Door drive and lock for a mass transit vehicle

Abstract: A power door operator (10,13) for mounting overhead of a door opening in a mass transit vehicle for moving a door panel (4,5) over and away from the door opening, including a base plate (18) incorporating a rotary helical drive (36) internal of a door hanger (21). The door panel (4,5) is locked in a closed position by primary and secondary means preventing drive rotation and panel movement.

Description: TO ALL WHOM IT MAY CONCERN: Be it known that I, Redreddy Sukumar Reddy, a citizen of India, residing at Evanston, Illinois, County of Cook, State of Illinois, have invented a certain new and useful power door operator having coaxial hanger and drive, of which the following is a specification. BACKGROUND OF THE INVENTION: This invention relates generally to car door operators for mass transit vehicles, more particularly concerning operators mounted overhead of a door opening in the vehicular side wall. The invention disclosed herein further relates particularly to power door operators incorporating helical drive/nut components and incorporating independent primary and secondary panel locks through prevention of drive member rotation and direct prevention of panel motion. Overhead door operators incorporating helical drive members are well known in the field of mass transit door equipment. U. S. Patents 3,745,705; 4,198,786; and 5,341,598 disclose overhead operators. All of the above mentioned operators utilize exposed helical door drive and exposed, axially displaced door hangers. In these arrangements there is a substantial force couple generated by offsetting the door drive and door hanger, thereby increasing wear on both the drive nut, hanger and any associated door panel lower guides. In addition, the physical displacement between the drive member and door hanger results in critical limited adjustment of the door panel with regard to motion transverse to the panel plane and hanger axis. Further, the exposed hanger and helical drive/nut combinations are particularly susceptible to contamination present in the application, including wear and dirt particles. Atmospheric corrosion is also a substantial problem. The invention disclosed herein largely overcomes the difficulties through the use of a coaxial design wherein the helical drive member is disposed internal of and coaxial with a semi-cylindrical door hanger. This arrangement minimizes the force couple generated by the drive member- door panel spacing or offset. In addition, the door hanger utilizes upper and lower plastic rollers operating on the corresponding surfaces of the semi-cylindrical hanger. This arrangement greatly reduces the criticality of transverse door adjustment. Also, a part of the invention disclosed herein is a greatly simplified door panel lock incorporating a ratchet cam and lock pawl combination which provides unidirectional rotation of the helical member. This allows precision positioning of the panel and prevents back driving the door panel through reverse rotation of the helix. The locking arrangement further includes a projection of the lock pawl through a slot or aperture in the door hanger whereby door panel opening motion due to a failure in engagement of the lock pawl and ratchet cam will be prevented by the continuing presence of the lock pawl in the aforementioned hanger slot. The design, therefore, provides truly independent primary and secondary door panel locks. Therefore, it is an object of the invention to provide an overhead power door drive having inherent primary and secondary door panel locks. It is an additional object of the invention to provide a power door drive having coaxial hanger and drive members minimizing door drive/door panel offsets and attendant wear producing forces. It is a further object of the invention to provide a power overhead door drive wherein the helical drive member is completely contained within a semi-cylindrical hanger, thereby minimizing environmental and atmospheric contamination of the helical drive/nut engagement. It is a further object of the invention to provide an overhead door drive wherein the coaxial relationship between a helical drive member internal of a semi-cylindrical door hanger utilizing cylindrically concave rollers intermediate the door panel and hanger surface provides simplified adjustment of the driven door panel. SUMMARY OF THE INVENTION: The door drive disclosed herein includes a base plate mounted overhead of an opening in the side wall of a mass transit vehicle. The base plate includes a semi-cylindrical door panel hanger portion. Mounted internal of the base plate hanger portion is a helical drive including a threaded cylindrical member and cooperating drive nut of the recirculating ball type. The helical drive member is rotated by a rotary prime mover mounted at one end of the base plate. The opposite end of the helical drive member is journaled internal of the hanger portion of the base plate in a cylindrical roller bearing. The drive nut extends through a longitudinal slot in the hanger portion of the base plate for