US3678623A

US3678623A - Control system for revolving door

Info

Publication number: US3678623A
Application number: US50281A
Authority: US
Inventors: Keith T Jenkins
Original assignee: C J RUSH Ltd
Current assignee: C J RUSH Ltd; Metex Corp USA
Priority date: 1970-06-26
Filing date: 1970-06-26
Publication date: 1972-07-25
Anticipated expiration: 1989-07-25

Abstract

An electronic control system for a revolving door, in which four cams, one for each door leaf, rotate with the door and open a single fixed position switch each time the door is in a quarterclose position. When the door is pushed from the quarter-close position, the switch closes, energizing a circuit which controls a motor to rotate the door for a timed interval. During the timed interval the circuit renders ineffective the periodic opening and closing of the position switch as the door rotates. After the timed interval, the first time the door passes a quarter-close position, the actuation of the position switch causes the circuit to switch the motor to drive the door at low speed and the next switch actuation, 90 degrees later, stops the door in a quarterclose position.

Description

United States Patent Jenkins [54] CONTROL SYSTEM FOR REVOLVING 211 Appl. No.: 50,281

[52] U.S. Cl. ..49/43, 60/52 CD, 318/466 [51] Int. Cl ..E05d 15/02 [58] Field of Search ..49/43, 42, 46, 29, 30, 32, 49/264; 60/52 CD; 318/467, 466, 272; 188/180,

[56] References Cited UNITED STATES PATENTS 3,497,997 3/1970 Sheckells ..49/43 51 July 25,1972

3,526,820 9/1970 Sheckells ..49/43 X Primary ExaminerJ. Karl Bell Attorney-Rogers, Bereskin & Parr [57] ABSTRACT An electronic control system for a revolving door, in which four cams, one for each door leaf, rotate with the door and open a single fixed position switch each time the door is in a quarter-close position. When the door is pushed from the quarter-close position, the switch closes, energizing a circuit which controls a motor to rotate the door for a timed interval. During the timed interval the circuit renders ineffective the periodic opening and closing of the position switch as the door rotates. After the timed interval, the first time the door passes a quarter-close position, the actuation of the position switch causes the circuit to switch the motor to drive the door at low speed and the next switch actuation, 90 degrees later, stops the door in a quarter-close position.

10 Claims, 7 Drawing Figures Patented July 25, 1972 3 Sheets-Sheet 1 8 'IIIIIIA 44 FIG. 4

HYDRAULIC INVEN'I'OR. KEITH T. JENKINS MOTOR l 1, 2O 2 A 24 T 38 36 HYDRAQ/L/C PUMP 24 MOTOR srop 51.0w L SOLENOID SOLENOID T I VALVE VALVE l 32 96 1 ELECTRIC T MOTOR 4O CONTROL CIRCUIT 42 POSITION SWITCH [116 5 y Patented July 25, 1972 3 Sheets-Sheet 2 I'VVENTOR KEITH T. JENKINS CONTROL SYSTEM FOR REVOLVING DOOR This invention relates to a control system for a revolving door. More particularly, the invention relates to a control system which, in response to an initial movement of the door by a user, rotates the door for a timed period and then brings the door to rest in a given position.

Revolving doors of the type having four door leaves projecting radially at 90 intervals from a central rotary shaft are well known. Most such doors are manually operated, i.e. they are moved by the user pushing on a horizontal push bar, with the door speed commonly being limited by a damping device. A major disadvantage of the manually operated revolving door was that after use, it came to rest in a random position in which usually only a single door leaf separated the inside of the building from the outdoors. This was undesirable, since it resulted in a relatively high heat loss from the building and allowed drafts to enter the building. Although such doors could be brought to rest in a quarter-close position (in which there are two door leaves separating the indoors from the outdoors on either side of the central rotary shaft), users passing through the doors did not normally concern themselves with the position in which the doors come to rest.

More recently, revolving doors have been used which are power operated. These doors have a motor which revolves the door when the user pushes the door. However, the control systems for such power operated revolving doors have been unsatisfactory in that they required a number of switches to control the door, and they often failed to bring the door accurately to rest in the desired position.

Accordingly, it is an object of the present invention to provide a novel control system for a revolving door, which system includes a single position switch to sense the door position and which brings the door to rest accurately in a desired position following a timed interval.

To this end the invention provides a control system for a revolving door comprising:

a. drive means for driving said door,

b. a position switch, and means for switching said position switch between a first condition when said door is in a predetermined position and a second condition when said door is in a position other than said predetermined position,

c. and control means coupled between said drive means and said position switch for controlling operation of said drive means, said control means including 1. means responsive to switching of said position switch from its first to its second condition to initiate operation of said drive means and to maintain said drive means operated at a predetermined speed for at least a predetermined period of time independent of the condition of said position switch,

2. means responsive to switching of said position switch following termination of said predetermined time to terminate operation of said drive means at said predetermined speed, such switching of said position switch being a stop-initiate switching,

3. and means for bringing said door to a standstill at a selected position within a predetermined angular rotation of said door following said stop-initiate switching of said position switch.

