Abstract:
A traverse mechanism for a toothed ring member includes an interface at which modular actuators are attachable to drive a sprocket. The sprocket is selectively movable to a disengaged position wherein the sprocket does not engage the toothed ring member, thereby enabling the use of the traverse mechanism in the event of a malfunction.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to mechanisms for traversing a ring. 
       BACKGROUND 
       [0002]    Various military vehicles are characterized by a circular hole in the vehicle roof. A ring having teeth on its inner diameter at least partially defines the circular hole. A traverse mechanism is mounted with respect to the ring and includes a toothed member that is engaged with the teeth on the ring. The traverse mechanism supports an automatic firearm and causes the movement of the firearm about the periphery of the ring via rotation of the toothed member. 
       SUMMARY 
       [0003]    According to a first aspect of the disclosure, an apparatus for traversing a ring having a first plurality of teeth is provided. The apparatus includes a frame, a sprocket, and a drivetrain. The sprocket is rotatably mounted with respect to the frame and has a second plurality of teeth that are meshingly engageable with the first plurality of teeth. The drivetrain has an input member and is configured to transmit torque from the input member to the sprocket. The apparatus further includes a first fastening element that is mounted with respect to the frame and that is selectively, releasably engageable with a first complementary fastening element on a manual crank handle. The apparatus also includes a second fastening element that is mounted with respect to the frame and that is selectively, releasably engageable with a second complementary fastening element on a motor assembly having an output member. 
         [0004]    The apparatus is configured such that the manual crank handle and the input member are operatively connected for unitary rotation when the first fastening element is engaged with the first complementary fastening element; and is configured such that the output member is operatively connected to the input member for unitary rotation when the second fastening element is engaged with the second complementary fastening element. Accordingly, a user may select which actuator to employ to apply torque to the input device to drive the apparatus. 
         [0005]    According to a second aspect of the disclosure, an apparatus for traversing a ring having a first plurality of teeth includes a frame, a sprocket, and a drivetrain. The sprocket is rotatably mounted with respect to the frame and has a second plurality of teeth that are meshingly engageable with the first plurality of teeth. The drivetrain has an input member and is configured to transmit torque from the input member to the sprocket. 
         [0006]    A mounting member is operatively connected to the frame and is configured for operative attachment to the ring. The sprocket is selectively movable with respect to the mounting member between an engaged position in which the second plurality of teeth is engaged with the first plurality of teeth when the mounting member is operatively attached to the ring, and a disengaged position in which the second plurality of teeth is not engaged with the first plurality of teeth when the mounting member is operatively attached to the ring. 
         [0007]    Accordingly, the sprocket is selectively disengageable from ring in the event that the drivetrain malfunctions. The mounting member can maintain operative engagement with the ring even when the sprocket is disengaged from the ring, thereby allowing continued use of the apparatus to traverse the perimeter of the ring even if the drivetrain is jammed or otherwise malfunctioning. 
