional view of a clutch unit which is intended to be used with a drive wheel nut assembly. The drive wheel 47 is a rotatable fit on the nut and makes driving engagement with the nut by way of a load sensitive dog tooth clutch 194. The clutch includes a clutch ring 195 splined onto the body 196 of the nut. The ring 195 is axially slidable with respect to the nut body and thus the drive wheel 47.

The clutch ring 195 is resiliently loaded by a compression spring 197 held in place by a locking ring 198 engaged with a threaded portion at the end of the nut body. To vary the clutch release pressure the locking ring is rotated relative to the nut body.

The teeth of the clutch unit can be of any convenient form i.e., two diametrically opposed Vee section or semicircular section teeth. These constructions are shown.

A further embodiment of a movable cable operated system may be provided in which the cable 164 instead of being endless is wound upon a cable drum or windlass which is driven via a gear drive from the motor 23.

One end of the cable is attached to the drum. The cable is wrapped around the drum for a few turns and is then fed from the underside of the drum to engage with a pulley and thence from the pulley to engage with the upper side of the drum. The cable is then wrapped around the drum for a number of turns sufficient to provide adequate supply of cable for operational purposes and the other end of the table is secured to the drum end remote from the motor.

The door is attached to the lower run of the cable by a bracket.

With the above arrangement rotation of the drum in one direction winds cable from the lower run onto the drum and thds pulls the bracket towards the drum are in so doing opens the door. At the same time the cable winds off the other end of the drum.

Rotation of the cable in the reverse direction winds cable back onto the other end of the drum thereby pulling the bracket in the reverse direction so as to close the door. At the same time cable winds off the end of the drum adjacent to the motor.

It should be noted that at no time during the rotation of the drum does the cable wind upon itself whilst upon the drum but forms a single layer of cable on the drum. If desired a spiral cable groove can be provided upon the drum.

Tension in the cable is maintained by a cable tensioning unit. This unit can be a spring.

The cable is provided with the previously mentioned contactor members 28 and 29 these members cooperating with the contacts 54A and 57A in a manner to that discussed in relation to Figure 16.

WHAT WE CLAIM IS:- 1. Apparatus for displacing a door, window, lid or like closure member with respect to an opening that the door, window, lid or like closure member is required to be able to close or otherwise cover, the apparatus including an electric motor, a drive connection between the door, window, lid or the like closure member and the motor in which an element connectable to be moveable with the door, window, lid or like closure member, is caused to travel along a rectilinear path relative to the mounting structure for the door, window, lid or like closure member; control means for controlling the operation of the motor, the control means including means responsive to a motor operation signal of a predetermined characteristic for producing a control signal to which the motor responds; and further control means so responsive to resistance to the closing movements of the door, window, lid or like closure member during any point of its travel between its fully open position and its fully closed position as to cause reversal of the drive ,f the motor whereby subsequent operation of the motor is in the sense necessary to return the door, window, lid or the like closure member to its open position before the motor drive can be caused to effect a closing movement of the door, window lid or like closure member, the response of the further control means being such as to respond to a predetermined level of resistance to movement of the door, window, lid or like closure member to reverse move ment of the door, window, lid or like closure member, and also in the event of a jamming of the door, window, lid or like closure member against movement in the closing or opening direction to immobilise the motor.
2. Apparatus as claimed in claim 1, wherein the first mentioned control means is arranged to be responsive to an externally generated signal which is produced by means not physi

