WO2001034931A2

WO2001034931A2 - Door drive system

Info

Publication number: WO2001034931A2
Application number: PCT/US2000/030856
Authority: WO
Inventors: Kevin E. Craig; John Puhlhorn; Mark C. Collins; Thomas M. Delucia
Original assignee: Raytheon Company
Priority date: 1999-11-11
Filing date: 2000-11-10
Publication date: 2001-05-17
Also published as: WO2001034931A3; WO2001034931B1; AU1480601A

Abstract

A door drive system for a sliding door includes a pair of pulleys; a drive belt on the pulleys; a drive shaft engaged with the drive belt; a rotary motor for rotating the drive shaft to translate the drive belt; and a door drive arm for mounting on a sliding door and interconnected with the drive belt for driving the sliding door between open and closed positions; and a door drive control system including a position sensor for sensing the position of the sliding door, a controller responsive to the position sensor for setting the speed, torque and acceleration of the motor in the opening and closing modes, and an obstruction detecting device for enabling the controller to interrupt motion of the sliding door in the opening and closing modes upon detection of an obstruction in the path of the sliding door.

Description

DOOR DRIVE SYSTEM

FIELD OF INVENTION

This invention relates to a door drive system, and more particularly to a door drive system for a sliding door for a vehicle.

BACKGROUND OF INVENTION Conventional sliding doors can be driven in a number of ways. In one approach a cable system is used to open and close the doors by selectively pulling and pushing the cable through a closed sleeve. One problem with this design is that it has limited useful life and the sleeve through which the cable moves can become clogged and contaminated. It is also subject to high wear due to the constant rubbing of the cable and sleeve. In another approach a pneumatic or hydraulic piston is used to operate the door. This too has problems. It is generally large, heavy and requires a cylinder/piston unit which is approximately the length of the door throw. It also has serious wear characteristics between the cylinder and piston and the pneumatic/hydraulic drive mechanisms are subject to potential seal failure and leakage. In yet another approach a ball screw mechanism is used. These are typically large and heavy and for longer door throws are subject to vibrations and whipping. They also require good protection against weather and ambient hazards: typically bellows or some other cover is used over the screw and ball but they have limited life. In still another approach a linkage mechanism is driven to expand and contract linearly to operate the door. Such linkages require substantial space to operate and have many moving parts and pivots subject to wear and misalignment.

BRIEF SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide an improved door drive system.

It is a further object of this invention to provide such an improved door drive system which is inexpensive, reliable, lightweight and serviceable.

It is a further object of this invention to provide such an improved door drive system which monitors the door positions.

It is a further object of this invention to provide such an improved door drive system which automatically unloads/unlocks the door in an emergency and prevents vehicle movement if the door is not closed and locked.

It is a further object of this invention to provide such an improved door drive system which interrupts door operation in the event of an obstruction.

It is a further object of this invention to provide such an improved door drive system with variable speed and acceleration.

The invention results from the realization that a reliable, safe, long life, and lightweight door drive system can be effected using a rotary motor and pulleys to translate a belt connected to a drive arm for operating a sliding door between open and closed positions and the further realization that an equally effective door drive control system can be achieved by sensing the door position and controlling the torque, speed and acceleration of the door in the opening and closing modes and using an obstruction detecting device to interrupt motion of the door in closing modes upon the presence of an obstruction.

This invention features a door drive system for a sliding door including a pair of pulleys, a drive belt on the pulleys, and a drive shaft engaged with the drive belt. There is a rotary motor for rotating the drive shaft to translate the drive belt and a door drive arm for mounting on the sliding door and interconnected with the drive belt for driving the sliding door between open and closed positions.