         [0008]    The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic, exploded, perspective view of a traverse mechanism having a sprocket, a disengagement lever, and a mounting member in accordance with the claimed invention; 
           [0010]      FIG. 2  is a schematic, perspective view of the traverse mechanism of  FIG. 1  with two modular actuators that are mountable to the traverse mechanism; 
           [0011]      FIG. 3  is a schematic, perspective view of the traverse mechanism of  FIG. 1  with an electric motor assembly mounted thereto; 
           [0012]      FIG. 4  is a schematic, perspective view of a ring member to which the traverse mechanism is mountable for traversal thereof; 
           [0013]      FIG. 5  is a schematic, perspective view of the traverse mechanism of  FIG. 1  with the sprocket in an engaged position with respect to the mounting member and the disengagement lever in a first position; 
           [0014]      FIG. 6  is a schematic, perspective view of the traverse mechanism of  FIG. 1  with the disengagement lever in a second position; 
           [0015]      FIG. 7  is a schematic, perspective view of the traverse mechanism of  FIG. 1  with the sprocket in a disengaged position with respect to the mounting member and the disengagement lever in the first position; 
           [0016]      FIG. 8  is a schematic, bottom view of the traverse mechanism of  FIG. 1  with the sprocket engaging the ring member of  FIG. 4 ; 
           [0017]      FIG. 9  is a schematic, bottom view of the traverse mechanism of  FIG. 1  with the sprocket disengaging the ring member of  FIG. 4 ; 
           [0018]      FIG. 10  is a schematic, top, cross-sectional view of an alternative sprocket for use with the traverse mechanism of  FIG. 1 ; and 
           [0019]      FIG. 11  is a schematic, side view of the sprocket of  FIG. 10 . 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Referring to  FIG. 1 , a traverse mechanism or apparatus  10  is schematically depicted. The traverse mechanism  10  includes a frame  14 . A toothed member, namely sprocket  18 , is rotatably mounted with respect to the frame  14 . More specifically, the frame  14  includes upper wall  22 , lower wall  26 , and side walls  30 ,  34  that cooperate to define a chamber  38 . Upper wall  22  defines a cylindrical hole  42  that extends therethrough. Lower wall  26  defines a cylindrical hole  46  that extends therethrough and that is vertically aligned with hole  42 . A first bushing  50  is inserted into hole  42  and a second bushing  54  is inserted into hole  46 . The bushings  50 ,  54  support a cylindrical shaft  58  therebetween. The sprocket  18  is mounted to the shaft  58  inside the chamber  38 . The shaft  58  and the sprocket  18  are selectively rotatable with respect to the frame  14 . A transparent shield  60  is mounted to the frame  14  to cover an opening to the chamber  38 . 
         [0021]    The apparatus  10  also includes a drivetrain  62  configured to transmit torque to the shaft  58  and the sprocket  18 . In the embodiment depicted, the drivetrain  62  includes a gearbox  66  having an input member  70 , an output member  74 , and gearing (not shown) inside a housing  78 . The gearing interconnects the input member  70  and the output member  74  such that torque applied to the input member  70  is transmitted to the output member  74 . In the embodiment depicted, the gearing is configured such that the output member  74  rotates about an axis that is generally perpendicular to the axis of rotation of the input member  70 . The gearing may also vary the speed ratio between the input member  70  and the output member  74 . 
         [0022]    The drivetrain  62  of the embodiment depicted further includes a chain drive mechanism  82  that transmits torque from the output member  74  to the shaft  58 . More specifically, the chain drive mechanism  82  includes a chain  84  that engages sprockets  86 ,  90 . Sprocket  86  is mounted to the output member  74  for rotation therewith. Sprocket  90  is mounted to the shaft  58  for rotation therewith. Accordingly, the drivetrain  62  is configured to transmit torque from the input member  70  to the sprocket  18 ; rotation of the input member  70  causes rotation of the shaft  58  and the sprocket  18 . A chain drive cover (shown at  92  in  FIG. 2 ) is mounted to the frame  14 . The chain drive cover  92  defines a cavity in which the chain drive mechanism  82  is disposed such that the chain drive mechanism  82  is between the cover  92  and the frame  14 . 
         [0023]    The apparatus  10  is mountable to a ring member (shown at  94  in  FIG. 4 ). Referring to  FIG. 4 , ring member  94  is characterized by a first plurality of teeth  98  formed on the inner diameter of the ring member  94 . The ring member  94  is mountable to the roof of a vehicle (not shown) such that the ring member  94  at least partially defines a circular hole in the roof through which an occupant of the vehicle may extend. Referring again to  FIG. 1 , the sprocket  18  defines a second plurality of teeth  102  that are meshingly engageable with the first plurality of teeth  98  such that rotation of the sprocket  18  causes the apparatus  10  to traverse the periphery of the ring member  94 . 