cally connected with the control means and which externally generated signal is of a predetermined characteristic.
3. Apparatus as claimed in claim 1 or 2, wherein the motor operation signal is comprised of an electromagnetic waveform such as an optical, radio waves or the like.
4. Apparatus as claimed in claim 1 or 2, wherein the first mentioned control means includes arrangements adapted to respond to the motor operation signal provided that the arrangements receive the signal for at least a predetermined period of time.
5. Apparatus as claimed in any preceding claim, wherein the first mentioned control means is adapted to produce from the control signal a further signal which maintains the motor in operation after the initiating signal has ceased, and wherein said further signal is conditional upon the door, window, lid or like closure member being displaced at a predetermined speed.
6. Apparatus as claimed in claim 5, wherein said further signal is arranged to maintain energising current in a first relay circuit serving to control energisation of the motor.
7. Apparatus as claimed in any one of claims 1 to 6, wherein the control means is arranged to arrest or inhibit further displacement of the door, window, lid or like closure member after the latter has been displaced by a predetermined amount from an initial position.
8. Apparatus as claimed in claim 7, wherein the control means is arranged to exert a braking effect upon the movements of the door, window, lid or like closure member after the latter has been displaced by a presettable distance or amount.
9. Apparatus as claimed in claim 8, wherein the control means includes means for reversing the direction of the motor in advance of stopping of operation of the motor, the arrangement being such as to produce said braking effect.
10. Apparatus as claimed in any one of the preceding claims, wherein the control means includes means for sensing when the door, window, lid or like closure member has been displaced in a first direction by a predetermined amount and for inhibiting or preventing further movement of the door, window, lid or like closure member in this first direction.
11. Apparatus as claimed in claim 10, and in which the control means, following inhibiting or arresting of the movement of the door, window, lid or like closure member in the first direction is arranged to condition the displacement means for effecting displacement of the door, window, lid or like closure member in a second or opposite direction upon receipt of a further operation initiating signal.
12. Apparatus as claimed in claim 10 as appendent to claim 6, wherein the control means includes means for reversing the direction of rotation of the motor, the reversing means being arranged for control by a second relay circuit, and wherein the control means includes switch means responsive to the position of the door, window, lid or like closure member for controlling the energisation conditions of the second relay circuit.
13. Apparatus as claimed in claim 12, wherein said second relay circuit is connected to receive said further signal, and wherein the position responsive switch means is arranged to control the effect that the further signal has upon the operational state of the second relay circuit.
14. Apparatus as claimed in claim 13, wherein the response time of the second relay circuit is less than that of the first relay circuit, the arrangement being such that when the second relay circuit has been caused to change its operational state following operation of the position responsive switch means the reversing switch means is operated prior to cessation of operation of the motor.
15. Apparatus as claimed in any one of claims 10 to 14, wherein the means for sensing is arranged to sense when the door, window, lid or like closure member has been displaced in the second or opposite direction by a predetermined amount and to inhibit or arrest further movement in said opposite direction.
16. Apparatus as claimed in claim 15, wherein the control means includes a second switch means responsive to the position of the door, window, lid or like closure member for controlling the energisation conditions of the second relay circuit.
17. Apparatus as claimed in claim 15 or 16, wherein the control means, following said inhibiting or arresting of the movement of the door, window, lid or like closure member in the second or the opposite direction is arranged to cause the reversal of the motor direction of rotation so that upon receipt of a further operation initiation signal the displacement means is arranged to displace the door, window, lid or like closure member in said first direction.
18. Apparatus as claimed in any one of the preceding claims 1 to 17, wherein the control means is arranged to integrate the operation initiating signal over a predetermined time period, the arrangement being such that if the result of the integration attains a predetermined reference level the drive to the door, window, lid or like closure member can be initiated.
19. Apparatus as claimed in claim 18, wherein a diode pump circuit is arranged to effect said integration of the operation initiating signal.
20. Apparatus as claimed in claim 18 as appendent to claim 6, wherein an electronic switch circuit is included in the energisation circuit of the first relay circuit, and wherein the output of the diode pump circuit is arranged to control the switching state of the electronic switch circuit in such manner that the latter is 'opened' when the pump circuit produces an output of a predetermined level.