Further objects and advantages of the invention will appear from the following description, taken together with the accompanying drawings, in which:

FIG. I is a top plan view, in section, showing a typical revolving door in a quarter-close position;

FIG. 2 is a side sectional view of the bottom portion of the revolving door of FIG. l,showing a position switch according to the invention and earns for operating the position switch;

FIG. 3 is a view taken along lines 13-15 of FIG. 2;

FIG. 4 is a sectional view taken along lines 4-4 of FIG. 3;

FIG. 5 is a schematic diagram showing the arrangement of a control circuit, electric motor, pump and hydraulic motor for operating the door; and

FIGS. 6A and B shows in detail an electronic circuit for the control circuit of FIG. 5.

Reference is first made to FIGS. 1 and 2 which show a conventional revolving door 2 having a central shaft 4 and door leaves 6 projecting radially from the shaft. The door leaves are four in number, as is conventional, and are spaced apart by the usual The door is shown in FIG. 1 as being in a quarterclose position, in which an air lock is created between each half of the door frame 5 and two of the door leaves. (As is conventional for four leaf doors, the door frame 5 includes a pair of opposed curved halves 5a each extending through an angle of slightly more than 90.)

The shaft 4 of the door is supported at its bottom by a flat plate 8 which rests on bearings 10. The bearings 10 are in turn supported on another plate 12 which is supported in a housing 14 buried in the floor 16. A wiper diagrammatically indicated at 18 seals the space between the plate 8 and the floor 16.

The door 2 is rotated by a hydraulic motor 20 mounted on the bottom of the plate 12. A square cross-section driveshaft 22 projects upwardly from the hydraulic motor into a square cross-section opening 23 (FIG. 3) in the bottom of the shaft 4. The hydraulic motor 20 is powered by hydraulic fluid in

conduits

24, 26 which pass through a duct 28 to a pump 30 (FIG. 5). The pump 30 is driven by an AC-DC electric motor 32 (FIG. 5), the speed of which is controlled by a control circuit 34.

Positioned in the conduit 24 (which is the return conduit from the hydraulic motor to the pump) is a slow" solenoid valve 36 and a fast" solenoid valve 38. When not energized, both permit unrestricted flow of fluid through the conduit 24. when the slow solenoid valve 36 is energized, it prevents flow of fluid therethrough, but some fluid flow past valve 36 is permitted by a restricted bypass 40. However, when stop solenoid valve 28 is energized, it virtually completely prevents flow of fluid through conduit 24.

Information as to the position of the door is supplied to the control circuit by a position switch 42 (FIGS. 1 and 2). The position switch 42, which is typically a conventional micro switch, is mounted on the stationary plate 12 and is actuated by four cams 44 mounted on the lower surface of the revolving plate 8. Each cam 44 is positioned beneath a corresponding door leaf 6 and is several inches wide. The switch 42 is positioned as shown in FIG. 1, so that it is depressed by one of the earns 44 whenever the door is in a quarter-close position. (The position of the cams and switch can of course be changed while still maintaining their relationship such that the switch 42 is depressed whenever the door is in a quarter-close position.)

The operation of the apparatus so far described is generally as follows. When a user pushes the door from the quarterclose position shown in FIG. 1, the position switch 42 (which is open when depressed in the quarter-close position) opens. This signals the control circuit 34, which in a manner to be described, then energizes the electric motor 32 and at the same time releases(de-energizes)the slow solenoid valve 36 and the stop solenoid valve 38. The electric motor 32 then drives the pump 30 which powers the hydraulic motor 20, and the door rotates at a fixed speed for a timed period set by the control circuit. During the timed period circuits in the control circuit 34 render inefiective the periodic opening and closing of the position switch 42 as the cams 44 rotate therepast.

At the end of the timed period, the control circuit again becomes responsive to the opening and closing of the position switch 42, and at the next opening of the position switch (i.e. when the door passes the next quarter-close position following the end of the timed interval), the control circuit responds by energizing the slow solenoid valve 36 and at the same time reducing the speed of the electric motor 32. The door is now braked to a much slower speed and rotates at this speed for a predetermined angular displacement (normally either 90 or at which time the control circuit energizes the stop solenoid to bring the door to a stop at a quarter-close position.

Reference is next made to FIGS. 6A and B which show in detail a preferred electronic circuit for the control circuit 34. in FIGS. 6A and B, detached contact notation is used for the relays, Le. a dash indicates a relay contact which is closed when the relay is released (not energized), and an X indicates a relay contact which is open when the relay is released. In addition, typical values for the components are shown in parenthesis in FIGS. 6A and B. (Resistances are Kohms; capacitances are microfarads.)

The control circuit includes

terminals

50, 52 which are connected to the conventional 110 volt AC supply.

