Abstract:
A door controlling device for opening and closing a door in a wall having a linkage connecting between the door and a wall and an arm pivotable about a pin. A drive member on the pin has a stand by position which does not interfere with the manual movement of the door. Rotation of the drive member in one direction rotates the arm around the pin to move the door to the open position and rotation of the drive member in the opposite direction rotates the arm around the pin to move the door to the closed position.

Description:
The present invention relates to a moter driven mechanism for opening and closing a door, in particular, to a mechanism wich can be operated remotely from the door. 
     BACKGROUND OF THE INVENTION 
     Several devices are available which use an electric motor to control the opening and closing of a door to a room. Devices are also available for which the opening or closing cycle can be initiated from a remote location using an infrared transmitter and the like such as disclosed in U.S. Pat. No. 5,040,331. Such door controlling devices must be constructed so that they do not suffer damage when the door is manually opened or closed. Similarly, they must be constructed so they do not to suffer damage when an object such as a chair blocks movement of the door during an opening or closing cycle. 
     Currently available door controlling devices utilize a slip clutch or the like which create a drag or resistance when the door is manually opened or closed. Such slip clutches do not terminate the door opening or closing cycle when the movement of the door is interrupted by contact with an item such as a chair or a person&#39;s hand and, as a result, such devices apply a force against the obstruction until the operating cycle is completed. It is, therefore, desirable to provide a door controlling device which can be operated remotely to open and close a door, which will not create resistance when the door is not manually opened or closed, and for which the opening or closing cycle will terminate when the door encounters an obstruction which prevents completion of the opening or closing cycle. 
     SUMMARY OF THE INVENTION 
     The present invention is embodied in a door controlling device for opening and closing a door in a wall. The device has a linkage having a first arm, one end of which is pivotally mounted by a pin to a bracket attached to the wall and the other end of which is pivotally attached to the second end of a second arm. The first end of the second arm is pivotally attached by a second pin to a second bracket mounted to the top of a door. The drive system for the device rotates one of the arms about the pin which joins the arm to its associated bracket to open or close the door. 
     The device includes a drive member which is connected by a gear train to a motor and which rotates about the pivot pin in one of the brackets. As the drive member turns around the pin it will engage the associated arm and force the arm to rotate through an open cycle or a close cycle. When the devise is not in use the drive member is in a stand-by position where it will not interfere with the movement of the arm while the door is being opened or closed. When the device is called upon to carry out a door open cycle, the motor and gear train rotate the drive member in one direction about the pivot pin and push the arm attached thereto to open the door. After the door has reached the fully open position, the motor will reverse direction and return the drive member to the stand-by position. When the devise is called upon to carry out a door close cycle, the motor and drive train will rotate the drive member in the opposite direction from the door open cycle, and after the door has reached the fully closed position, the motor will again reverse direction and return the drive member to the stand-by position. 
     The invention also includes a start means such as a switch or an infrared transmitter and receiver for starting an open cycle or a close cycle, a current measuring device for determining whether the motor is drawing an excessive amount of electric current, a door open detector for generating a signal when the door is in a fully opened position, a door closed detector for generating a signal when the door is in a fully closed position, and a stand-by detector for detecting when the drive member has returned to the stand-by condition. A control means, which is typically a computer, responds to the start means, the current measuring means, the door open detector, and the door closed detector, and the stand-by detector for directing current to the electric motor upon receipt of a signal from the start means, for reversing power to the motor to thereby reverse the direction of the motor upon receipt of a signal from the current measuring means, the door open detector or the door closed detector, and for terminating power to the motor on receipt of a signal from the stand-by detector. 
     The devise is entirely disengaged when the drive member is in the standby condition. When the device is carrying out a door open or a door close cycle, and the moving door contacts a foreign object such as a chair or a person&#39;s hand, the current measuring means will detect an increase in the current drawn by the electric motor in response to the resistance caused by the foreign object, and the control means will reverse the power to the electric motor and return the drive member to the stand-by position. 