21. Apparatus as claimed in any one of claims 6 to 20, wherein the means for producing the further signal includes means for producing electrical pulses, the frequency of the pulses being related to the speed at which the door, window, lid or like closure member is being displaced.
22. Apparatus as claimed in claim 21, wherein a second diode pump circuit is connected to receive said pulses, the arrangement being such that provided said pulses attain a predetermined frequency the diode pump circuit is able to produce a control output.
23. Apparatus as claimed in claim 21, wherein the second diode pump circuit output is arranged to control the operational state of a second electronic switch circuit.
24. Apparatus as claimed in claim 22 as appendent to claim 6, wherein the second electronic switch is included in the energisation circuit of the first relay cricuit, the arrangement being such that when the second electronic switch receives said control output from the second diode pump circuit said first relay circuit is maintained in the state in which its keeps the motor energised.
25. Apparatus as claimed in claim 23 as appendent to claim 11, wherein the second electronic switch is arranged to control operadon of the energisation circuit of the second relay circuit.
26. Apparatus as claimed in any one of claims 1 to 25, wherein the control means is a swtich unit which is arranged to reverse the direction of displacement when said resistance to displacement occurs whilst the door, window, lid or like closure member is being displaced in a particular direction whereby the door, window, lid or like closure member is returned to its original position.
27. Apparatus as claimed in any one of the preceding claims, wherein the motor operation initiating signal is an optical signal, and wherein the control means includes means responsive to an optical signal.
28. Apparatus as claimed in claim 27, wherein the means responsive to the optical signal includes an optical signal detection means, and means for integrating the output of the detecting means over a predetermined time period, the arrangement being such as to produce a control signal when the output crosses a predetermined level.
29. Apparatus as claimed in claim 27, and including a first light responsive means so positioned with respect to the structure as to be responsive to light directed along a predetermined path, and means so responsive to output from the light responsive device as to produce a control signal when the integrated intensity of the light received by the device is at least equal to a predetermined value.
30. Apparatus as claimed in claim 29, wherein the means responsive to the output from the light responsive device is arranged to produce an output on receipt of a single flash of light lasting for a predetermined time period and of a predetermined intensity level.
31. Apparatus as claimed in claim 29, wherein the means responsive to the output from the light responsive device is arranged to produce an output whenever a plurality of light flashes are received within a predetermined time interval and the cumulative light quanta exceeds said predetermined value.
32. Apparatus as claimed in claim 29, wherein the means responsive to the output from the light responsive device is arranged to integrate the outputs derived from a succession of light flashes presented to the device within a predetermined time interval and to produce an output if the integrated signal level exceeds a predetermined value.
33. Apparatus as claimed in any one of claims 29 to 32, wherein said first light responsive device is related to movement in a first direction, and wherein a second light responsive device is provided for receiving light signals associated with initiation of displacement in the opposite direction.
34. Apparatus as claimed in claim 33, wherein said means responsive to the first light responsive device is also responsive to output from the second light responsive device.
35. Apparatus as claimed in any one of the preceding claims, wherein the means for displacing the door, window, lid or like closure member includes a guide track, means for mounting the guide track in a predetermined direction with regard to said structure and to the direction along which said door, window, lid or like closure member is to be moved, means for producing relative motion between the motor and the track, and means for coupling the door, window, lid or like closure member with the motor/track combination such that the door, window, lid or like closure member is displaced by said relative motion.
36. Apparatus as claimed in claim 35, wherein said track comprises a bar, rod, shaft or like element adapted for pivotal connection to the door, window, lid or like closure member, and wherein means are provided for supporting the element for axial movement with respect to the structure whereby on producing said relative motion the element is axially displaced thereby moving the door, window, lid or like closure member.
37. Apparatus as claimed in claim 36, wherein the element is screw threaded and drive is transmitted to the element by a nut engaged with the element and coupled for rotation by the drive from the motor.
38. Apparatus as claimed in claim 37, wherein a load sensitive clutch arrangement is provided in the drive from the motor to the nut.