reciprocal motion therein, on rotation of the rotary prime mover corresponding to said motion. A door bracket affixed to the upper end of a door panel is connected to the above mentioned drive nut extension. The door bracket further includes at least two sets longitudinally disposed vertically oriented pairs of cylindrically concave plastic rollers. The aforementioned vertical orientation provides upper and lower rollers in each pair. In operation, the upper and lower door bracket rollers cooperate with corresponding services in the semi- cylindrical hanger portion of the overhead mounted base plate, thereby providing low friction contamination resistant movement of the door panel when the rotary prime mover is energized and rotates the helical drive member. The combination provides reciprocal travel of the drive nut and attached door panel on the hanger portion of the base plate. Locking of the door panel in a closed position is accomplished through the use of a ratchet cam rotating on the helical drive member and an associated lock pawl. The lock pawl passes through an aperture in the above-described door bracket, contacting the ratchet cam such that only unidirectional rotation of the cam is allowed with the lock pawl in place. Therefore, with the door panel in a closed and locked position, the lock pawl occupies a position internal of a slot in the door panel bracket. In this condition the lock pawl and ratchet cam prevent rotation of the helical member which would allow panel movement in an opening direction on back driving of the drive nut and helical member. However, since the position of the lock pawl in the door panel bracket slot is independent of lock pawl/ratchet cam engagement, movement of the door panel in an opening direction should said engagement fail, continues to be prevented. The above described combination of lock pawl/ratchet cam and location of the lock pawl provide separate and distinct primary and secondary locks for the door panel in that a failure of the ratchet cam/lock pawl engagement or other failure allowing rotation of the helical drive member with attendant motion in the opened direction of the door panel is prevented by the presence of the lock pawl in the door bracket slot. BRIEF DESCRIPTION OF THE DRAWINGS: Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings in which: Figure 1 is a partial perspective view of a typical transit car body, particularly showing location of the operators of the invention in place overhead of reciprocating car door panels; Figure 2 is a partial perspective view of one operator shown in Figure 1, particularly showing location of the door panels, and other operative components of the power door drive through cut-away views; Figure 3 is a partial perspective view of the lock pawl and ratchet cam utilized in the invention, and, as indicated in the dashed circle of Figure 2 and identified by numeral 3; Figure 4 is an exploded view of the drive members, lock shaft, lock panel, and door bracket of the invention. Figure 5 is a further partial perspective view of the operator of the invention including a tearaway view of the drive member and drive nut, and particularly showing the opposite side of the operator of Figure 2; Figure 6 is a partial plan view of the operator of the invention, particularly showing the lock shaft and lock members. Figure 7 is a section of the operator of the invention the along lines 7-7 of Figure 6; Figure 8 is a section of the operator of the invention along the lines 8-8 of Figure 6; Figure 9 is a section of the operator of the invention along the lines 9-9 of Figure 6; Figure 10 is a partial section of the operator of the invention particularly showing end view of the lock and unlock cams; Figure 11 is a view along the lines 11-11 of Figure 10, particularly showing a plan view of the lock cam and lock shaft of the invention; Figure 12 is an additional partial section of the lock assembly of the invention, particularly showing the position of a lock pawl in an unlocked position; Figure 13 is a partial plan view of the lock assembly of the invention, particularly showing the lock shaft pawl and lock cam with the door in a partially closed position; Figure 14 is a partial section of the lock assembly of the invention corresponding to the door position of Figure 13; Figure 15 is a partial plan view of the lock assembly of the invention, particularly showing the door in a fully closed position; Figure 16 is an additional partial section of the lock assembly of the invention with the panel as shown in Figure 15; Figure 17 is a partial section of the invention, particularly showing the manual unlocking assembly of the invention, particularly showing the lock shaft in a manually unlocked position; Figure 18 is an additional plan view of the manual unlock assembly of Figure 17; and Figure 19 is a partial perspective view of the drive system of the invention, particularly showing the rotary drive member, shaft coupler between the rotary prime mover and the helical drive member and the lock pawl/ratchet cam in engagement. While the novel concentric