         [0024]    Thus, when the apparatus  10  is operatively connected to the ring member  94 , the apparatus is movable along the periphery of the ring member  94  by rotating the input member  70  with respect to the housing  78 . Referring to  FIG. 2 , wherein like reference numbers refer to like components from  FIG. 1 , the apparatus  10  includes an interface  106  at which at least two differently-configured actuators are fastenable for imparting torque to the input member  70 . In the embodiment depicted, the two different actuators are a manual crank handle  107  and a motor assembly  109 . 
         [0025]    More specifically, the interface  106  includes a first fastening element  110  that is mounted with respect to the frame  14  and that is selectively, releasably engageable with a first complementary fastening element  114  on the manual crank handle  107 . The apparatus  10  is configured such that the manual crank handle  107  and the input member  70  are operatively connected for unitary rotation when the first fastening element  110  is engaged with the first complementary fastening element  114 . In the embodiment depicted, the first fastening element  110  is a hole formed in the input member  70 , and the first complementary fastening element  114  is a pin that is extendable through the hole  110 , thereby fastening the crank handle  107  to the input member  70  for unitary rotation. 
         [0026]    The interface  106  includes a second fastening element  118 A mounted with respect to the frame  14  and that is selectively, releasably engageable with a second complementary fastening element  122 A on the electric motor assembly  109 . The electric motor assembly  109  includes a motor  126  having a selectively rotatable output member  130 . The apparatus  10  is configured such that the output member  130  is operatively connected to the input member  70  for unitary rotation when the second fastening element  118 A is engaged with the second complementary fastening element  122 A. 
         [0027]    In the embodiment depicted, the interface  106  includes a plurality of fastening elements  118 A-D that is releasably engageable with complementary fastening elements  122 A-D on the motor assembly  109 . Fastening elements  118 A-D are slots formed in the frame  114 . Complementary fastening elements  122 A-D are tabs or flat protrusions, extending from a mounting plate  134  to which the motor  126  and output member  130  are connected. Each of the tabs  122 A-D is engageable with a respective one of the slots  118 A-D, i.e., each of the tabs  122 A-D is insertable into a respective one of the slots  118 A-D. 
         [0028]    The frame defines a plurality of holes  138  that intersect the slots  118 A-D. Each of the tabs  122 A-D defines a respective hole  142 A-D. When the tabs  122 A-D are inserted into their respective slots  118 A-D, holes  142 A-D align with holes  138 , such that retention pins  146  are insertable through holes  138  and  142 A-D, as shown in  FIG. 3 , to retain the motor assembly  109  to the frame  14  and to retain the output member  130  in operative connection with the input member  70  for unitary rotation. 
         [0029]    The crank handle  107  is removable from the input member  70  by removing the pin  114  from hole  110  and pulling the handle  107  from the input member  70 . The motor assembly  109  is removable from the input member  70  by removing the pins  146  and pulling the assembly  109  such that the tabs  122 A-D are removed from the slots  118 A-D. Accordingly, a user of the apparatus  10  may select which of several actuators to employ to cause the apparatus  10  to traverse the ring  94 . 
         [0030]    The motor  126  applies torque to the output member  130 , which may be the rotor of the motor  126 , or which may be connected to the rotor, such as via gearing, to receive torque therefrom. The motor  126  may be electric, hydraulic, etc. within the scope of the claimed invention. 
         [0031]    The apparatus  10  further includes a mounting member  150  that is operatively connected to the frame  14 . More specifically, and with reference to  FIG. 1 , the frame  14  in the embodiment depicted defines a hole  154  at one end. The mounting member  150  defines two holes  158 ,  162 . Hole  154  is aligned with holes  158 ,  162 , and a hinge pin  166  extends through hole  154  and into holes  158 ,  162  such that the mounting member  150  is selectively rotatable with respect to the frame  14  about an axis (shown at A in  FIGS. 2-3  and  5 - 7 ), which is coextensive with the pin  166 . Thus, the sprocket  18 , being mounted with respect to the frame  14 , is selectively rotatable about axis A with respect to the mounting member  150 . The mounting member  150  is configured for attachment to the ring  94 . More specifically, the mounting member  150  is movably mounted to the ring  94 , such as via bearings (not shown), such that the mounting member  150  is slidable along the periphery of the ring  94 . Bushings  168  are employed to mount the pin  166  inside holes  154 ,  158 ,  162 . The mounting member  150  supports an automatic firearm (not shown). 