Terminals

50, 52 are connected to the electric motor 32 through a silicon controlled rectifier SCR (or other suitable thyristor), the firing angle of which controls the energy supplied to the motor 32 and hence the speed of the motor. The gate of the SCR is connected both to a slow speed control circuit 54 and to a high speed control circuit 56. The slow speed control circuit 54 consists of resistor R1 and variable resistor R2 connected in series with a diode across the supply voltage, with a capacitor Cl connected across resistor R2. The potential at the tap of resistor R2 is coupled through a contact SL-l of a slow relay SL and through a contact FA-l of a fast relay FA to the gate of the SCR. When relay SL is energized and relay FA is released, circuit 54 will control the firing angle of the SCR in conventional manner, dependent upon the setting of variable resistor R2 and hence upon the time required for capacitor C1 to charge to the triggering potential of the SCR.

Similarly, fast speed control circuit 56 consists of a resistor R3 and a variable resistor R4 connected in series with a diode across the supply voltage, with a capacitor C2 connected across resistor R4. The potential at the tap of resistor R4 is coupled through a contact FA-2 of fast relay FA to the gate of the SCR. Thus, when the fast relay FA is energized, the fast speed control circuit 56 will control the motor speed, while when the fast relay is released and the slow relay is energized, the slow relay SL will control the motor speed. When both the fast and slow relays are released, the motor 32 will not operate.

The coil of the slow solenoid valve 36 is connected across the

terminals

50, 52 through a contact FA-3 of the fast relay, and the coil of the stop solenoid valve 38 is connected across terminals. 50, 52 through a contact SL-2 of the slow relay and the contact FA-3 of the fast relay.

The

terminals

50, 52 also supply power through a step down transformer 60 to a full wave bridge generally indicated at 62. The full wave bridge energizes

terminals

64, 66 with a DC supply voltage, typically +12 volts and ground respectively.

The slow relay SI. is connected in series with the contact indicated at 8-1, of the position switch 42, the series combination being connected across the

terminals

64, 66. The junction between relay SL and contact 8-1 is connected through a diode and through a resistance shown to the base of transistor Q1. The collector of transistor 01 is connected as shown to the base of transistor 02, to control transistor 02, and the collector of transistor O2 is connected in turn to the base of a transistor 03 to control transistor Q3. The collector of transistor O3 is connected to the fast relay FA, so that when transistor O3 is on, relay FA operates. The collector of transistor Q3 is connected to controltransistors Q4 and Q5,and is also connected via lead 67 so that when transistor Q3 changes state, it initiates operation of a timing circuit containing unijunction transistor 06. Base 1 (the lower base) of the unijunction transistor O6 is connected to the base of transistor 07, to change the state of transistor Q7 when the timing circuit completes its timing functions, and the collector of transistor 07 is connected to the base of transistor Q8 to control this transistor. The collector of transistor 08 is connected to the base of transistor Q10; the collector of transistor Q10 is connected to the base of transistor Q11, and the collector of transistor Q11 is in turn connected to the base of transistor Q12. This arrangement controls the operation of the electric motor 32 when the door is initially pushed, until the timed interval is completed and the position switch opens again, at which time the circuit up to transistor Q12 reduces the motor speed and energizes the slow solenoid valve, as will be described.

A further circuit 48, consisting of transistors 013 to Q16 inclusive, is provided in the event that it is desired after initiation of the stopping procedure to have the door rotate at slow speed past the first quarter-close position encountered to the next quarter-close position (i.e. The circuit 48 consisting of transistors Q13 to Q16 provides a timed function which disables the effect of the position switch as the door rotates past the first quarter-close position following the initiation of the stopping procedure, as will be described.

The details of the circuit will be best understood from a description of its operation, which is as follows. Initially, with the door stationary in a quarter-close position and position switch 42 depressed, the circuit components have the initial conditions shown in Table 1 below.

TABLE 1 Component Condition Motor 32 off Slow solenoid valve 36 energized Stop solenoid valve 38 energized Position switch contact S-l open Slow relay SL not energized Transistor Q1 nonconducting Transistor Q2 conducting Transistor Q3 nonconducting Fast relay FA not energized Transistor Q4 nonconducting Transistor Q5 conducting Transistor Q6 nonconducting (i.e.

base 1 low) Transistor Q7 nonconducting Transistor Q8 conducting Transistor Q10 conducting Transistor Q11 nonconducting Transistor Q12 conducting Transistor Q13 nonconductin g Transistor Q14 conducting Transistor Q15 nonconducting i.e.

base 1 low) Transistor Q16 nonconducting When a user pushes the door from the quarter-close position, contact 5-1 of the position switch closes, energizing the slow relay SL. This opens contact SL-Z, releasing the stop solenoid valve 38 and permitting slow movement of the door. At the same time, contact SL-l closes, connecting the slow speed control circuit 54 to the gate of the SCR so that the motor 32 commences running at slow speed.