overhead power door actuator of the invention will be described in connection with a preferred embodiment and a single alternate embodiment, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents that may be included within the spirit and scope of the invention disclosed and defined by the appended claims. DETAILED DESCRIPTION OF OPERATION: With respect to Figure 1, there is shown a partial view of a "typical transit vehicle having bi-parting doors 4 and 5 having covered windows 6 and 7 driven by power operators 10 and 13 for reciprocal motion over and away from an opening 2 in car 1. Mounted overhead of door panels 4 and 5, operators 10 and 13 provide the above-mentioned reciprocal motion. As operators 10 and 13 are identical, the following description will be concerned with operator 13 as those skilled in the art will readily understand that operation of operator assembly 10 is identical other than the direction of motion. Operator 13 includes a base and hanger assembly 16 having a base portion 18 and a hanger portion 21. Hanger portion 21 includes an internal cavity 23 and a longitudinal slot 20. Surrounding the internal cavity 23 of the hanger portion 21 there are upper and lower hanger surfaces 22 and 25, respectively. As shown in Figures 7 and 8, the base plate 16 mounts in housing 12 attached to car member 11. Helical drive member 36 is rotatably mounted in cavity 23 using drive motor 37 at one end coupled to helical member 36 via coupler 38. The distal end of helical member 36 is supported by outboard cylindrical roller bearing 39 journaled internal of the cavity 23 (not shown). Drive nut 40 (Reference Figure 5) may be of the well known recirculated "ball nut type mounted on drive member 36 for reciprocal motion along said drive member on rotation thereof. The cavity 23 of hanger portion 21 of the base plate 18 further includes a longitudinal slot 20. Nut 40 includes a protrusion 43 extending through the slot 20. Protrusion 43 is affixed to the panel bracket 17 portion of hanger assembly 28. Turning now to Figures 2, 5 and 7, the hanger assembly 28 carrying the door panel 4 includes upper rollers 31 and lower rollers 34 rotatably attached to the panel bracket 17. Rollers 31 and 34 cooperate with surfaces 22 and 25 in providing motion along the hanger portion 21 of base plate 16. Protrusion 43 of drive nut 40 extends through slot 20 and is attached to panel bracket 17 intermediate the attachment points of rollers 31 and 34 (Reference Figures 5 and 7). Motion of drive nut 40 attached to door bracket 17 via protrusion 42 moves the door panel 4 on rotation of helical member 36. In further reference to Figures 4 and 6, lock shaft assembly 53 is rotatably attached to the internal surface of the upper portion 18 of base plate 16. Mounting of assembly 53 is accomplished by journaling the shaft 56 in journals 59 for rotatably motion therein. Also attached to shaft 56 is lock pawl 49, unlock tab 62, and lock cam 65, as shown. The shaft 56 is maintained in a counterclockwise position by torsion spring 60. The combination of spring 60 and lock pawl 49 when occupying slot 44 in hanger 17, cooperating with ratchet cam 45, provide unidirectional rotation of helical shaft 36, thereby preventing clockwise rotation of helical shaft 36. Operation of ratchet cam 45 and lock pawl 49 could be achieved through use of a unidirectional clutch. Also attached to the upper inner surface of base assembly 16 is lock panel assembly 71 including lock panel 75 (Reference Figures 4 and 7). In position, lock panel 75 carries unlock solenoid 74, lock cam 68, panel sensor 72 and manual unlock assembly 77. The operation of this panel will be described further in substantial detail. In operation, rotation of helical member 36 by drive motor 37 moves drive nut 40 in a direction dependent on the rotation of member 36. The following description will assume that the door panel is in a closed and locked position, as shown in Figure 6. Operation of the novel lock shaft configuration 53 is best seen with reference to Figures 10 through 16. In the closed and locked position, lock cam 68 biased by spring 70 has allowed lock shaft 56 to assume a somewhat counterclockwise position wherein lock pawl 49 and ratchet 45 are in a 4ondition shown in Figures 3, 5 and 16, whereby further rotation in a clockwise (door opening) direction is prevented by the interaction of ratchet cam 45 and lock pawl 49. Lock pawl 49, lodged in aperture 44 in door hanger 17, further prevents motion of door panel 5. As shown in Figures 15 and 16, lock cam 68 pivoted at 69 is biased counterclockwise by spring 70. With the pin 42 in a door closed position, cam 68 and lock shaft cam 65 are disengaged (Reference Figure 15). On receipt of a door open command, solenoid 74 is energized raising the solenoid plunger 76, contacting tab 62, thereby rotating shaft 56 in a counterclockwise direction, as shown in Figure 10. Rotation of shaft 56 raises cam 65, thereby withdrawing lock pawl 49 from slot 50 in panel bracket 17 (Reference Figure 12). Separation of lock pawl 49 and ratchet cam 45 unlocks the ratchet