         [0032]    The sprocket  18  is selectively rotatable with respect to the mounting member  150  about axis A between an engaged position, as shown in  FIGS. 6 and 8 , and a disengaged position, as shown in  FIGS. 7 and 9 . In the engaged position, the sprocket  18  is positioned such that the second plurality of teeth  102  is meshingly engaged with the first plurality of teeth  98  when the mounting member  150  is operatively connected to the ring  94 , as shown in  FIG. 8 . In the disengaged position, the sprocket  18  is positioned such that the second plurality of teeth  102  is not engaged with the first plurality of teeth  98  when the mounting member  150  is operatively connected to the ring  94 , as shown in  FIG. 9 . 
         [0033]    More specifically, the sprocket  18  is rotatable with the frame  14  about axis A with respect to the mounting member  150  between the engaged and disengaged positions. Referring specifically to  FIG. 5 , the mounting member  150  at least partially defines a C-shaped opening  170 . A lever  174  is rotatably mounted with respect to the frame  14  and extends through the C-shaped opening  170 . The opening  170  includes a first segment  178 , a second segment  182 , and a third segment  186 . The first and third segments  178 ,  186  are generally parallel to one another and are generally parallel to the axis A. The second segment  182  is generally perpendicular to the axis A. Thus, when the lever  174  is in the first or third segments  178 ,  186 , physical part interference between the lever  174  and the edges of the opening  170  restrict or prevent rotation of the frame  14  and sprocket  18  with respect to the mounting member  150  about the axis A. 
         [0034]    The lever  174  is selectively rotatable with respect to the frame  14  between a first position, as shown in  FIGS. 2 ,  3 ,  5 , and  7 , and a second position, as shown in  FIG. 6 . Referring to  FIG. 5 , the lever  174  is shown in its first position and extends through the first segment  178  of opening  170 . Segment  178  is positioned such that the sprocket  18  is in its engaged position when the lever  174  extends therethrough. When the sprocket  18  is in its engaged position, the sprocket  18  extends through an aperture  190  formed in the mounting member  150  and into engagement with the teeth  98  of the ring  94 . The width of segment  178  is such that physical part interference between the lever  174  and the edges of segment  178  prevents the frame  14  and sprocket  18  from rotating about axis A, thereby maintaining meshing engagement between the sprocket  18  and the ring  94 . 
         [0035]    From the position shown in  FIG. 5 , the lever  174  is rotatable to its second position with respect to the frame, as shown in  FIG. 6 . Referring to  FIG. 6 , the lever  174  extends through segment  182 , thereby permitting rotation of the frame  14  and sprocket  18  about axis A such that the lever is in vertical alignment with the third segment  186  (as shown in phantom at  174 A) and the sprocket is in its disengaged position (as shown in phantom at  18 A). The lever  174  is then rotatable back to its first position, as shown in  FIG. 7 , with the lever  174  extending through the third segment  186 . The width of the third segment  186  is such that physical part interference between the lever  174  and the edges of segment  186  prevents the frame  14  and sprocket  18  from rotating about axis A, thereby maintaining the sprocket  18  out of engagement with the teeth  98  of the ring  94 . 
         [0036]    During normal operation, the sprocket  18  will be in the engaged position such that the apparatus traverses the ring member  94  as a result of torque applied to the input member  70 . However, in the event that there is a malfunction in the drivetrain  62 , e.g., if the chain drive mechanism  82  is jammed or the gearbox  66  breaks, the sprocket  18  is movable to the disengaged position so that the apparatus  10  can traverse the ring member  94 , such as by a manually applied force to the mounting member  150  or the firearm mounted thereon, without interference from the sprocket  18 . 