In a preferred embodiment the door drive arm may be mounted at substantially the center of gravity of the door. There may be a gear drive interconnecting the rotary motor in the drive shaft. There may be an idler pulley and a tensioning pulley for tensioning and directing the drive belt. The drive belt may be toothed. There may be a tensioning clamp having a clamp member for gripping each end of the drive belt and an adjustment member for moving at least one of the clamp members relative to the other for tensioning the drive belt. The clamp members may be mounted on and include the door drive arm. There may be an upper rail and a lower rail and a pair of spaced linear bearings for riding on each of the rails and interconnecting with the upper and lower portion of a sliding door. There may be an electrically powered locking device for securing the sliding door in the closed position and a passive actuating device for releasing the locking device upon an electrical power failure.

The invention also features a door drive control system for a sliding door including a door drive system having a motor for moving a sliding door between the open and closed positions, and a position sensor for sensing the position of the sliding door. A controller is responsive to the position sensor for setting the speed, torque and acceleration of the motor in the opening and closing modes. An obstruction detecting device enables the controller to interrupt motion of the sliding door in the opening and closing modes upon detection of an obstruction in the path of the sliding door.

The position sensor may include an encoder which monitors the position of the motor to determine the position of the sliding door. The controller may include a microprocessor. The obstructing detecting device may include a contact sensor. The contact sensor may be in the edge of the sliding door. The obstruction detecting device may include a presence sensor. The presence sensor may include an optical sensor and it may be a light curtain sensor. There may be a close sensor for detecting when the door is closed and a lock sensor for detecting when the door is locked. There may also be an electrically powered locking device for securing the sliding door in the closed position and a passive actuating device for releasing the locking device upon an electrical power failure.

The invention also features a door drive assembly including a pair of pulleys, a drive belt on the pulleys, and a drive shaft engaged with the drive belt. A rotary motor rotates the drive shaft to translate the drive belt and a door drive arm for mounting on a sliding door interconnects with the drive belt for driving the sliding door between the open and closed positions. A position sensor senses the position of the sliding door and a controller is responsive to the position sensor for setting the speed, torque and acceleration of the motor in the opening and closing modes. An obstruction detecting device enables the controller to interrupt motion of the sliding door in the opening and closing modes upon detection of an obstruction in the path of the sliding door.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:

Fig. 1 is a partially broken away three-dimensional view looking from the front top of a portion of a personal rapid transit vehicle showing door drive and door drive control systems according to this invention;

Fig. 2 is an enlarged detail three-dimensional view of a portion of the vehicle and systems of Figs. 1 looking from the rear;

Fig. 3 is an enlarged, diagrammatic top plan view of the belt drive of Figs. 1 and 2;

Fig. 4 is an enlarged, detailed, diagrammatic, three-dimensional view of the top of the door in the open position showing a light curtain obstruction detector and curtain sealing arrangements;

Fig. 5 is an enlarged diagrammatic sectional view of the seal of Figs. 4;

Fig. 6 is a functional block diagram of the door drive control system according to this invention;

Fig. 7 is an enlarged detailed diagrammatic three-dimensional sectional view of a portion of the upper guide rail assembly;

Fig. 8 is an enlarged detailed diagrammatic three-dimensional sectional view of a portion of the lower guide rail assembly; Fig. 9 is an enlarged detailed diagrammatic sectional view of the lower guide rail assembly and lower door seal;

Fig. 10 is an enlarged top sectional view of the door arm and belt tensioning drive of Figs. 1 and 2;

Fig. 11 is a front view of the adjusting block of Figs. 10; and

Fig. 12 is a diagrammatic view of the door lock mechanism of Fig. 2.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT There is shown in Fig. 1 a vehicle 10 such as a personal rapid transit vehicle which operates in a guideway including a body or cab 12 and a door 14. Such a vehicle and guideway system are shown and discussed in more detail in the following copending U.S. patent applications, filed on even date herewith: "Lateral Suspension Assembly for a Guided Vehicle System", by David C. Collins, Albert E. Lewis, and Gerald A. Garneau, Jr.; "In- Vehicle Switch Mechanism" by David C. Collins, Albert E. Lewis, and Gerald A. Garneau; "Passive Steering Assembly for a Guided Vehicle", by Robin Hossfield, John Puhlhorn, David C. Collins, and Marvin Fredburg; and "Vehicle Suspension System", by David C. Collins, Robin Hossfield and Joaquim A. Bento. Each of these applications is assigned to Raytheon Company and is incorporated herein by reference in its entirety.

