Abstract:
Locking apparatus adapted for releasably holding a first member, which can be, for instance, a relatively heavy member or device such as a crop residue spreader, in one or more predetermined positions relative to a second member, which can be, for instance, a fixed structure of an agricultural combine, which apparatus when locked and actuated or moved into an unlocking mode will automatically unlock when any forces urging the apparatus to remain in the locked condition are overcome or removed or are otherwise absent, and which when actuated or moved into a locking mode, will automatically lock the members together when in or moved to one of the predetermined positions.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates generally to a locking apparatus, and more particularly, to a locking apparatus adapted for releasably locking relatively movable members in at least one predetermined relative position, which apparatus is operable in an unlock or release mode to automatically unlock and release the members when any force opposing the release is removed or otherwise absent, and which is operable in a locking mode for automatically locking the members together when moved to one of the predetermined relative positions.  
       BACKGROUND ART  
       [0002]     Locking apparatus operable for releasably locking together two relatively movable members are well known. Such apparatus can generally be divided into two categories, those providing an automatic unlocking capability in the unlocking mode, and those that provide an automatic locking capability when in a locking mode. Reference as an example in this first regard, Hogan U.S. Pat. No. 4,217,064, issued Aug. 12, 1980, to Spectrum X-Ray Corporation, which discloses a latching mechanism incorporating a pivotal cam operable in a locking position for driving a spring loaded plunger into a receiver for holding two members together. In this mechanism, the spring urges the plunger from the receiver when the cam is moved to an unlock position, to allow the members to be relatively moved. However, the spring loaded plunger must be aligned with the receiver for the cam to be moved to the locking position. Thus, no automatic locking capability is provided.  
         [0003]     Reference in the second regard, Jermyn, Jr. U.S. Pat. No. 6,065,896, issued May 23, 2000 to the United States of America, which discloses a lever device having an automatic locking capability when in a locking mode. However, no mechanism is provided for automatically unlocking the device when in an unlock mode.  
         [0004]     Here, what is meant by an automatic unlocking capability in an unlocking mode is for the locking apparatus to automatically release or disengage the relatively movable members to allow the relative movement thereof, when or after the apparatus is actuated or moved to an unlocking mode, such as by actuation or movement of an actuating element such as a lever, latch, or the like. What is meant by an automatic locking capability when in a locking mode is to lock the members together when in a selected predetermined relative position when or after the apparatus is actuated or moved to a locking mode by actuation or movement of the actuating element.  
         [0005]     There are numerous applications in which it would be advantageous to have a locking apparatus which provides both an automatic locking capability when actuated or moved to an unlocking mode, and an automatic locking capability when moved to a locking mode. As an example, a crop residue spreader is often supported on a rear end of an agricultural combine for movement between one or more operating positions, and a service or access position. Such spreaders are typically relatively heavy devices and require locking apparatus on two sides thereof to be releasably supported in a selected position. Reference in this regard, Wolters et al. U.S. Application Publication No. U.S. 2003/0114207A1, published Jun. 19, 2003, which discloses a multi-position linkage and locking mechanism adapted for such application. This mechanism utilizes spring loaded pins receivable in holes at different locations on a supporting structure when the spreader is moved to one or more predetermined positions, for releasably holding the spreader in the position. To release the spreader, a release bar is moved to a release position to pull the pins from the holes in opposition to the springs. However, in some positions, a substantial portion of the weight of the spreader can be acting to hold the pins in the holes, such that to release the spreader, both the spring forces acting to hold the pins in the holes and the portion of the weight of the spreader acting on the pins must be simultaneously overcome.  
         [0006]     Thus, what is sought is a locking apparatus adapted for releasably holding a relatively heavy device such as a crop residue spreader or the like, which is actuatable or movable into an unlocking mode so as to automatically unlock when any forces urging the apparatus to remain in the locked condition are overcome or removed, and when actuated or moved into a locking mode, will automatically lock when the heavy device is moved in a predetermined manner and/or to a predetermined position.  
