Abstract:
Apparatus for the selective engagement and disengagement of a ring gear of a gear set in which an actuator can be displaced between a first position engaging the ring gear and a second position disengaged from the ring gear selectively by a manually operable mechanical arrangement or a fluid pressure arrangement without altering or adding to the housing or control device of the gear set. The mechanical arrangement and the fluid pressure arrangements are integrated so that the operation of the actuator can be selectively achieved either by the mechanical or fluid arrangement.

Description:
FIELD OF THE INVENTION 
   The invention relates to apparatus for selective engagement and disengagement of a gear set. 
   More particularly, the apparatus is adapted for controlling the engagement and disengagement of a gear set selectively control the operation of a transmission for driving a winch or other gear driven device. 
   The invention further relates to a method for selectively engaging and disengaging the gear set and thus for enabling or disabling the transmission. 
   BACKGROUND OF THE INVENTION 
   In a conventional system for driving a winch or other gear driven device a gear set is engaged to drive the winch and a number of disengagement devices are known to disengage the gear set. In one such disengagement device, the ring gear of the gear set is released from driving the other gears and is allowed to turn freely with the rest of the gear set. 
   In this known device, a pin is used to secure the ring gear in place. This allows the other gears to drive against the ring gear and produce the necessary torque to drive the gear set. To disengage the gear set, the ring gear is allowed to turn freely with the rest of the gear set by pulling the pin out of engagement with the ring gear. The pin is normally activated by a handle attached to the opposite end of the pin that is engaged with the ring gear. The pin is supported for axial travel in a housing between the engagement and disengagement positions. When the handle is actuated, the pin is pulled to the disengagement position and the ring gear is set free. 
   Sometimes a fluid is used in place of the handle to disengage the ring gear. In this case, the housing for the handle is replaced with a different housing that allows the fluid to activate the pin, in the same manner as the handle, allowing the pin to slide axially back and forth between the engagement and disengagement positions. It is also known to attach a cylinder externally on the housing of the winch to achieve the same effect. When the fluid is supplied to the cylinder, it pulls the pin to the disengagement position, which in turn releases the ring gear to turn freely with the rest of the gears. 
   In both cases, when the handle or fluid is released, the pin is forced back to the engagement position by a spring acting on the pin. 
   SUMMARY OF THE INVENTION 
   An object of the invention is to provide a device which permits engagement and disengagement of a gear set selectively by a manual operation of a handle or by a pressurized fluid without altering or changing the housing or adding components to the device. 
   A feature of the invention is that it provides a choice of manual or fluid disengagement utilizing the same housing and a control device without the need of supplying separate parts for manual or fluid disengagement of the gear set. Hence, the same parts operate for either manual or fluid operation. 
   In accordance with the invention, the apparatus comprises a control device including an actuator which is supported in a housing containing the gear set. The actuator is biased by a spring to an engaged position in which the ring gear of the gear set is blocked against rotation thereby enabling the gear set to transmit drive to the driven device. The control device has a mechanical arrangement by which the actuator can be displaced to a disengaged position from the ring gear and the control device incorporates a fluid-operated arrangement by which the actuator can be disengaged from the ring gear. The mechanical and fluid arrangements are integrated in the control device such that operation of the actuator can be selectively achieved by one or the other of these arrangements using the same housing and without any addition or change of component parts. 
   The invention is also directed to a method by which the selective activation of the ring gear to control the gear set is achieved by mechanical or fluid operation by connecting a control device to a housing of a gear set. 
   The invention is also directed to the control device itself which integrates both mechanical and fluid arrangements such that the mechanical and fluid are separately operable when the control device is connected to the housing containing the gear set to selectively engage or disengage the ring gear in the gear set and thereby control transmission of drive by the gear set to the winch or similar device. 

   
     BRIEF DESCRIPTION OF THE FIGURES OF THE DRAWING 
       FIG. 1  is a perspective view of a control device according to the invention adapted for assembly with the main support of a winch or other gear driven device. 
       FIG. 2  is a cross-sectional view of the control device assembled with a portion of the main support of the winch or other gear driven device in an engaged state. 
       FIG. 3  is a cross-sectional view similar to  FIG. 2  showing the control device in a disengaged state obtained by a manual operation. 
       FIG. 4  is a cross-sectional view similar to  FIG. 3  in which the control device is in a disengaged state obtained by a fluid operation. 
       FIG. 5  is a cross-sectional view similar to  FIG. 3  showing how the control device is moved to the engaged position by the manual operation. 
       FIG. 6  is a cross-sectional view similar to  FIG. 4  showing the control device in the engaged position and prepared for disengagement by the fluid operation. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1  of the drawing, therein is seen a transmission  1  adapted for delivering power from a drive source (not shown) to a driven unit (not shown) such as a winch or other gear driven device The transmission incorporates a gear set G (partially shown in  FIG. 2 ) which includes a ring gear  2  ( FIG. 2 ) which is rotatably supported in a housing  3  of the transmission. The ring gear  2  is connected in the rest of the gear set so that when the ring gear  2  is free to rotate, the transmission will be free-wheeling and will not transmit drive from the drive source to the driven unit. However, when the ring gear is blocked from rotating, the gear set is active to transmit drive to the drive unit from the driven source. 
   The details of the construction of the transmission  1  are not germane to the invention and will not be described in greater detail. 
   In accordance with the invention, a control device  10  is provided to selectively engage and disengage the ring gear  2  in order to enable and disable the transmission  1 . 