Door 14 slides forward and backward between the closed and open position in the general direction of arrows 17. There is a lower guide rail assembly 16 which includes lower guide rail 18 that is fixed to the vehicle body or cab 12. A pair of spaced lower linear bearings 20 and 22 mounted on the door slidably engage rail 18. A second pair of upper spaced linear bearings 24 and 26 are mounted on the upper portion of door 14 and slide along upper guide rail 28 in the upper guide rail assembly 30. An elastomeric seal 32 extends along the front and top edge of door 14 to weather seal the door against cab 12. The seal is typically elastomeric and has contacts inside of it so that when seal 32 contacts an obstruction it collapses and closes its contacts and thereby provides a signal of the presence of an obstruction. Door 14 is driven in the closing and opening modes by a door drive arm 36 which attaches to the door at approximately its center of gravity CG so that the door moves smoothly without cocking or twisting. Door drive arm 36 is fixed to move with drive belt 38 which is driven by drive assembly 40 all of which is located in an equipment bay 42 covered by a plate, not shown.

Drive assembly 40, Fig. 2, includes a drive motor 50 and gear head 52. It also includes an encoder 54 which constantly monitors the position of door 14. Door 14 is shown in the closed position in full lines and the open position in phantom lines in Fig. 2. A fail safe door locking device 56 is used to lock door 14 in the closed position but release it automatically upon a failure of electrical power so that the door can be opened manually. Also located in bay or recess 42 is the lock sensor 58 and closed sensor 60 which are typically triple-redundant sensors.

Door drive system 62 is shown in more detail in Fig. 3 where it can be seen that drive belt 38 is a toothed drive belt as represented by the teeth 64 which engage with similar teeth on splined drive shaft or tooth gear 66 around which the belt is directed and tensioned by an idler pulley 68 and eccentric belt tensioning pulley 70. There are idler pulleys at each end 72, 74. The obstruction detection device includes a number of different sensors. For example, as shown in Fig. 4, seal 32 which wraps around door 14, is hollow and contains contacts which when the seal is crushed or pressed come together and provide a signal that an obstruction is present. The side part of the seal 32a abuts a sealing surface 80 under the side wall and roof 82 of cab 12. The upper portion 32b of seal 32a makes contact against sealing surface 84. The obstruction detecting device includes a second subsystem which typically uses an electromagnetic beam such as light, visible or invisible, or may even use ultrasonic or other acoustic waves to sense the presence of an object at the top of the door even before contact is made with the seal 32. For example, a light curtain assembly 90 may include a light source such as infrared light source 92 mounted underneath roof 82 which creates a light curtain directed across to infrared sensor 94, also mounted under the roof 82. A person whose shoulder, arm or head rises up through the door opening 96 would interrupt the light curtain 98 between source 92 and sensor 94 and provide a signal indicating an obstruction is present even before the seal 32 touched the person.

Seal 32, Fig. 5, is a two-part elastomeric component including a base 100 which mounts to the door and a removable and replaceable snap-in portion 102 which actually performs the sealing action against the sealing surfaces of the cab. Within that portion is a recess or cavity 104 in which is located a contact plate 106 and a contact button 108. Any pressure on seal 32 such as indicated by arrow 110 begins to collapse the upper portion 102 and bring contact plate 106 into proximity and then engagement with contact button 108. This closes the fail safe circuit and provides a signal indicating that an obstruction has been encountered. A door drive control system 120, Fig. 6, uses a controller 122 to receive position information 124 form encoder 54 engaged with the shaft of motor 50. This position information, in conjunction with a preprogrammed format in controller 122, provides the power 126 to motor 50 to control its speed, acceleration and torque dependent upon the particular position. For example, the door after unlocking will move quickly open and then de-accelerate to the full open position. When in the closing mode the door will accelerate quickly at first and then move slowly and smoothly so as to not endanger the passengers. If an obstruction is detected by the presence sensor 90 and/or the contact sensor 32 the door automatically returns to the open position. When it comes to the closed position, increased torque will be applied to seal the door tightly to the cab and facilitate locking. Controller 122 also responds to a number of other inputs. For example, it ceases operation when the closed sensor 58 indicates that the door is closed. The controller 122 also disables the contact sensor 32 to prevent the door from reversing to the open position. Controller 122 applies increased torque to secure the seal and allow the door to be locked. When the door is locked, lock sensor 60 provides an indication of that condition and the controller can then maintain a closing force on the door. At any time during the opening or the closing of the door, if the contact sensor 32, that is, the seal on the edge of the door, is collapsed by encountering an obstruction, the controller can interrupt the forward motion and even reverse the motion of the door. Likewise, if