       SUMMARY OF THE INVENTION  
       [0007]     What is disclosed is locking apparatus adapted for releasably holding a first member, which can be, for instance, a relatively heavy member or device such as a crop residue spreader, in one or more predetermined positions relative to a second member, which can be, for instance, a fixed structure of an agricultural combine, which apparatus when locked and actuated or moved into an unlocking mode will automatically unlock when any forces urging the apparatus to remain in the locked condition are overcome or removed or are otherwise absent, and which when actuated or moved into a locking mode, will automatically lock the members together when in or moved to one of the predetermined positions.  
         [0008]     According to a preferred aspect of the invention, the apparatus includes a locking element which is preferably a pin supported on the first member for movement along a predetermined path in a first direction toward the second member to a locking position wherein an end of the locking element or pin will be cooperatively received in a receptacle on the second member when the members are in the at least one predetermined position. The pin is also movable in an opposite second direction away from the second member to an unlocking position wherein the end of the pin will be removed from the receptacle. The apparatus includes an actuating element which is preferably a lever supported on the first member for movement in a direction in opposition to a first resilient biasing element to a release position for applying a resilient biasing force in the second direction against the pin for automatically removing the pin from the receptacle when the biasing force exceeds any opposing force acting to hold the pin in the receptacle, the actuating element or lever being movable in an opposite direction in cooperation with or against the pin to move the pin in the first direction to the locking position. The apparatus includes a second resilient biasing element on the first member disposed for urging the lever in the opposite direction, and a latch supported on the first member for movement between a latching position in engagement with the lever when in the release position for releasably holding the lever in the release position, and an unlatched position disengaged from the lever to allow the second resilient biasing member to automatically move the lever in the opposite direction to move the pin in the first direction including to the locking position when the members are in one of the predetermined relative positions. The biasing elements are preferably each a spring.  
         [0009]     According to another preferred aspect of the invention, the first member is movable along a predetermined path relative to the second member, and the second member includes an element which is preferably a cam cooperatively engageable with the latch when in the latching position and the first member is moved to a predetermined position along the path, for moving the latch to the unlatched position such that the lever will be free to be moved by the second resilient biasing element so as to automatically move the end of the pin into the receptacle when the members are moved to one of the predetermined positions. The first member can be movable along the path between two of the predetermined relative positions, and the element on the second member can be disposed between the two predetermined relative positions so as to be engageable with the latch when the first member is moved between the two predetermined positions.  
         [0010]     As a result, in operation, when the first and second relatively movable members are locked together by the locking apparatus and a force, which can be, for instance, a substantial portion or all of the weight of one of the members and anything supported thereby, is acting to hold the pin in the receptacle, when the lever is moved to the release position, the resilient biasing force of the first resilient biasing element will act to remove the pin from the receptacle when the opposing force is overcome, removed, or sufficiently diminished. The lever can be maintained in the release position by the latch to effect the unlocking, and then the latch automatically moved to the unlatched position by relative movement of the members in a predetermined manner or along a predetermined path, as desired or required for a particular application. If no opposing force is present when the lever is moved to the release position the pin will be instantaneously removed.  
