GATE SYSTEMS

Abstract: A gate system comprising two parallel barriers (2), (4) defining an entryway into a zone. A gate (6) is pivotal about an upright axis at one side of the zone and is movable between a closed position at which it extends across the zone and open position at which it extends in the direction of the zone adjacent one barrier (2). The gate (6) is driven from a motor (20) via a flexible coupling (22), a gear box (24) and a coupling device (26) and a spring loaded clutch (28). When the gate (6) is at its closed position the gate is locked in that position by locking the coupling device (26). The gate can, however, be moved to its open position notwithstanding this locking by application of force to the gate whereby to exert sufficient pressure to release the spring loaded clutch (28). Approach of persons towards the gate system, in an intended allowed direction of passage therethrough, at the entrance (10) thereto, is detected by use of a photocell (12) which causes the gate to be moved to its open position for a predetermined period and then reverted to its closed position. Approach of persons to the exit side (16) is detected by a detector arrangement (14) effective to generate an alarm, when such approach is detected.

Description: GATS SYSTEMS The present invention relates to gate systems for controlling entry or exit of persons into or from a zone, for example a supermarket. According to the present invention, there is provided a system for controlling entry or exit of persons to or from a zone, comprising a power-operated barrier pivotal between a closed and open position, means for locking the barrier in its closed position, and meaHS for locking the barrier in its open position until a person has passed the barrier. An embodiment of the invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a schematic plan view of a gate system in accordance with a preferred embodiment of the inven¬ tion; Figure 2 is an end view of the gate system; Figures 3 and 4 are sections showing a gate operating mechanism; Figures 5 and 6 are, perspectively, a section and a plan of a locking arm of the operating mechanism; Figures 7 and 8 are views of two alternative forms of detector useful in the invention; and Figure 9 is an end view of a modified gate system. As shown in Figures 1 and 2, a gate system com¬ prises two parallel barriers 2, 4, preferably formed by rails, defining an entryway into a zone, for example a shopping zone of a supermarket, the barriers 2, 4 being spaced by a distance sufficient to permit passage of a conventional shopping trolley. Movement through the entryway is subject to the control of a gate 6 which automatically opens and closes. The operating mechanism for the gate is housed in a vertical column 8 mounted adjacent one of the barriers, the operating mechanism being actuated to open the gate 6 in response to detec¬ tion of the presence of a person or shopping trolley at the entrance 10 to the entryway by means of a 12 or other detector arrangement at the entrance. A similar detector arrangement 14 is associated with the exit side 16 in order to detect the presence of a person attempting to enter the entryway from the exit side, and to actuate an alarm. The gate operating mechanism which is housed within the column 8 is shown in Figures 3 to 6.and comprises an electric motor 20 mounted with its axis vertical and connected via a flexible coupling 22 to the input of a gear box 24. The output of the gear box 24 is connected to the driving side of a coupling device 26; the driving side being linked by a lost-motion connection to the driven side of the coupling device. The coupling device 26, which will be described in detail hereinafter, is associated with a locking device which locks the gate in its open and closed positions to prevent the gate from being pushed manually. The driven side of the coupling device 26 is connected to the driving side of a spring- loaded clutch 28, the driven side of the clutch 28 being connected to a vertical drive shaft 30 which forms an integral part of the gate 6. The clutch 28, which will also be described in detail hereinafter, releases on application of a relatively high force to the gate 6 in order to permit the gate 6 to be opened manually in the event of an emergency. The vertical drive shaft 30 carries control cams 32 which operate switches 34 to control the operation of the driving motor 20 and the alarm. The coupling device 26 comprises driving and driven plates 40, 42 respectively. The driving plate 40 includes a driving pin 44 received within an arcuate slot 46 in the driven plate 42 whereby the driving plate 40 is able to move through a limited angular extent relative to the driven plate 42 whereafter the driving pin 44 entrains the driven plate 42 for movement with the driving plate. The peripheral edge of the driving plate 40 is shaped to define a cam 48 which controls the operation of two locking arms 50, one arm serving to lock the driven plate 42, and thus the gate 6, in the closed position, and the other of which serves to lock the driven plate, and thus the gate, in the open posi- tion, only one of the two arms 50 being shown in the drawings, although both arms are identical. Each arm 50 is pivotally mounted on a respective bracket 52 attached to the column 8, the end of the arm being movable substantially radially towards and away from the peri- pheral edge of the driven plate 42. The end of the arm