    
    
     GENERAL DESCRIPTION OF THE DRAWINGS 
     A better understanding of the present invention can be had after a reading of the following detailed description taken in conjunction with the drawings in which; 
     FIG. 1 is a side elevational view of a door operating device in accordance with the present invention attached to a door which is in the closed position with portions thereof shown in phantom lines; 
     FIG. 2 is a top elevational view of the door operating device shown in FIG. 1 with the door in the closed position; 
     FIG. 3 is a top elevational view of the door operating device shown in FIG. 1 with the door in the open operating position; 
     FIG. 4 is an enlarged fragmentary side elevational view of the door opening device shown in FIG. 1; 
     FIG. 5 is a further enlarged fragmentary cross sectional view of the device shown in FIG. 1; 
     FIG. 6 is an enlarged fragmentary top view of the device as shown in FIG. 1 with the driven arm shown in solid lines in the door open position and shown in broken lines in the door closed position, and the driving member in the stand-by position; 
     FIG. 7 is a block diagram of the device shown in FIG. 1; 
     FIG. 8 is a top view of the drive member with the second arm removed; and 
     FIG. 9 is a top view of a second embodiment of a drive member for use with the door opening device shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIGS. 1,  2 ,  3 , and  4 , a door  10  having a door knob  11  is pivotally mounted about a horizontal axis on a plurality of pins, one of which  12 , is shown such that the door  10  opens and closes against a frame defining an opening  13  in a wall  14 . A door operating device  16  in accordance with the present invention has a first bracket  18  mounted above the door  10  and pivotally attached to the bracket  18  by a pin  20  is the first end  22  of an elongate first arm  24 . The second end  26  of the first arm  24  is pivotally attached to the second end  28  of a second arm  30  by a second pin  32 . The first end  34  of the second arm  30  is mounted on the distal end of a drive shaft  35  extending from a gear box  38  which is connected to a motor  40 . The gear box  38  and the motor  40  assembly are rigidly mounted on a horizontal portion  41  of a second bracket  42  which in turn is attached by screws or the like, not shown, to the top of the door  10 . 
     Referring to FIG. 5, the distal end  44  of the drive shaft  35  has a reduced diameter which extends through a hole in the horizontal portion  41  of the bracket  42  and through an aperture in the second arm  30 . The second arm  30  is pivotally retained to the distal end  44  of the shaft  35  by any suitable means such as a cotter pin  45  and washer  46  as shown. 
     Referring to FIGS. 5 and 6, fitted on the drive shaft  35  below the second arm  30  is drive member  47  having a lower tubular mounting portion  48  and a radially extending annular flange portion  49 . Fixed to the upper surface of the annular flange portion  49  near the outer edge thereof is an arcuate drive pin  50  having a first driving surface  52  and a second driving surface  54 . The tubular mounting portion  48  has diametrically opposing radial holes therein, which are aligned with a transverse hole in the drive shaft  35  and the mounting portion  48  is rotatably locked thereto by a pin  56  extending through the holes. 
     The motor  40  is reversible such that rotation of the motor  40  in one direction will cause the drive shaft  35  and the drive member  47  to rotate in one direction and rotation of the motor  40  in the opposite direction will cause drive shaft  35  and the drive member  47  to rotate in the opposite direction. 
     Referring to FIG. 6, when the devise is not in operation, the motor  40  and drive member  47  revert to a stand-by condition in which the drive pin  50  is in the stand-by position as shown. Energizing the motor  40  for rotation in the first direction will cause the shaft  35  and drive member  47  to rotate clockwise until the first drive surface  52  of the drive pin  50  engages a first side of the second arm  30 , after which the arm  30  and the shaft  35  will rotate together to the door close position shown in broken lines. On the other hand, energizing the motor  40  for rotation in the opposite second direction will cause drive member  47  to turn in the counter clockwise direction. Rotation of the drive member  47  will then cause the second drive surface  54  to engage the opposite side of the second arm  30  and rotate the arm  30  about the shaft  35  to the door open position shown in solid lines. Rotation of the second arm  30  about the shaft  35  in one direction will cause the door to move from a closed position shown in FIG. 2 to an open position shown in FIG. 3, and rotation of the arm  30  in the opposite direction about shaft  35  will cause the door to move from an open position shown in FIG. 3 to a closed position shown in FIG.  2 . 
     Referring to FIG. 7, to initiate a door opening or closing cycle, the invention includes a start means which may be a simple button operated switch  60  located near the door  10  or on a desk remote from the door. The start means can also include an infrared hand-held transmitter  62  and a receiver  64  attached to the wall  14  above the door  10  as shown in FIG.  1 . The device  16  also includes a door open detector  66  and a door close detector  68  for determining when the door has reached the fully open or fully closed condition, respectively. The door open detector and door closed detector may be simple switches positioned on the floor  67  or walls as shown in FIG. 3, so as to be actuated when the door reaches a fully open or fully closed condition or they may sense the angle of orientation of the first and second arms  24 ,  30 , respectively, as further described below. A stand-by detector  69 , which may be a simple limit switch as is further discussed below, is actuated when drive member  47  and the drive pin  50  are returned to the stand-by condition after the device  16  has been operated. 
     The circuit of the invention also includes a control means  70 , which may be a computer chip, and the control means  70  operates a relay or transistorized switches  74  and  75 , to connect or disconnect the electric motor  40  to a source of power for rotation in the first direction or the second direction respectively. The source of power may include a transformer  76  and a rectifier, not shown, for providing DC current suitable for a reversible electric motor  40 . 