presence sensor 90 determines that there is an obstruction present in its field of view, it too can send a signal to controller 122 which will stop or reverse the motion of door 14. In Fig. 7 with most of the door cut away, the view depicts the door in the closed position with seal 32 snugly engaged with sealing surface 84 and the rear linear bearing 26 at its forwardmost position on rail 28. Similarly in Fig. 8, linear bearing 22 attached to sliding door 14 is shown in its forwardmost or closed position on rail 18 of lower gui derail assembly 16.

Lower door seal 150, Fig. 9, is an elongated elastomeric member whose larger forward portion 152 functions as a wiper seal on the top surface 154 of lower guiderail assembly 16 of cab 12. Also shown quite clearly in Fig. 9 is the construction of each of the linear bearings as exemplified by linear bearing 22 which includes a housing 156 typically made of aluminum and a bearing material 158 which wraps around but does not completely surround the circular cross-section of rail 28. Housing 156 and bearing material 158 have an opening 160 at the lower end to accommodate the upright stand portion 162 of rail 18.

Toothed belt 38, Fig. 10, is actually a split belt arrangement in which one end 170 is held in position with clamp 172 by means of clamping screws only two of which, 174 and 176, are shown. Clamp 172 may have a series of teeth 171 which engage interstitially with teeth 64 on belt 38. A second clamp 178 which is adjustable also has teeth 173 which engage with teeth 64 on the other end 180 of belt 38. Clamp 178 is also held down by four screws only two of which, 182, 184, are visible in Fig. 10. The four screws engage with elongated slots 186, 188, 190, 192, to allow clamp 178 to move to and from clamp 172 and in this way draw the ends 170 and 180 of belt 38 closer to each other or farther from each other. This is done by means of an adjustment bolt 194 which has clearance through hole 196 in clamp 178 and is threadably engaged in bore 196 of clamp 172. The door drive arm forms the remainder of the belt tensioning clamp assembly.

Door drive arm 36, Fig. 10, also includes a magnet 200, Fig. 10, which forms a part of door close sensor 58. The presence of magnet 200 is sensed through triple- redundant sensors in head 202 such as three Hall effect sensors 204, 206 and 208 which sense the presence of magnet 200 when the door is in the fully closed position. The lock sensor 60, Fig. 12, includes a similar mechanism. The lock mechanism itself includes an arm 210 which is pivoted at 212. A drive actuator such as solenoid 214 is electrically operated to retract armature shaft 216 in the direction of arrow 218 in the lock mode. Subsequently the retraction of shaft 216 in the direction 218 causes lock detent 224 to move downwardly in the direction of arrow 226 and interface with the locking surface 228 on door drive arm 36. To release detent 24 from locking surface 24 and unlock the door, solenoid 214 is operated to drive shaft 216 in the opposite direction as indicated by arrow 230. At any time, if the electric power should fail so that solenoid 214 cannot operate, a fail safe device such as spring 232 or a substantial weight or mass 234 at the other end 236 of arm 210 will cause the arm to rock downwardly as indicated at arrow 238 and thereby automatically move lock detent 224 away from locking surface 228 and unlock the door in case of a power failure. The lock sensor 60 operates by means of a magnet 240 mounted on arm 210 and triple redundant sensors such as Hall effect sensors 242 which are

mounted in head 244. When arm 210 is in the locked position, as shown in Fig. 12, magnet 240 is centered beneath sensors 242 and the locked position indicating signal is generated. When the arm has been rocked to the unlocked position, either by the spring or weight or by the action of solenoid 214 so that it occupies the position shown in phantom at 210, magnet 240, also shown in phantom, will be remote from sensors 242 and so the lock signal will not be available.