co-operates with a locking lug 54 projecting from the periphery of the driven plate 42 so as to act as an abutment for the locking lug when the gate is in its open or closed position whereby to prevent manual movement of the gate from its open to its closed posi- tion or vice versa unless the gate is pushed with sufficient force to disengage the clutch 28. Each arm 50 carries a follower roller 56 which engages the cam 48 defined on the peripheral edge of the driving plate 40. A compression spring 58 interposed between the arm 50 and the bracket 52 biases the arm radially inwardly in order to maintain the follower roller 56 in contact with the cam 48. Rotation of the driving plate 40 and thus of the cam 48 effects, via the follower roller 56, radially outwards movement of the arm in order to disengage the arm 50 from the locking lug 54. The operation of the gate operating mechanism will now be described. As explained above, in the closed position of the gate, the appropriate locking arm 50 engages one of the two locking lugs 54 on the periphery of the driven plate 42, thereby locking the gate 6 against manual opening. Upon detection of a person or shopping trolley by the photocell 12 at the entry side of the entryway, the driving motor 20 is actuated in the opening direction. The initial movement of the driving plate 40 consequent upon actuation of the motor 20 results. in movement of the driving pin 44 along the slot 46 in the driven plate 42. During this initial movement of the driving plate 40, its cam 48 effects via the follower roller 56, pivotal movement of the locking arm 50 in order to release the end of the arm 50 from engagement with the lug 54, whereby to permit rotation of the driven plate, and thus of the gate, when the pin 44 reaches the end of the slot 46 and entrains the driven plate for rotation with the driving plate. When the gate reaches its open position, the control cams 32 on the driving shaft 30 actuate the switches 34 so as to start a timer and to de-activate the alarm in order to inhibit operation of the alarm during passage past the photocell 14 at the exit side 16 of the entryway. In the open position, the second locking arm 50 engages the second of the two locking lugs 54 on the driven plate 42, to lock the driven plate 42, and thus the gate 6 against rotation in the reverse direction. The open position of the gate 6 is defined by engagement of a stop lug 60 carried by a driving plate 62 of the clutch 28 with a fixed stop 64 carried by the column 8 of the mechanism. When the gate is in its open position, the driving motor 20 remains actuated in the opening direc¬ tion in order to maintain the stop lug 60 firmly against the fixed stop 64 to thereby prevent oscillation of the gate. After a predetermined, and preferably adjustable, time sufficient to allow a person to pass through the entryway, the timer effects reversal of the current to the motor 20 in order to drive the motor 20 in the closing direction. The initial movement of the motor results in movement of the driving plate 40 relative to the driven plate 42 until the driving pin 44 reaches the opposite end of the arcuate slot 46 and entrains the driven plate for movement. During this initial move- ment, the cam 48 of the driving plate 40 effects, via the follower roller 56 of the second locking arm 50, release of the second locking arm from the locking lug 54 thereby permitting the subsequent rotation of the driving plate and of the gate. Also, when the motor 20 is switched into its reverse mode, the alarm is automat- ically reset so that the alarm will operate if the gate 6 is held open by a person standing at the exit side 16 of the entryway. Upon reaching the closed position, the stop lug 60 on the clutch driving plate 62 engages a second fixed stop 66 carried by the column 8, and the switches 34 are operated by the cams 32 on the driving shaft 30 in order to de-energise the motor. As the gate moves into its closed position, the first locking arm 50 latches behind the stop lug 54 on the driven plate 42 in order to prevent subsequent manual opening of the gate. The clutch 28 comprises driving and driven plates 62, 68 drivingly interconnected by means of a radial roller 70 engaged in radial grooves in the adjacent surfaces of the two plates, the driving plate 62 being biased into engagement with the driven plate 68 by means of a compression spring 12. By pushing the gate hard in the event of emergency, the groove in the clutch driven plate 68 disengages from the roller 70 and in so doing pushes the clutch driving plate 62 downwardly against the bias of the compression spring 72. The gate can then be moved manually into its open position. Resetting of the clutch is effected by returning the gate to its closed position whereon the roller 70 will, under the bias of the compression spring 72, snap back into engagement within the groove in the clutch driven plate 68. Although the invention has been described in relation to entry gates for supermarkets, the invention is applicable to other applications where a gate is used to provide access to an area to which controlled entry and exit is required. In the modified gate system shown in Figure 9 the motor 20 is again arranged with its output shaft vertical for driving the gear box 24. In this instance however the output shaft from the gear box 24, extending vertically therefrom, is attached directly to a plate 124 which is rotated directly under action of the motor 