39. Apparatus as claimed in claim 35, wherein said track comprises a bar, rod, shaft or like element which is constrained against axial and rotational movement with respect to said structure, and wherein the drive arrangement includes drive means adapted for axial traversal of the element on production of said relative motion, said drive means being coupled to the door, window, lid or like closure member.
40. Apparatus as claimed in claim 39, wherein the element is screw threaded and drive is transmitted to the element by way of a nut engaged with the element and coupled for rotation by the drive transmission from the motor.
41. Apparatus as claimed in claim 40, wherein a load sensitive clutch arrangement is provided in the drive from the motor to the nut.
42. Apparatus as claimed in any one ot claims 1 to 34, wherein the means for displacing the door, window, lid or like closure member includes a screw threaded bar, rod, shaft or like element adapted fpr pivotal connection to the door, window, lid or like closure member, means for supporting the element such that the element is axially displaceable with respect to the structure, a nut rotatable with respect to the element but constrained against axial displacement of the element, and means for transmitting drive from the motor to the nut, the arrangement being such that rotation of the nut displaces the element.
43. Apparatus as claimed in claim 42, wherein a friction drive, a gear drive, or a belt or chain drive is provided for transmitting drive from the motor.
44. Apparatus as claimed in claim 42 or 43, wherein the nut is rotatably carried in a support unit forming a first part of said support means for the element.
45. Apparatus as claimed in claim 44, wherein the first part of the support means is pivotally connected to a second part of the support means for pivotal movement about an axis transverse to the movement direction of the element.
46. Apparatus as claimed in any one of claims 42 to 45, wherein a load sensitive clutch arrangement is provided in the drive between the motor and the element.
47. Apparatus as claimed in claim 38, 41 or 46, wherein a wheel, roller or the like which is connected to receive drive from the motor is coaxially and rotatably carried by the nut, and wherein drive from the wheel, roller or the like to the nut is by way of the load sensitive clutch.
48. Apparatus as claimed in claim 35, wherein the guide track comprises a cable, chain, wire or like element which is positionally fixed with respect to said structure, and wherein the drive transmission includes drive means adapted for axial traversal of the element on production of said relative motion, said drive means being coupled with the door, window, lid or like closure member.
49. Apparatus as claimed in claim 35, wherein the guide track comprises a movable cable, chain wire or like element which is movable with respect to said structure, and wherein said door, window, lid or like closure member to be displaced is coupled to the element, the arrangement being such that the drive transmission is arranged to displace the element relative to the structure.
50. Apparatus as claimed in claim 47, 48 or 49, wherein the drive transmission includes a drive pulley and idler pulley combination for producing relative traction conditions with the element.
51. Apparatus as claimed in claim 50, wherein a load sensitive clutch is arranged in the drive from the motor to the drive pulley.
52. Apparatus as claimed in any one of claims 35 to 51, wherein electrical contactor members are provided at predetermined locations of the track, the arrangement being such that at predetermined positions of said relative motion electrical control signals are produced which are utilised to initiate control means for inhibiting or arresting the relative motion.
53. Apparatus as claimed in claim 27 and any one of claims 28 to 52 as appended thereto, and wherein the means responsive to the optical signal is a photocell, and wherein a light emitting diode arrangement is provided for enabling optimum adjustment of the photocell.
54. Apparatus as claimed in claim 53, and including manually operable switch means for enabling operation of the control means and thus the displacement of the article in the absence of an externally generated operation initiating signal.
55. Apparatus as claimed in any one of the preceding claims and including means for protecting the motor against overheating.
56. Apparatus as claimed in claim 55, wherein said means includes a thermistor circuit arrangement.
57. Apparatus as claimed in any one of the preceding claims and including a locking mechanism for mechanically or electric mechanically retaining the article in a predetermined position.
58. Apparatus as claimed in claim 57, wherein the locking mechanism is arranged to automatically operated and controlled by the displacement producing arrangements for the door, window, lid or like closure member.
59. Apparatus for displacing a door, window, lid or like closure member constructed and arranged to operate, substantially as hereinbefore described with reference to Figures

1 to 10, Figure 11, 12 or 13, Figures 1 to

10 with the feature of Figures 14A to 14D, Figures 15 to 17, Figures 18 and 19, Figures 20 to 23, or any of these Figures with the feature of Figure 24.
60. A garage door opening and closing apparatus when comprising apparatus as claimed in any one of the preceding claims.
61. A garage door assembly when including apparatus as claimed in any one of the preceding claims.