In addition, when position switch contact 8-! closes, a low voltage pulse is applied via lead 70 to the base of transistor Q1, turning transistor Q1 on. This produces a positive voltage at the collector of transistor Q1, turning transistor Q2 off, and the resultant decreased voltage at the collector of transistor Q2 turns transistor Q3 on, energizing fast relay FA.

When relay FA operates, its contact FA-l opens to disconnect the slow speed control circuit 54 from the gate of the SCR, and its contact FA-2 closes to connect the fast speed control circuit 56 to the gate of the SCR to drive the motor 32 at high speed. At the same time, contact FA-3 opens to release the slow solenoid valve 36, thereby removing substantially all restriction from the hydraulic fluid conduit 24 so that the pump can drive the hydraulic motor at high speed. The door thus commences rotating at a relatively high speed determined by the setting of variable resistor R4 (typically 8 to 12 RPM).

When transistor 02 turns off, the low voltage at its collector is applied through leads 72 and 74 to the base of transistor 01 to hold transistor Q1 on during intervals when theposition switch contact 8-! opens, as the door rotates past the quarterclose positions. As the door rotates and contact S-l opens periodically, slow relay SL releases and reoperates. However, this has no efiect since at this time the fast relay FA is operated, and only the contacts of relay FA have any effect.

When transistor Q3 turns on to energize the fast relay PA, the positive voltage at its collector turns transistor Q4 on, thus turning transistor Q5 off and turning off a lamp 76 in the emitter circuit of transistor Q5, for a purpose to be described.

In addition, when transistor Q3 turns on, initiating fast operation of the door, the positive voltage at its collector energizes unijunction transistor Q6 and also energizes the timing circuit consisting of resistors R6, R7 and capacitor C3 connected to the emitter of unijunction transistor Q6. Capacitor C3 now charges with a time constant dependent on the values of the components. After a predetermined interval of time (which is typically adjustable between and 30 seconds, dependent on the setting of variable resistor R6), the unijunction transistor Q6 is triggered and a positive pulse is produced at its base 1. This positive pulse is applied to the base of transistor Q7 to turn on transistor Q7, and the resultant low voltage pulse at the collector of transistor Q7 turns off transistor Q8.

Transistor Q10 is normally held on by the low voltage ap plied from the collector of transistor Q8 through lead 78 and resistor R10 to the base of transistor Q10. However, when transistor Q8 becomes nonconducting (due to operation of unijunction transistor Q6), a positive voltage is applied through lead 78 to the base of transistor Q10, tending to turn off transistor Q10. (A further positive voltage is applied to the base of transistor Q10 from base 1 of unijunction transistor Q6 through resistors R11, R12 and R10.) However, transistor Q10 is held on at this time, assuming that the door is between quarter-close positions, because a low voltage is applied to its base from the closed position switch contact S-l through leads 80,81 and resistor R15.

As soon as the door passes the next quarter-close position following completion of the timing function, position switch contact S-l opens and removes the low voltage which, applied through

leads

80,81 held transistor Q10 on. The positive voltage from the collector of transistor Q8 and from base 1 of transistor Q6 then turns transistor Q10 011. This initiates the stopping procedure. The resultant voltage at the collector of transistor Q10 turns transistor Q11 on, thereby turning transistor Q12 off.

When transistor Q12 turns off, the resultant low voltage at its collector, applied through lead 82 to the base of transistor 02, reoperates transistor Q2. When transistor Q2 reoperates, the resultant positive voltage at its collector turns transistor Q3 off, thereby releasing fast relay FA.

When relay FA releases, its contact FA-l closes and its FA-2 opens connecting slow speed control circuit 54 to the gate of the SCR in place of fast speed control circuit 56. The door is now driven at a slower speed governed by the setting of variable resistor R2 (typically 2 to 5 RPM). At the same time, contact FA-3 closes to energize the slow solenoid valve 36, thus rapidly braking door from fast to slow speed.

The rate at which the motor 32 is slowed is controlled (apart from normal deceleration) by transistors Q4 and Q5. When transistor Q3 turns off to release fast relay FA, this removes the positive potential from the base of transistor Q4. Transistor 04 then turns off (and hence transistor Q5 turns on) at a rate governed by the discharge of capacitor C5 connected to the base of transistor Q4. Transistor Q5 thus gradually turns on, increasing the brightness of lamp 76 connected in its emitter circuit. Lamp 76 is positioned to shine on a light dependent resistor LDR, the resistance of which decreases with increasing light. Resistor LDR is connected between the gate and the cathode of the SCR, and as its resistance decreases, the energy delivered to the motor 32 is decreased, thereby giving a controlled deceleration of the motor until the final slow speed setting is reached. It may be noted that normally transistors 04, Q5 and resistor LDR are not needed, since the mechanical inertia of the parts is sufficient to give a controlled although relatively rapid deceleration.

ignoring for the present time the effect of transistors Q13 to 016, the door now rotates at slow speed until it reaches the next quarter-close position, at which time the position switch contact S-l again opens. When contact S-1 opens, this releases slow relay SL, thereby opening contact SL-l and shutting off the motor 32. At the same time, contact SL-2 closes to energize the stop solenoid valve 42, thereby bringing the door to a stop. The cams 44 are made sufi'iciently wide with reference to the slow speed of the door that when the slow solenoid valve 36 is energized as the door approaches the leading edge of a cam 44, the door will come to a stop before the trailing edge of the cam 44 moves off the position switch 42.