20 to move the barrier 6. The locking of the gate 6 at its open and closed positions is effected by means of a magnetically actuated clutching device 126 which is effective, when actuated, to move a plate 128, coaxially arranged with the output shaft from the gear box 24, into engagement with the underside of the plate 124 to frictionally lock that plate in position. In this instance, the previously described coupling device 26 is not required since, due to the frictional nature of the interlocking between the plate 124 and plate 128 when the gate is locked, it is possible to nevertheless move the barrier 6 against resistance provided by that frictional coupling (and by the inertia of the motor 20 through the gear box 24) so that the plates 124, 128 rotationally slide one over the other. In the arrangement of Figure 9, the control of the gate is effected under influence of suitable detectors as aforedescribed and by use of micro switches establishing the open and closed positions of the gate. While in the described arrangements, detector means is used to detect passage of a person coming towards the gate in the wrong direction, for sounding and alarm, it is also possible to arrange that such alarm is, alternatively or additionally, actuated under the condition of actual movement of the gate 6 from its closed position to an open position. In the latter of regard, it will be appreciated that the gate 6 may simply be arranged to pivot through 180°, such as to have a central closed position at which it extends transversely across the zone through which passage is to be controlled and to two different open positions at which the barrier is respectively rotated 90° in one direction from the closed position, to lie against one side of the zone, and 90° in the other direction from the closed position to lie, relatively oppositely directed, again along the side of the zone. In this case, normally, the gate would be arranged to be opened in one direction away from its closed position to one of the open positions, such as by rotation in a clock-wise direction as viewed in plan. In such instance, the direction of opening is arranged to have a component of movement in the intended allowed direction of passage through the zone, since this is easiest for persons so wishing to traverse through the zone. On the other hand, persons intending to pass through the zone in a reverse direction, being the direction in which passage is to be discouraged, will more naturally tend to move the gate in the direction opposite to the normal opening direction, such as anti-clock-wise in the just mentioned example given, to position the gate at its other open position. In this instance. then, the alarm may be arranged to be actuated upon detection of movement of the gate to the last mentioned open position. This may simply be effected by use of a cam operated micro switch, suitably positioned. The detection of a person approaching the entryway at the entrance 10 or at the exit side 16 may be effected as described by use of photocells such as the photocell 12. Other devices such as passive infra-red devices, may be used. More particularly, however, Figure 7 shows a form of detector device 70 which has been found particularly satisfactory. Device 70 comprises a generator 80 of low power microwave radiation of signal frequency f Q , two detectors 82, 84 for receipt of reflected microwave radiation such as from the person 86 shown approaching the device 70, a comparator 88 and an actuating device 90 such as a relay. The generator 80 may be constructed in usual fashion for microwave radiation devices. One such device is, for example, described in my Inter- national Patent Application No. PCT/AU84/00089. The generated radiation is directed outwardly from the location at which detection is to be effected, such as away from the entryway at the entrance 10 or the exit side 16 thereof. The receivers 82, 84 are each generally constructed in conventional fashion such as described in the aforementioned International Patent Application No. PCT/AU84/00089 and are responsive to generate electrical signals responsive to incidence of reflected radiation thereon. However, the receivers 82, 84 are, by mechanical design or by insertion of elec¬ trical filters, designed to be responsive principally to frequencies displaced from the frequency f- by prede¬ termined amounts, f Q - f , and f Q + f respectively where f is a pre-selected frequency displacement. The outputs from the receivers 82, 84 will thus differ in accordance with whether a person 86 is as shown approaching the device 70 or moving away therefrom. More particularly, due to the so-called doppler effect, in the instance where the person is approaching the detector the frequency of reflected radiation will be increased by an amount proportional to the velocity of approach and, in the event the person is moving away from the device 70 the frequency will be decreased by an amount proportional to the velocity of recession. For this reason, the receiver 82, which is responsive to a lower frequency f Q - f , will in the case where the person is approaching the detector 84 provide a relatively low output compared with the detector for increased frequency, since the sensitivity of that lower frequency responsive receiver 82 will be less, with respect to the reflected signal, than will be the sensitivity of the receiver 84 responsive to higher fre¬ quency signal. Conversely, when the