     As shown in FIGS. 2 and 7, the circuit might also include a latch release  78  in the frame  13  of the door and an associated relay  79  for releasing the latch of the door at the commencement of the door opening cycle. Such electrically operated latch releases are commonly known in the art and are used to unlock the outer doors of apartment buildings by an occupant of an apartment in the build who seeks to admit a visitor. The latch release  78  is energized by the computer  70  at the beginning of a cycle to permit movement of the door  10  without turning the door knob  11  to open the associated latch. 
     The circuit further includes an obstruction sensing means  80  for sensing when an obstruction is preventing the motor  40  from opening or closing the door after a door closing or opening cycle has been commenced. In the preferred embodiment, the obstruction sensing means  80  is an ammeter and a comparator circuit of the type commonly known in the art which can be adjusted such that when the current drawn by the motor  40  exceeds the current normally required to move the door  10  through a cycle it will signal the computer  70  and the computer will reverse the direction of the motor  40 . 
     According to the invention, when the device is not in use the drive shaft  35  and the drive member  47  are in the stand-by position shown in FIG.  6 . When the drive member is in the stand-by position, the drive pin  50  will not obstruct the rotation of the second arm  30  about the shaft  35  during the normal opening and closing of the door  10 , and the door  10  may be opened or closed without resistance from the device  16 . 
     To operate the device  16  the start means  60  is actuated to commence either a door open cycle or a door close cycle. If the door open cycle is actuated, switch  74  is closed and the motor  40  rotates in one direction, and if the door close cycle is actuated switch  75  is closed and the motor  40  operates in the opposite direction. As the motor  40  rotates, the shaft  35  and the drive member  47  are turned causing one of the drive surfaces  52 ,  54  of the drive pin  50  to engage the second arm  30  and rotate the arm  30  to thereby open or close the door  10 . 
     When the door  10  reaches the fully open condition the door open detector  66  is actuated and when the door  10  reaches the fully closed condition the door closed detector  68  is actuated. On the actuation of either the door open detector  66  or the door closed detector  68 , the computer  70  will reverse the polarity of the power to the motor  40  and thereby cause the motor  40  to operate in the opposite direction. Reversing the direction of the motor  40  will cause the drive pin  50  to break contact with the second arm  30  and the door  10  will remain opened or remain closed while the drive pin  50  returns to the stand-by condition as shown in FIG.  6 . When the drive member  47  and the pin  50  reaches to the stand-by position, the stand-by detector  69  will be actuated and the computer  70  will terminate power to the motor  40 , and the device  16  will again be in the stand-by condition. 
     The device  16  will not interfere with the movement of the door until the start means, such as a switch  60  or the hand-held transmitter  62  is again actuated. If the movement of the door is obstructed during the operation of the device because a chair or a person is standing in the door&#39;s path, the obstruction sensing means  80  will detect the presence of the obstruction and the computer  70  will reverse the polarity of power to the motor  40  and the drive pin  50  will return to the stand-by condition as described above. 
     Referring to FIGS. 5 and 8, in the preferred embodiment, the flange  49  of the drive member  47  is a cam having a flat  82 . The flat  82  is engaged by a limit switch  84  when the drive member  47  is rotated to the stand-by position, such that the flat  82  and limit switch  84  form the stand-by detector  69 . 
     In the preferred embodiment, the door open sensor and the door closed sensor are not mounted on the floor and walls as are sensors  66  and  68  shown in FIG.  3 . Instead, when the angle of the arm  30  with respect to the mounting bracket  42  become oriented consistent with the door being in the closed condition, a door closed cam  86  mounted on the tubular portion  48  of the drive member  47 , has a protrusion  88  which engages a second limit switch  90  to signal the control means  70  to reverse power to the motor. Similarly, when the angle of the arm  30  with respect to the bracket  42  becomes oriented consistent with the door being opened, a door opened cam  92 , also mounted on tubular portion  48 , has a protrusion  94  which engages a third limit switch  96  to signal the control means  70  to reverse the direction of the motor. The limit switches  90 ,  96  both of which are mounted on the bracket  42 , and therefore, perform as the door closed detector and the door open detector respectively. 
     It should be appreciated that the cams  86  and  92  have non-circular bodies with a central opening which fits snuggly around the tubular portion  48  of the drive member  47  so as to not twist when the protrusions thereof engage the limit switches  90 ,  96  respectively, yet are not so snug that they cannot be turned manually. The door closed and door open detectors can then be adjusted by rotating cams  86 ,  92  respectively about the cylindrical portion  48 . 
     Referring to FIG. 9, the drive pin  50  may be configured as two spaced pins  150 ,  152  mounted on the annular flange  50  as shown. In this embodiment pin  150  has a surface which pushes the arm  30  when the motor  40  is operated in one direction and the pin  152  has a surface which pushes the arm  30  when the motor is operated in the opposite direction. 
     While the present invention has been described with respect to a single embodiment, it will be appreciated that many modifications and variations may be made without departing from the true spirit and scope of the invention. Therefore, it is the purpose of the appended claims to cover all such modifications and variations which fall within the true spirit and scope of the invention.