The circuit is now ready for re-use, and a new cycle will commence as soon as a user pushes the door again. Transistor Q8 is restored to its initial conductive condition when transistor Q2 reoperates to release fast relay FA, by reason of the positive pulse applied from the transistor Q2 collector through conductor 84 to the base of transistor 08. When transistor Q8 turns on, it in turn restores transistor Q7 to its initial nonconducting condition by reason of the low voltage pulse occuring at its collector and transmitted through lead 78 and resistor R12 to the base of transistor Q7. With the operation of the circuit as described, the door is brought to a stop after the fast relay is released. In other words, the door rotates one quarter revolution at slow speed and then stops. This is commonly termed a 90 stop.

The foregoing description of the operation is slightly simplified in that it has ignored the effects of transistors Q13 to Q16 in timing circuit 48. Timing circuit 48 is provided when it is desired to have a choice between the 90 stop discussed, and a stop (in which the door rotates 180 after the initiation of the stopping procedure).

The timing circuit 48 includes a 180 stop switch S2, which is closed for 90 stops and which is opened for 180 stops. The timing circuit 48 functions as follows.

When transistor Q11 turns on (which occurs at the initiation of the stop procedure), the positive voltage at its collector, applied through capacitor C7, diode D7, and resistor R16, turns on transistor Q13. Whentransistor Q13 turns on, the low voltage at its collector is applied through lead 86 back to the base of transistor Q1 to hold transistor Q1 on even when contact S-1 opens, and at the same time this low voltage is applied to the base of transistor Q14 to turn transistor Q14 off. When transistor Q14 turns off, the resultant positive voltage at its collector, applied through

leads

88, 90 to the base of transistor Q13, holds transistor Q13 on (the pulse applied through capacitor C7 to turn transistor Q13 on was of short duration).

In addition, when transistor Q14 turns off, the positive voltage at its collector, applied through resistor R17, turns transistor Q16 on. When transistor Q16 turns on, the resultant low voltage at its collector, applied through lead 80, holds slow relay SL operated.

When transistor Q14 turns off, the positive voltage at its collector also increases the charging voltage to capacitor C10 in the emitter circuit of unijunction transistor Q15. After a time interval determined by the component values transistor Q15 fires, and the resultant positive pulse generated at its base 1, applied via lead 94, resets transistor Q14 to its on condition, thereby turning transistors Q13 and Q16 off again.

With the 180 stop switch S2 closed, as shown, the timing interval of transistor Q15 is very short, and transistors Q13, Q16 turn on and off before the door rotates 90 from the initiation of the stopping procedure. They thus have no efl'ect, and with switch S2 closed, the door stops 90 after initiation of the stopping procedure.

However, with switch S2 open, the initial charge on capacitor C10 is reduced, and capacitor C10 takes longer to charge to a level sufficient to fire transistor Q15. In fact, transistor Q15 does not fire until after the door has rotated more than 90 (but less than 180) following initiation of the stopping procedure. Therefore, with switch S2 open, when position switch contact S-l opens at the quarter-close position following initiation of the stopping procedure, this opening has no effect. Relay SL is held on by the low voltage supplied through transistor Q16 and lead 80, and transistor Q1 is held on by the low voltage applied from the collector of transistor Q13 through lead 86. The door therefore continues to rotate towards the next quarter-close position. Before it reaches that next quarter-close position, transistor Q15 fires as discussed, turning off transistors Q13, Q16 and hence transistor 01. Then, when the door reaches the next quarter-close position (180 past the initiation of the stopping function), and position switch contact S-l opens, slow relay SL releases as before, energizing the stop solenoid valve to stop the door, and also shutting off the motor 32. if the door is pushed so that it moves past the normal stopping position, then a new cycle will be initiated.

Normally there is enough leakage through the stop solenoid valve so that a user can push the door out of a quarter-close position even though the stop solenoid valve is energized. However, if desired, a pressure switch can be provided connected in the return conduit 24 from the hydraulic motor to the pump as indicated at 96 in FIG. 5. When a user pushes the door, causing the hydraulic motor to pump fluid into the pump and raising the pressure in conduit 24 beyond a predetermined level (normally greater than that occuring during normal operation of the pump), 8 normally closed contact S-3 (FIG. 6A) of the pressure switch opens, applying a low voltage pulse through capacitor C11 to the base of transistor Q1 and thus turning transistor Q1 on. This initiates a cycle of operation of the door. The pressure switch mechanism is of course optional.