person 86 is moving away from the device 70, the receiver 82 responsive to lower frequency signals will, for the same reasons, provide a greater output than that of the receiver 84 responsive to higher frequency signals. The comparator 88 is effective to compare the outputs from the two receivers 82, 84 and provide an output only in the event that a desired one of the two signals from receivers 82, 84 is greatest, for actuating device 90 for, for example, operating the motor 20 only in the instance that a person 86 is approaching the entry way at the entrance 10 or for, for example, operating an alarm and/or locking the entryway on approach of a person to the entryway at the exit side 16. In the latter case it is particularly important that the detector be not responsive to persons traversing through the entryway in the normal direction and the ability of the device 70 to discriminate such movement from movement towards the entryway is thus of great importance. Figure 8 shows an alternative arrangement in which the generator 80 is of the same form as described in relation to Figure 7. Here, only a single receiver 87, generally like the receiver 82 or 84 is employed, but being non-frequency selective so as to simply provide at its output an electrical signal, the magnitude and frequency of which correspond to the magnitude and frequency of the incoming reflected signal at the receiver 87. Here, two filters 94, 96 are provided, connected to.the output of receiver 87 and tuned to the respective frequencies f→ - f and f fl + f to provide that the output from one filter will be greater than the other in accordance with whether or not the person is approaching or moving away from the device 70. A comparator 88 like the comparator 88 in Figure 7 is employed to compare the outputs of the filters 94, 96 and operate the device 90 in the same way as previously described. In the embodiment of Figure 7 then the two receivers themselves comprise detectors for signals of different frequencies. In the embodiment of Figure 8, two such detectors are formed by the receiver 87 and the filters 94, 96. The arrangement of Figure 7 can however be further modified to enable it to function even where the receivers 82, 84 are not frequency selective, by positioning the receivers to be displaced along the line of propagation of the reflected signal. By suitably selecting the spacing between the receivers, bearing in mind the wavelength of the reflected signal, the receivers will generate oscillatory electrical signals of frequency equal to the frequency of the reflected signal but of phase displacement proportionate to the spacing of the receivers. As an object moves in the vicinity of the detector, the phase relationship between the receiver outputs will vary and this variation can be detected to detect the direction of movement. It will be seen, from the above, that the invention provides in this aspect an improved detector device comprising means for generating an oscillatory signal transmittable through air, detector means responsive to reflected said signal from an object, for detecting presence of said object, the detector means including means responsive to the frequency of the reflected signal for determining whether the object is moving towards or away from the detector. In one form, the invention contemplates that the detector means comprises two detectors responsive to frequencies respectively above and below the frequency of the oscillatory signal as generated and means for comparing the outputs of such receivers. The detectors may comprise receivers which each receive reflected said oscillatory signal and generate outputs which are representative of the pre¬ sence of signals above and below the said frequency respectively or may comprise filters coupled to a single receiver which receives the reflected oscillatory signal. Although the ' described detector device uses low power microwave energy, other oscillatory signals transmittable through air may be used, such as ultra- sonic sound signals. The invention has been described as preferably including means for warning of any attempt by a person to pass through the entryway in the wrong direction. That is to say, as mentioned, by using photocells or the described detectors such as shown in figures 7 and 8, an alarm is raised if a person approaches the entryway at the exit " side 16. The alarm which is operated may comprise for example flashing lights or a buzzer or electrically operated bell. However in one particular form of the invention, the alarm mechanism which is so operated includes means for generating an audio signal reproducing a human voice conveying a message to the effect that the person approaching the entryway at the exit side is so proceeding to pass in the wrong direction and, for example, requesting that the person not so pass through the entryway. The releyant voice signal may be generated by operating a pre-recorded tape in a tape play back machine or, more preferably from a programmable artificial device such as suitably programmed read only memory device. In instances where approach of persons towards the entryway is detected similar arrangements may be made for generating a voice signal providing suitable information to such approaching persons. For example a welcoming message may be provided or information may be given as to particular services or goods being offered for sale at a store with which the entryway is associated.