   A feature of the invention is that the control device  10  can be selectively operated either mechanically or by pressurized fluid. This will be explained more fully later. 
   The control device  10  includes a barrel or casing  11  which can be inserted into a bore  12  in the housing  3  of the transmission. The barrel is secured in the housing by a set screw  13  or other method. 
   Referring to  FIG. 2 , therein it is seen that the control device  10  includes a plunger or actuator  14  adapted to engage or disengage in a hole  15  in ring gear  2  to selectively block free rotation of the ring gear. As previously indicated, the ring gear  2  enables selective drive of the transmission depending on whether the actuator  14  is engaged in hole  15  in the ring gear or disengaged from the hole  15 . 
   A number of holes  15  are disposed circumferentially in the ring gear although only one is shown. The actuator  14  is supported in barrel  11  for axial slidable travel to engage in or disengage from the hole  15  in ring gear  2 . The barrel  11  and the actuator  14  are of cylindrical shape and are preferably made of steel. 
   The actuator  14  has holes  9  cross-drilled therein to enable supply of a lubricant and to avoid creation of a vacuum in hole  12  in the housing. The actuator  14  is sealed in barrel  11  by o-rings  16  and  17 . The barrel  11  is externally sealed in housing  3  by o-rings  18  and  19 . 
   A removable vent  20  is inserted in a bore  21  in housing  3 . The bore  21  is connected by a port  29  to an annular chamber  22  (best seen in  FIG. 4 ) defined between o-ring  16  and o-ring  24  inside barrel  11 . A coil spring  25  acts between the actuator  14  and the barrel  11  to push the actuator  14  into an engaged position in the hole  15  of the ring gear  2 .  FIG. 2  shows the engaged position of the actuator and the ring gear. In this position, the ring gear  2  is blocked from rotating and the transmission  1  can deliver drive to the driven unit. 
   A handle  30 , in the form of a lever, is connected by a spring-biased pin  31  to an end of the actuator  14  and when the actuator is to be disengaged from the ring gear by a mechanical operation, the handle  30  is angularly moved from the position shown in  FIG. 2  to the position shown in FIG.  3 . This causes the actuator  14  to retract from the hole  5  in the ring gear  2  whereby the ring gear is set free for rotation with the rest of the gear set and the transmission is free-wheeling and will not transmit drive to the driven unit. The lever  30  includes a pair of wings or gussets  32  which support the ends of pin  31 . The handle design is not part of the invention. The wings or gussets  32  are formed with rounded end faces  33  which ride on an end face  34  of the housing when the lever  30  is turned thereby producing axial translation of the actuator. Consequently, when the lever  30  is raised to its position of disengagement as shown in  FIG. 3  the actuator will be retracted from the ring gear  2  and while compress spring  25 . The actuator is thus brought to the disengaged position by a mechanical operation of raising the lever to the position shown in FIG.  3 . The compressed spring  25 , bears against o-ring  17  which is held in place by a spacer  36  and a retainer ring  37 . When the lever is released, the spring  25  will return the actuator  14  to its engaged position with the ring gear. The handle can be of any form and attached by any means as long as it is capable of moving actuator  14  to the disengaged position. 
   It is again noted that in the disengagement position of  FIG. 3 , the actuator is removed from the engagement hole in the ring gear  2  to allow the ring gear to rotate freely with the other gears in the gear set. This enables the gear set to rotate freely inside the housing  3  without driving the winch or similar driven element. 
   In order to engage the actuator  14  in the hole  15  of the ring gear  2 , the handle  30  is released and spring  25  displaces the actuator  14  to the position shown in  FIG. 2  in which the actuator is forced into the hole  15  in the ring gear  2  thereby blocking rotation of the ring gear and activating the drive of transmission  1 . 
   The actuator  14  can also be moved selectively by a fluid pressure arrangement instead of by the manual arrangement previously described. 
   In this regard and with reference to  FIG. 5 , the actuator  14  is in the engaged position in readiness for a fluid pressure operation by which actuator  14  will be retracted from the ring gear by a pressurized fluid. The pressurized fluid can be a liquid or a gas. In order to achieve retraction of the actuator  14 , the vent  20  is removed from bore  21  and pressurized fluid is introduced through the opening  21  into the annular chamber  22  to compress spring  25  (as shown in  FIG. 4 ) against o-ring  17  which is held in place by spacer  36  and retainer ring  37 . The actuator  14  is held in the disengaged position by the constant pressure of the fluid. In the disengaged position, the actuator is pulled out of the engagement hole  15  in ring gear  2  and the ring gear is free to rotate with the other gears in the gear set so that the transmission will not transmit drive power to the winch or other gear driven device. 
   In order to bring the actuator into the engaged position in the hole in the ring gear, the supply of pressurized fluid to the opening  21  is halted and spring  25  will return the actuator  14  to the engaged position in hole  15  in the ring gear  2 . 
   In accordance with the description herein, the control device  10  operates either mechanically or by fluid pressure to engage or disengage the actuator and the ring gear. This is achieved without changing the housing  11  when the device is to be used in the fluid pressure operation. All that is required is to remove the vent  20  to enable introduction of the pressurized fluid whereas when the control device  10  is used manually the vent  20  is inserted into the opening  21 . 
   It is preferred that the winch or other gear driven device not be running when the control device  10  is being shifted between the engaged and disengaged positions. 
   Although the invention is disclosed with reference to a particular embodiment thereof, it will become apparent to those skilled in the art that numerous modifications and variations can be made which will fall within the scope and spirit of the invention as defined by the attached claims.