If desired, and provided that 90 stops for the door are desired, the slow speed drive for the motor can be entirely eliminated, provided that the high speed drive is sufficiently fast that the door will consistently coast at least 90 from the time when the high speed drive is removed. In this case, depending on the friction in the door, some braking of the door may be desired (as provided by the slow speed solenoid valve), to ensure that the door will be moving slowly enough so that it can be stopped by energizing the stop solenoid valve 90 after removal of the highspeed drive. However, such a system is subject to variations in the friction in the door and to some extent on operation by users, and therefore the system described is much preferred, in which the door is rapidly braked to slow speed and is then driven at slow speed until the time when the stop solenoid is energized.

In addition, although the earns 44 have been shown as spaced 90 apart, they could if desired be spaced at greater intervals, e.g. 180. In that case, any two opposed cams of the four cams shown in FIG. 3 will be used. All stops will then be at least 180 degree stops, and the timing circuit 48 which provides a choice between 90 stops and 180 stops can be eliminated (unless a choice between 180 stops and 360 stops is desired, in which case circuit 48 will be retained with appropriate changes in component values). Alternatively only one cam could be used, in which case all stops would be 360 stops. However, four cams are preferred for greater flexibility (assuming that the door has four leaves).

Although it has been assumed that the door has four leaves, it will be appreciated that it could have a greater or lesser number, as desired, with appropriate changes in the cams and component values.

if desired, the control circuit can include a continuous run switch 84 (FIG. 6A) connected between fast relay FA and the positive supply. Whenever switch 8-4 is closed, relay FA will be energized and the door will rotate continuously.

What I claim as my invention is:

l. A control system for a revolving door of the kind having four leaves and four quarter-close positions, comprising:

a. drive means for driving said door,

b. a single position switch, and means for switching said position switch between a first condition when said door is in a predetermined position and a second condition when said door is in a position other than said predetermined position, said predetermined position being at least two of said quarter-close positions, such two quarterclose positions being 180 apart,

2. means responsive to switching of said position switch following termination of said predetermined time to terminate operation of said drive means at said predetermined speed, such switching of said position switch being a stop-initiate" switching,

3. and means for bringing said door to a standstill at a selected position within a predetermined angular rotation of said door following said stop-initiate switching of said position switch, said selected position being one of said two quarter-close positions,

. said control means further including means responsive to said stop-initiate switching of said position switch for braking said door following said stop-initiate switching of said position switch, to reduce the speed of said door to a second predetermined speed slower than said first predetermined speed, and means responsive to said stopinitiate switching of said position switch for operating said drive means at said second predetermined speed during movement of said door through said predetermined an gular rotation,

e. said drive means including an electric motor, a hydraulic pump driven by said motor, a hydraulic motor, conduit means connecting said pump and said hydraulic motor and said means for braking said door comprising: slow solenoid valve means connected in said conduit means, said slow solenoid valve means having a first condition in which it permits substantially unrestricted flow of fluid through said conduit means and a second condition in which it restricts flow of fluid through said conduit means, means for placing said slow solenoid valve means in its first condition during said predetennined time interval, and means connected between said slow solenoid valve means and said means (c) (2) for switching said slow solenoid valve means to its second condition upon said stop-initiate switching of said position switch, thus rapidly to brake said door to said second predetermined speed.

2. Apparatus according to claim 1 wherein said means (c) (3) includes stop solenoid valve means in said conduit means in series with said slow solenoid valve means and having a first condition in which it permits substantially unrestricted flow of fluid to said conduit means and a second condition in which it substantially prevents flow of fluid through said conduit means, means for placing said stop solenoid valve means in its first condition during said predetermined time interval and during movement of said door through said predetermined angular rotation, and means responsive to a predetermined switching of said position switch from its second to its first condition following said stop-initiate switching of said position switch to switch said stop solenoid valve means to its second condition to stop said door.

3. Apparatus according to claim 1 wherein said predetermined position is each of said four quarter-close positions, so that said position switch is in its first position whenever said door is in a quarter-close position and is in its second condition between quarter-close positions, said selected position being a quarter-close position.

4. A control system for a revolving door of the kind having four leaves and four quarter-close positions, comprising:

a. drive means for driving said door,

2. means responsive to switching of said position switch following termination of said predetermined time to terminate operation of said drive means at said predetennined speed, such switching of said position switch being a stop-initiate switching,

d. said control means further including means responsive to said stop-initiate switching of said position switch for braking said door following said stop-initiate switching of said position switch, to reduce the speed of said door to a second predetermined speed slower than said first predetermined speed, and means responsive to said stopinitiate switching of said position switch for operating said drive means at said second predetermined speed during movement of said door through said predetermined angular rotation,

f. said position switch being mounted in a fixed position, and said means for switching said position switch comprises at least two actuators mounted to rotate with said door, said actuators being spaced 180 apart, and said actuators and said position switch being located such that said position switch is actuated by a said actuator during each of said two quarter-close positions of said door.