         [0011]     As a preferred element for effecting unlatching of the latch by the relative movement of two members, a cam can be provided on second member at a predetermined location along a path of the relative movement, for cooperatively engaging and moving the latch to the unlatching position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a side view of an agricultural combine including locking apparatus for releasably holding a movable crop residue spreader and a first member of the combine in predetermined positions relative to a fixed second member of the combine according to the present invention;  
         [0013]      FIG. 2  is an enlarged fragmentary side view of the combine of  FIG. 1 , showing the locking apparatus and the spreader supported on the first member mounted on the combine for pivotal movement relative to the second member, the locking apparatus releasably holding the first member in a first predetermined position relative to the second member;  
         [0014]      FIG. 3  is an enlarged fragmentary side view of the combine of  FIG. 1 , showing the locking apparatus and the spreader supported on the first member in a second predetermined position relative to the second member;  
         [0015]      FIG. 4  is an enlarged fragmentary front view of the locking apparatus of  FIG. 1  in a locking mode with a locking element of the apparatus releasably received in a receptacle on the second member;  
         [0016]      FIG. 5  is another enlarged fragmentary front view of the apparatus of  FIG. 1  in an unlocking mode wherein the locking element is withdrawn from the receptacle on the second member to allow pivotal movement of the first member relative thereto;  
         [0017]      FIG. 6  is an exploded view of the apparatus of  FIG. 1 , showing the order of installation thereof on the first member and pivotal mounting of the first member relative to the second member;  
         [0018]      FIG. 7  is a simplified fragmentary schematic representation showing a cam on the second member for moving the locking apparatus to the unlocking mode; and  
         [0019]      FIG. 8  is another simplified fragmentary representation of the locking apparatus, showing a latch thereof engaged with the cam for releasing the locking element of the apparatus. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]     Referring now to the drawings, in  FIGS. 1, 2  and  3 , a representative agricultural combine  10  is shown, having a rear end  12  supporting a crop residue spreader  14  for pivotal movement between several predetermined positions, including, but not limited to, at least one operational crop residue spreading position ( FIGS. 1 and 2 ) and a raised position ( FIG. 3 ) for allowing access to internal components of combine  10  within rear end  12 . Spreader  14  is supported by a pair of elongate frame members  16  (one shown) located on opposite sides thereof and mounted for pivotal movement on rear end  12  by a pair of pivot joints  18 , in the directions denoted by arrows A in  FIGS. 2 and 3 . Frame members  16  are each preferably of sheet metal or other rigid construction, and are releasably lockable in a selected one of the predetermined positions by a locking apparatus  20  constructed and operable according to the teachings of the present invention, for holding spreader  14  in the selected position.  
         [0021]     Referring also to  FIGS. 4, 5  and  6 , each locking apparatus  20  includes a locking element  22  which is preferably an elongate pin of steel or other rigid hard material and of rectangular cross-section. Locking element  22  is supported by a base  24 , which is preferably a plate or sheet of steel or other metal, on one side of frame member  16 , and a bracket  26 , which is preferably of sheet metal construction, on the opposite side, for movement along a predetermined path in a first direction, denoted by arrows B in  FIGS. 4 and 5 , toward a second member  28 , which can also be of plate or sheet metal construction and which is fixedly mounted on rear end  12 , and in an opposite second direction, as denoted by arrows C in  FIGS. 4 and 5 . Second member  28  includes holes or receptacles  30  therein at spaced locations corresponding to the predetermined positions of spreader  14  and frame member  16 , for cooperatively receiving an end  32  of locking element  22  when in a locking position ( FIG. 4 ) for holding spreader  14  and frame member  16  at the predetermined positions, respectively. Locking member  22  is movable in the second direction C away from second member  28  to an unlocking position ( FIG. 5 ) wherein end  32  is removed from receptacle  30 , to allow free movement of spreader  14  and frame member  16  relative to second member  28 . Base  24  and bracket  26  can be held together on frame member  16  in any suitable manner, for instance, by an array of bolts  34  which pass through holes in base  24 , frame member  16  and bracket  26 , and secured with nuts  36 .  
         [0022]     Apparatus  20  includes an actuating element  38 , which is preferably a lever, supported on frame member  16  by base  24  and bracket  26 , for pivotal movement from a position shown in  FIG. 4 , in a direction denoted by arrow D, in opposition to a first resilient biasing element  40  to a release position ( FIG. 5 ) for applying a resilient biasing force, denoted by arrow F 1 , in the second direction against locking element  22  for automatically removing locking element  22  from receptacle  30  when the biasing force F 1  exceeds any opposing force acting to hold locking element  22  in receptacle  30 . Such opposing force can result from, for instance, locking element  22  bearing a portion of the weight of spreader  14  and frame member  16  such as when spreader  14  is supported in a position such as shown in  FIG. 3 , and/or friction resulting from contact between, and rust, dirt and/or corrosion on, the surfaces of receptacle  30  and locking element  22 . First resilient biasing element  40  is preferably a spring located around locking element  22  and retained in position by spring retainers  42 . The outer spring retainer  42  is held on element  22  by a pin  44  which is frictionally retained in a hole through element  22 , and the other retainer  42  is held in position by a second pin  44  through another hole in element  22  located adjacent to an opposite surface of actuating element  38 . Actuating element  38  is also movable in an opposite direction, denoted by arrow E in  FIG. 5 , in cooperation with locking element  22 , in particular, against and through second pin  44 , to move locking element  22  in the first direction B to the locking position. A second resilient biasing element  46 , which is also preferably a spring, is disposed in connection between actuating element  38  and a latch  48  mounted for pivotal movement on frame member  16 , for urging actuating element  38  in opposite direction E against second pin  44  and locking element  22 .  