Claims: CLAIMS : 1. A system for controlling entry or exit of persons to or from a zone, comprising a power-operated barrier pivotal between a closed and open position, means for locking the barrier in its closed position, and means for locking the barrier in its open position until a person has passed the barrier. 2. A system for controlling entry or exit of persons to or from a zone, as claimed in claim 1, comprising rotatable means carrying said barrier and drive means for rotating said rotatable means to effect movement of the barrier between said closed and open positions and wherein said locking means comprises first engagement means rotatable in accordance with rotation of said rotatable means and second engagement means effective to engage the first engagement means to effect said locking. 3. A system for controlling entry or exit of persons to or from a zone, as claimed in the claim 2, wherein said first engagement means comprises a peripherally outwardly extending projection mounted for rotational movement with said rotatable means, said second engagement means comprising a movable member movable towards and away from the rotatable means and engaging the projection when positioned at an inward location. 4. A system for controlling entry or exit of persons to or from a zone, as claimed in claim 2 or claim 3, including cam means for moving said second engagement means out of engagement with said first engagement means, prior to movement of the rotatable means to effect opening movement of the barrier. 5. A system for controlling entry or exit of persons to or from- a zone, as claimed in claim 4, wherein said rotatable means is arranged for driving from an axially aligned drive member the drive member being coupled to the rotatable means by a lost motion linkage whereby, on initial rotation of the drive member in a direction for turning the rotatable means in a direction for moving the barrier from its closed position, the rotation of the drive member is not initially transferred to the rotatable means to effect turning thereof until such time as the first and second engagable members are disengaged. 6. A system for controlling entry or exit of persons to or from a zone, as claimed in any preceding claim, wherein said locking of said barrier in said closed position is such as to permit the barrier to be moved to its open position under application of manual force thereto. 7. A system for controlling entry or exit of persons to or from a zone, as claimed in claim 6, wherein a pressure releasable coupling is incorporated in drive means for said barrier to permit said barrier to be 17 moved to its open position by application of said manual force. 8. A system for controlling entry or exit of persons to or from a zone, as claimed in claim 7, wherein said coupling comprises an electro magnetic coupling. 9. A system for controlling entry or exit of persons to or from a zone, as claimed in any preceding claim, including means for sensing approach of a person to said zone from one direction being a direction opposite to an intended direction of passage of persons through the zone and effective to generate a warning signal on such approach said means not being effective to so generate a warning on approach of persons to the zone in the intended direction of passage therethrough. 10. A system for controlling entry or exit of persons to or from a zone, as claimed in any preceding claim wherein said barrier is swingable about a pivotal mounting from a position at which it extends at one side of said zone substantially there across, at which the barrier is in its closed position, to a position at which it extends from its pivotal mounting parallel to the direction of extent of the zone and at one side thereof, wherein the barrier is at its open position, by rotation of the barrier through an angle of approximately 90°, the swinging motion of the barrier in moving from the closed to the open position having a directional component directed in a normally intended direction of allowed passage through the zone, the barrier also being oppositely rotatable through a further angle of approximately 90° from the closed position to a further open position, under influence of said pressure applied thereagainst. 11. A system for controlling entry or exit of persons to or from a zone, as claimed in claim 10 including means for detecting movement of said barrier to said further open position for generating an alarm under such condition. 12. A system for controlling entry or exit of persons to or from a zone as claimed in any preceding claim having a detector effective on approach of a person to the zone in an intended direction for passage therethrough, to move said barrier from its closed to its open position, and after a time delay, to revert the barrier again to its closed position. 13. A system for controlling entry or exit of persons to or from a zone as claimed in any preceding claim, including a reverse approach detector for detection of approach to said zone of persons so approaching in a direction not corresponding to an intended direction for passage through said zone and effective to generate an alarm on detection of such approach. 14. A system for controlling entry or exit of persons to or from a zone, as claimed in claim 12 wherein said detector means comprises means for generating an oscillatory signal transmittable through air, detector means responsive to reflected said signal from an object, for detecting presence of said object, the detector means including means responsive to the frequency of the reflected signal for determining whether the object is moving towards or away from the detector. ABSTRACT gate system comprising two parallel barriers (2), defining an entryway into a zone. A gate (6) is pivotal about an upright axis at one side of the zone and is movable between a closed positions at which it extends across the zone e€ an open position at which it extends in the direction of the zone adjacent one barrier (2) . The gate (6) is driven from a motor (20) via a flexible coupling (22) , a gear box (24) and a coupling device (26) and a spring, loaded clutch (28). When the gate (6) is at its closed position the gate is locked in that position by locking the coupling device (26) . The gate can, however, be moved to its open position not withstanding this locking by application of force to the gate whereby to extert sufficient pressure to release the spring loaded clutch (28) . Approach of persons towards the gate system, in an intended allowed direction of passage therethrough, at the entrance (10) thereto,is detected by use of a photocell (12) which causes the gate to be moved to its open position for a predetermined period and then reverted to its closed position. Approach of persons to the exit side (16) is detected by a detector arrangement (14) effective to generate an alarm, when such approach is detected.

Inventors: CARROLL NOEL, CARROLL, NOEL
Applicants: CARROLL NOEL, CARROLL, NOEL
Application year: 1985
Main classification: E05F15
IPC codes: E05F15, E06B11