5. Apparatus according to claim 4 wherein each said actuator is a cam.

6. Apparatus according to claim 5 wherein said predetermined position is each of said four quarter-close positions of said door, said cams being four in number and being spaced 90 apart, said position switch being in contact with a said cam during each of the four quarter-close positions of said door, said predetermined angular rotation being through substantially 90.

7. Apparatus according to claim 6 wherein said predetermined position is each of said four quarter-close positions of said door, said cams being four in number and being spaced 90 apart, said position switch being in contact with a said cam during each of the four quarter-close positions of said door, said predetermined angular rotation being through substantially 180, said means (c) (3) including timer means for maintaining operated said means for operating said drive means at said second predetermined speed as said door rotates and as said position switch changes condition once from its second condition to its first condition following said stop-initiate switching of said position switch.

8. Apparatus according to claim 4 wherein said control means includes thyristor means having control terminal means, said means (c) (1) including fast speed control circuit connected to said control terminal means to control the firing angle of said thyristor means, and said means for operating said drive means at said second predetermined speed includes a separate slow speed control circuit connected to said control terrninal'means to provide a different firing angle for said thyristor means, said means (c) (2) including means for disconnecting said fast speed control circuit from said control terminal means and for connecting said slow speed control circuit to said control terminal means upon said stop-initiate switching of said position switch.

9. Apparatus according to claim 4 wherein said means (c) (1) includes first, second and third transistors each switchable between conducting and nonconducting states, means connecting said transistors for change of state of said first transistor to change the state of said second transistor and for change of state of said second transistor to change the state of said third transistor, means connecting said first transistor with said position switch for the state of said first transistor to change when said door moves away from said predetermined position, a timing circuit connected to said third transistor to commence timing said predetermined period upon change of state of said third transistor consequent upon moving of said door from said predetermined position and consequent change of state of said first and second transistors, means connected to said third transistor for initiating and maintaining operation of said drive means at said predetermined speed upon said last mentioned change of state of said third transistor, said means (c) (2) including a further transistor, means connecting said timing circuit to said further transistor for enabling said further transistor upon expiry of said predetennined period, means connecting said further transistor and said position switch for operating said further transistor upon switching of said position switch following expiry of said predetermined period, and means connecting said further transistor with said second transistor for switching the state of said second transistor upon switching of said further transistor thus to switch the state of said third transistor and to release said means for initiating and maintaining operation of said drive at said predetermined speed.

10. Apparatus according to claim 9 wherein said means for initiating and maintaining said operation of said drive means at said predetermined speed is a fast relay connected in the collector circuit of said third transistor, said apparatus further including a slow relay, and means connecting said slow relay for change of state upon switching of said position switch from its second to its first condition following said stop-initiate switching of said position switch, and means responsive to change of state of said slow relay means to terminate movement of said door.

Claims

1. A control system for a revolving door of the kind having four leaves and four quarter-close positions, comprising: a. drive means for driving said door, b. a single position switch, and means for switching said position switch between a first condition when said door is in a predetermined position and a second condition when said door is in a position other than said predetermined position, said predetermined position being at least two of said quarter-close positions, such two quarter-close positions being 180* apart, c. and control means coupled between said drive means and said position switch for controlling operation of said drive means, said control means including 1. means responsive to switching of said position switch from its first to its second condition to initiate operation of said drive means and to maintain said drive means operated at a predetermined speed for at least a predetermined period of time independent of the condition of said position switch, 2. means responsive to switching of said position switch following termination of said predetermined time to terminate operation of said drive means at said predetermined speed, such switching of said position switch being a ''''stopinitiate'''' switching, 3. and means for bringing said door to a standstill at a selected position within a predetermined angular rotation of said door following said stop-initiate switching of said position switch, said selected position being one of said two quarter-close positions, d. said control means further including means responsive to said stop-initiate switching of said position switch for braking said door following said stop-initiate switching of said position switch, to reduce the speed of said door to a second predetermined speed slower than said first predetermined speed, and means responsive to said stop-initiate switching of said position switch for operating said drive means at said second predetermined speed during movement of said door through said predetermined angular rotation, e. said drive means including an electric motor, a hydraulic pump driven by said motor, a hydraulic motor, conduit means connecting said pump and said hydraulic motor and said means for braking said door comprising: slow solenoid valve means connected in said conduit means, said slow solenoid valve means having a first condition in which it permits substantially unrestricted flow of fluid through said conduit means and a second condition in which it restricts flow of fluid through said conduit means, means for placing said slow solenoid valve means in its first condition during said predetermined time interval, and means connected between said slow solenoid valve means and said means (c) (2) for switching said slow solenoid valve means to its second condition upon said stop-initiate switching of said position switch, thus rapidly to brake said door to said second predetermined speed.