         [0037]    The lever  174  in the embodiment depicted is spring biased in its first position. The width of the first segment  178  is selectively adjustable. More specifically, and with reference to  FIGS. 1 and 7 , a plate  194  having a protuberant tab  198  is attached to the mounting member  150  via a plurality of fasteners  202  such that the protuberant tab  198  partially forms the C-shaped opening  170 , and, more specifically, extends between the first and third segments  178 ,  186 . The tab  198  defines a hole  204 . An adjustment member  206  defines an extended slot  210 . The member  206  is mounted to the tab  198  with a threaded fastener  214  that extends through the slot  210  and the hole  204 . The member  206  defines one edge of the first segment  178 , and is selectively movable with respect to the tab  198  such that the width of the first segment  178  is selectively variable. That is, the slot  210  enables the adjustability of the member  206  with respect to the tab  198  and the mounting member  150  to vary the width of the first segment  178  of the C-shaped opening  170 , thereby ensuring that the sprocket  18  remains in engagement with the teeth  98  of the ring  94  when the lever  174  is in the first segment  178 . 
         [0038]    Referring specifically to  FIG. 1 , the lever  174  includes a first portion  216  that is coextensive with the axis of rotation of the lever  174 , and that is at least partially contained within a concavity  218  formed in the frame  14 . The second portion  222  of the lever  174  is generally perpendicular to the first portion  214  and extends through the opening  170 . The frame  14  defines a concavity  226  that intersects concavity  218 , and that accommodates the second portion  222  when the lever  174  is in its first and second positions. A generally spherical knob  230  is mounted to one end of the second portion  222 . A plate  234  is mounted to the frame  14  to fasten the lever  174  thereto. The plate  234  defines a slot  238  through which the second portion  222  of the lever  174  extends. Threaded fasteners  242  extend through holes  246  in the plate  234  to mount the plate  234  to the frame  14 . 
         [0039]    Referring to  FIG. 10 , an alternative sprocket  248  is schematically depicted. Sprocket  248  is usable in place of sprocket  18  in  FIGS. 1-9 . Sprocket  248  includes a plurality of teeth  249  that are meshingly engageable with the first plurality of teeth shown at  98  on the ring member  94 . Instead of a circular hole in the center, as shown in sprocket  18  (see  FIG. 1 ), sprocket  248  defines a hole  250  having a rectangular keyway  254 . The sprocket  248  also defines a threaded hole  258  that extends from between two of the teeth  249  to the distal edge of the keyway  254 . Another threaded hole  262  extends from between two of the teeth  249  to the circular portion of hole  250 . Each threaded hole  258 ,  262  contains a respective set screw  264 . 
         [0040]    Referring to  FIG. 11 , wherein like reference numbers refer to like components from  FIG. 10 , the sprocket  248  is mounted to a shaft  265 . Shaft  265  is usable in place of the shaft shown at  58  in  FIG. 1 . Shaft  265  is generally cylindrical, and includes a rectangular key  266 . The shaft  265  extends through the hole  250  of the sprocket  248  such that the key  266  is disposed within the keyway  254 . The set screws  264  are manipulable to selectively alter the position of the sprocket  248  along the longitudinal axis of the shaft  265 , i.e., the height of the sprocket  248 . 
         [0041]    More specifically, during operation, the set screws  264  contact the shaft  265  and thereby prevent the sprocket  248  from sliding along the length of the shaft  265 . By loosening the screws, the sprocket  248  may slide along the shaft to a different position, such as the one shown in phantom at  248 A. Tightening the set screws will maintain the sprocket at the new position shown at  248 A. The ability to selectively alter the height of the sprocket  248  facilitates proper alignment of the sprocket  248  for meshing engagement with the teeth  98  of ring member  94 . 
         [0042]    While the best modes for carrying out the invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.