cam 45, allowing helical shaft 36 to rotate in a clockwise direction. The position of lock pawl 49 is sensed by projection 52 and sensor 51, thereby energizing drive motor 37, rotating helical member 36 in a clockwise direction. Rotation of member 36 moves drive nut 40 and door panel 5 to an opened position. Operation from a fully opened position to closed and locked proceeds as follows: With particular reference to Figures 10 through 16. With the door in a fully opened position, cam 68 is in the position shown in Figure 11 wherein cam 68 has contacted lock cam 65, thereby rotating lock shaft 56 counterclockwise. In this condition, lock pawl 49 is rolled out of engagement with ratchet pawl 45 and outside of slot 50 as shown in Figure 12. To initiate a closing cycle, drive motor 37 rotates helical drive member 36 in a clockwise direction thereby moving door bracket 42 toward the fully closed position. When pin 47 attached to bracket 42 reaches the lower portion of lock cam 68, lock elements are as shown in Figure 11. Further movement of lock pin 47 rotates lock cam 68 in a clockwise direction due to the novel spatial relationship between lock pawl 49, lock shaft cam 65 and hanger slot 44, as signaled by panel sensing switch 72, and panel bracket 73, motion of door panel bracket aligns slot 44 and lock pawl 49. Rotation of lock shaft 56 simultaneously allows lock pawl 49 to enter slot 44, and engage ratchet cam 45. At this point, both the primary lock, i.e., lock pawl 49 and ratchet cam 45, and the secondary lock, i.e., lock pawl 49 in slot 44, are engaged, as shown in the progression of Figures 13, 14, 15 and 16. Movement of lock pawl 49 into slot 50 is detected by sensor 51 as is the location of panel bracket 42 by sensor 72 and tab 73. Those skilled in the art will readily see that with the lock pawl 49 in slot 50 and held against ratchet cam 45, the door panel 5 is held in a closed position, requiring two consecutive failures, i.e., a failure of the ratchet cam 45 and lock pawl 49 acting in slot 50 to allow unauthorized door opening. This novel approach provides primary and secondary door panel locks in a single package, providing an extraordinarily high level of reliability in the locked position. Operation of the manual unlocking assembly 77 proceeds as follows. With the door in the above described closed and locked position, in the case of loss of power, manual unlocking is achieved by downward force on lever 81, thereby rotating cam 79 against toggle spring 83. Rotation of manual unlock cam 79 in a counterclockwise direction contacts unlock cam 65, rotating shaft 56, thereby moving lock pawl 49 out of engagement with lock ratchet 45 and slot 50 in hanger bracket 17. At this point, the door can manually be moved to an opened position. Thus, it is apparent that there has been provided in accordance with the invention a linear overhead power door operator having a semi-cylindrical hanger and an internally mounted coaxial door drive member that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with a specific embodiment thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace any and all such alternatives, modifications and variations as may fall within the spirit and broad scope of the appended claims. What is claimed as new and desired to be secured by Letters Patent of the United States is:

Claims: A door operator (10,13) for a mass transit vehicle comprising: an operator base plate (16) mounted overhead of a doorway (2) in a vehicle (1); a door hanger (21) on said base plate, on which a door panel (4) is mounted for motion therealong, said motion moving said panel over and away from said doorway; a door drive (36,37) internal (23) said hanger; means (37) powering said door drive; and means (40,43) attaching said panel and door drive, wherein powering said door drive moves said panel (4). A power door operator (10,13) mounted over overhead of a door opening (2) in the body of a passenger vehicle (1) for moving a door panel (4,5) over and away from said opening comprising: a hanger (21) mounted on said vehicle body, said hanger extending over said opening and having a cavity (23) defined by concentric inner and outer surfaces and a side wall therebetween and a door panel being mounted on said hanger for movement therealong, whereby said door panel has an upper edge and whereby a door support (17) is provided on said panel upper edge, said support extending above said panel and adjacent to said hanger; means on said support intermediate said support and hanger outer surface providing movement of said panel along said hanger (21); a longitudinal slot (20) in said hanger side wall; drive means (43) in said cavity, said drive traversing said longitudinal slot; means selectively controlling said drive means for reciprocal traverse of said slot; means on said drive means extending outwardly through said slot; means connecting said door support and outwardly extending drive means; wherein said selectively controlled movement of said drive means along said slot moves said panel over and away from said car body opening. The