2. means responsive to switching of said position switch following termination of said predetermined time to terminate operation of said drive means at said predetermined speed, such switching of said position switch being a ''''stop-initiate'''' switching,

3. and means for bringing said door to a standstill at a selected position within a predetermined angular rotation of said door following said stop-initiate switching of said position switch, said selected position being one of said two quarter-close positions, d. said control means further including means responsive to said stop-initiate switching of said position switch for braking said door following said stop-initiate switching of said position switch, to reduce the speed of said door to a second predetermined speed slower than said first predetermined speed, and means responsive to said stop-initiate switching of said position switch for operating said drive means at said second predetermined speed during movement of said door through said predetermined angular rotation, e. said drive means including an electric motor, a hydraulic pump driven by said motor, a hydraulic motor, conduit means connecting said pump and said hydraulic motor and said means for braking said door comprising: slow solenoid valve means connected in said conduit means, said slow solenoid valve means having a first condition in which it permits substantially unrestricted flow of fluid through said conduit means and a second condition in which it restricts flow of fluid through said conduit means, means for placing said slow solenoid valve means in its first condition during said predetermined time interval, and means connected between said slow solenoid valve means and said means (c) (2) for switching said slow solenoid valve means to its second condition upon said stop-initiate switching of said position switch, thus rapidly to brake said door to said second predetermined speed.

3. and means for bringing said door to a standstill at a selected position within a predetermined angular rotation of said door following said stop-initiate switching of said position switch, said selected position being one of said two quarter-close positions, d. said control means further including means responsive to said stop-initiate switching of said position switch for braking said door following said stop-initiate switching of said position switch, to reduce the speed of said door to a second predetermined speed slower than said first predetermined speed, and means responsive to said stop-initiate switching of said position switch for operating said drive means at said second predetermined speed during movement of said door through said predetermined angular rotation, f. said position switch being mounted in a fixed position, and said means for switching said position switch comprises at least two actuators mounted to rotate with said door, said actuators being spaced 180* apart, and said actuators and said position switch being located such that said position switch is actuated by a said actuator during each of said two quarter-close positions of said door.

4. A control system for a revolving door of the kind having four leaves and four quarter-close positions, comprising: a. drive means for driving said door, b. a single position switch, and means for switching said position switch between a first condition when said door is in a predetermined position and a second condition when said door is in a position other than said predetermined position, said predetermined position being at least two of said quarter-close positions, such two quarter-close positions being 180* apart, c. and control means coupled between said drive means and said position switch for controlling operation of said drive means, said control means including

5. Apparatus according to claim 4 wherein each said actuator is a cam.

6. Apparatus according to claim 5 wherein said predetermined position is each of said four quarter-close positions of said door, said cams being four in number and being spaced 90* apart, said position switch being in contact with a said cam during each of the four quarter-close positions of said door, said predetermined angular rotation being through substantially 90*.

7. Apparatus according to claim 6 wherein said predetermined position is each of said four quarter-close positions of said door, said cams being four in number and being spaced 90* apart, said position switch being in contact with a said cam during each of the four quarter-close positions of said door, said pre-determined angular rotation being through substantially 180*, said means (c) (3) including timer means for maintaining operated said means for operating said drive means at said second predetermined speed as said door rotates and as said position switch changes condition once from its second condition to its first condition following said stop-initiate switching of said position switch.

8. Apparatus according to claim 4 wherein said control means includes thyristor means having control terminal means, said means (c) (1) including fast speed control circuit connected to said control terminal means to control the firing angle of said thyristor means, and said means for operating said drive means at said second predetermined speed includes a separate slow speed control circuit connected to said control terminal means to provide a different firing angle for said thyristor means, said means (c) (2) including means for disconnecting said fast speed control circuit from said control terminal means and for connecting said slow speed control circuit to said control terminal means upon said stop-initiate switching of said position switch.

9. Apparatus according to claim 4 wherein said means (c) (1) includes first, second and third transistors each switchable between conducting and nonconducting states, means connecting said transistors for change of state of said first transistor to change the state of said second transistor and for change of state of said second transistor to change the state of said third transistor, means connecting said first transistor with said position switch for the state of said first transistor to change when said door moves away from said predetermined position, a timing circuIt connected to said third transistor to commence timing said predetermined period upon change of state of said third transistor consequent upon moving of said door from said predetermined position and consequent change of state of said first and second transistors, means connected to said third transistor for initiating and maintaining operation of said drive means at said predetermined speed upon said last mentioned change of state of said third transistor, said means (c) (2) including a further transistor, means connecting said timing circuit to said further transistor for enabling said further transistor upon expiry of said predetermined period, means connecting said further transistor and said position switch for operating said further transistor upon switching of said position switch following expiry of said predetermined period, and means connecting said further transistor with said second transistor for switching the state of said second transistor upon switching of said further transistor thus to switch the state of said third transistor and to release said means for initiating and maintaining operation of said drive at said predetermined speed.