Although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention.

Other embodiments will occur to those skilled in the art and are within the following claims:

What is claimed is:

Claims

CLAIMS A door drive system for a sliding door comprising: a pair of pulleys; a drive belt on said pulleys; a drive shaft engaged with said drive belt; a rotary motor for rotating said drive shaft to translate said drive belt; and a door drive arm for mounting on a sliding door and interconnected with said drive belt for driving the sliding door between open and closed positions.

2. The door drive system of claim 1 in which said door drive arm is mounted at substantially the center of gravity of the door.

3. The door drive system of claim 1 further including a gear drive interconnecting said rotary motor and said drive shaft.

4. The door drive system of claim 1 including an idler pulley and a tensioning pulley for tensioning and directing said drive belt.

5. The door drive system of claim 1 in which said drive belt is toothed.

6. The door drive system of claim 1 further including a belt tensioning clamp having a clamp member for gripping each end of said drive belt and an adjustment member for moving at least one of said clamp members relative to the other for tensioning said drive belt.

7. The door drive system of claim 1 in which said clamp members are mounted on and include said door drive arm.

8. The door drive system of claim 1 further including an upper rail and a lower rail, a pair of spaced linear bearings for riding on each of said rails and interconnecting with the upper and lower portion of a sliding door.

9. The door drive system of claim 1 further including an electrically powered locking device for sensing the sliding door in the closed position and a passive actuating device for releasing said locking device upon an electrical power failure.

10. A door drive control system for a sliding door comprising: a door drive system including a motor for moving a sliding door

between open and closed positions; a position sensor for sensing the position of the sliding door; a controller responsive to said position sensor for setting the speed, torque and acceleration of said motor in the opening and closing modes; and an obstruction detecting device for enabling said controller to interrupt motion of the sliding door in the opening and closing modes upon detection of an obstruction in the path of the sliding door.

11. The door drive control system of claim 10 in which said position sensor includes an encoder which monitors said motor to determine the position of the sliding door.

12. The door drive control system of claim 10 in which said controller includes a microprocessor.

13. The door drive control system of claim 10 in which said obstruction detecting device includes a contact sensor.

14. The door drive control system of claim 10 in which said contact sensor is in the edge of the sliding door.

15. The door drive control system of claim 10 in which said obstruction detecting device includes a presence sensor.

16. The door drive control system of claim 15 in which said presence sensor includes an optical sensor.

17. The door drive control system of claim 15 in which said presence sensor includes a light curtain sensor.

18. The door drive control system of claim 10 further including a close sensor for detecting when the door is closed.

19. The door drive control system of claim 10 further including a lock sensor for detecting when the door is locked.

20. The door drive control system of claim 10 further including an electrically powered locking device for securing the sliding door in the closed position and a passive actuating device for releasing said locking device upon an electrical power failure.

21. A door drive assembly comprising: a pair of pulleys; a drive belt on said pulleys; a drive shaft engaged with said drive belt; a rotary motor for rotating said drive shaft to translate said drive belt; a door drive arm for mounting on a sliding door and interconnected with said drive belt for driving the sliding door between open and closed positions; a position sensor for sensing the position of the sliding door; a controller responsive to said position sensor for setting the speed, torque and acceleration of said motor in the opening; and an obstruction detecting device for enabling said controller to interrupt motion of the sliding door in the opening and closing modes upon detection of an obstruction in the path of the sliding door.