         [0023]     Latch  48  is supported on frame member  16  by a pivot pin  50  which extends through bracket  26  and latch  48 , for pivotal movement, denoted by arrows G in FIGS.  4  and  5 , between a latching position ( FIG. 5 ) in engagement with actuating element  38  when in the release position, for releasably holding actuating element  38  in that position, and an unlatched position ( FIG. 4 ) disengaged from actuating element  38  to allow second resilient biasing member  46  to exert a biasing force F 2  ( FIG. 5 ) against actuating element  38  to automatically move actuating element  38  in opposite direction E to move the locking element in the first direction B including to the locking position when frame member  16  is in one of the predetermined positions relative to member  28 , such as illustrated by the positions shown in  FIGS. 2 and 3 .  
         [0024]     Latch  48  and actuating element  38  include suitable elements for holding actuating element  38  in the latching position. Here, latch  48  extends through a hole in actuating element  38  bordered at one end by an edge  52 , and includes a notch  54  cooperatively engageable with edge  52 , for releasably holding element  38  as shown in  FIG. 5 . Because second biasing element  46  is connected between actuating element  38  and latch  48 , biasing element  46  acts to urge actuating element  38  in direction E and latch  48  in the clockwise direction, which serves to hold edge  52  in notch  54 . To release or unlatch actuating element  38 , latch  48  is pivoted in the counterclockwise direction to disengage notch  54  from edge  52 .  
         [0025]     Referring also to  FIGS. 7 and 8 , second member  28  preferably includes an element  56 , which is preferably a cam or edge, located along a path of movement of frame member  16 , denoted by line H ( FIG. 7 ), at a position so as to cooperatively engage an element  58  on latch  48  ( FIG. 8 ), for pivotally moving latch  48  to disengage edge  52  and notch  54  and move latch  48  from the latched position to the unlatched position, such that actuating element  38  will be urged by second biasing element  46  in direction E. Actuating element  38  will then act to urge locking element  22  in direction B toward second member  28 , and, when frame member  16  is moved along path H such that locking element  22  is positioned for entry into one of the receptacles  30  ( FIG. 5 ), actuating element  38  will drive end  32  of locking element  22  into the receptacle  30  ( FIG. 4 ).  
         [0026]     As a result, in operation, when frame member  16  and member  28  are locked together by locking apparatus  20  and a force, which can be, for instance, a substantial portion or all of the weight of spreader  14 , is acting to hold locking element  22  in receptacle  30 , when actuating element  38  is moved to the release position, the resilient biasing force of first resilient biasing element  40  will act to automatically remove locking element  22  from receptacle  30  when the opposing force is overcome, removed, or sufficiently diminished. If no opposing force is present when actuating element  38  is moved to the release position, locking element  22  will be instantaneously removed from the receptacle to the position shown in  FIG. 5 . Actuating element  38  can be maintained in the release position by latch  48  to enable or facilitate the unlocking, for instance, to allow a person to lift spreader  14  and frame member  16  to remove or lessen the opposing force. Then, latch  48  can be moved to the unlatched position either manually, or by movement of frame member  16  along path H, to effect automatic locking when locking element  22  is positioned for entry into one of the receptacles  30 .  
         [0027]     Here, it should be remembered that in the representative example, a locking apparatus  20  is located on a each side of spreader  14 , and that element  38  of each apparatus  20  must be actuated or moved in the above described manner to its locking and unlocking modes. It should also be noted that in the locked mode shown in  FIG. 4 , locking element  22  can be maintained in receptacle  30  by biasing forces exerted by one or both of biasing elements  40  and  46 , as desired or required for a particular application.  
         [0028]     It will be understood that changes in the details, materials, steps, and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the invention. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.