operator of claim 1 wherein said hanger and door support further comprise: a semi-cylindrical, longitudinally disposed member; a bracket having upper and lower ends attached to said panel at said upper end; at least two pair of vertically spaced, cylindrically convex rollers attached to said bracket upper end, said rollers disposed axially transverse to said cylindrical member, and spaced there along; wherein said cylindrical hanger and door support rollers provide door panel movement along said hanger. The operator of claim 1 wherein said drive means further comprises: a longitudinally disposed helically grooved shaft; drive means rotating said shaft; a moving member cooperating with said shaft grooves for providing reciprocal motion of said member along said shaft upon rotation thereof, thereby moving said panel; means attaching said moving member and door bracket; whereby shaft rotation moves said panel over and away from said car body opening. The operator of claim 3 wherein said drive means further comprises: coupling means intermediate said drive means and said helically grooved shaft; means in said coupling means providing selective unidirectional rotation of said shaft, said unidirectional rotation moving said panel to a position over said car body opening; means actuating said selective means when said panel is positioned over said car body opening; whereby on actuation of said selective means, said coupling means prevents door panel motion away from said car body opening. The operator of claim 4 further comprising: means in said upper panel bracket, said panel bracket means coacting with said coupling means, said panel bracket means and selective coupling means retaining said panel in said position over said car body opening. A lock operable by a power door operator for maintaining a door panel (4) in closed position over an opening (2) in a car body said door operator comprising : a door hanger (21) mounted overhead of said opening, whereby a door panel (4) is mounted on said hanger (21) for reciprocal movement thereon, said panel mounting including a door panel bracket (17) attached to said the upper end of said panel; door drive means (36,37) internal said hanger, said drive means including a rotary helical drive member (36) having a cooperating drive nut (40) providing reciprocal motion on rotation of said helical member; means (42) attaching said drive nut (40) and panel bracket; (17) a rotary drive motor in said drive means; said lock comprising : unidirectional drive means intermediate said drive motor and helical member, said drive means selectively actuable when said panel is in a position over said opening; means in said door panel bracket coacting with said unidirectional means when in an actuated condition for preventing door panel movement away from said opening; whereby said panel is locked into a position over said opening. In combination, an overhead power door operator for moving a door panel from open to closed and closed to open positions over a door opening in a mass transit vehicle and a door lock for holding said panel in a closed position comprising: an operator base plate (16) having a door hanger portion (21) mounted overhead and across said opening, whereby a door panel is mounted on said hanger for reciprocal movement thereon a cavity (23) in said hanger; a longitudinal slot (20) in said cavity; a helical door drive (36,37) mounted and journaled in said cavity (23) for rotation therein, said drive having a rotary helical threaded shaft (36) and cooperating ball nut (40), said ball nut extending through said slot; drive means (37) on said base plate; means (43) coupling said drive means and helical member; a bracket on said door panel, said bracket mounted on said hanger for motion therealong; means attaching said bracket and ball nut wherein rotation of said helical member by said drive means moves said door panel to a closed position over said opening; means on said base plate and helical drive providing unidirectional rotation of said helical member on movement of said door to a closed position; means on said door bracket coacting with said unidirectional means for retaining said panel in a closed position; whereby door panel movement from a closed position is prevented. The combination of claim 7 wherein said unidirectional means comprise: a ratchet cam on said helical drive; and a lock pawl on said base plate, said lock pawl mounted for pivotal motion around a first end, and a lock latch defined by said second end wherein said latch end engages said ratchet cam providing unidirectional rotation of said helical drive. The combination of claim 8 wherein said door bracket means comprise: a slot in aid door bracket mounted on said base plate; wherein in a door closed position, said lock pawl enters said slot, thereby preventing door panel movement away from said door closed position.

Inventors: REDDY REDREDDY SUKUMAR, REDDY, REDREDDY SUKUMAR
Applicants: WESTINGHOUSE AIR BRAKE CO, WESTINGHOUSE AIR BRAKE COMPANY
Application year: 1997
Main classification: B61D19
IPC codes: E05F15, B61D19, E05F11