Abstract:
An apparatus is disclosed for removing exceeding portions of laths use to separate pieces of lumber in a bundle. The apparatus comprises an external cage and an internal cage having a skeleton framework mounted to the external cage and displaceable between a retracted position and an extended position in which the internal cage projects forwardly from a front open face of the external cage. A chain-like member carrying a plurality of paddles is provided at a front face of the skeleton framework and is driven by a motor for causing the paddles to strike and break the exceeding portions of the laths.

Description:
TECHNICAL FIELD 
     The invention relates generally to an apparatus for breaking laths and, more particularly, to an apparatus suited for removing the exceeding portions of laths in a bundle or stack of lumber pieces. 
     BACKGROUND OF THE ART 
     It is well known to use wood or lumber separator, commonly referred to as “lath”, “sticker” “crosser”, to separate pieces of lumber in a bundle or stack and allow air to flow between layers of lumber and moisture to escape from the wood. 
     Side-by-side laths or separators typically extend transversely to the length of the pieces of lumbers in the stack. An individual stack is often built up to a height of about 5 feet with the pieces of lumber laid in a spaced and parallel relationship in courses, course upon course, with separators laid between at least some of the courses across the pieces of lumber. The laths often extend beyond one peripheral side of the bundle, thereby interfering with the subsequent wrapping or bagging of the bundle. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of this invention to provide an apparatus for removing the exceeding portions of the laths and, thus, facilitate subsequent processing of the bundles. 
     In one aspect, the present invention provides an apparatus for removing an exceeding portion of a lath used to separate pieces of lumber in a bundle, the exceeding portion extending beyond the periphery of the bundle, the apparatus comprising: an external cage, the external cage having a front open face, and an internal cage having a skeleton framework mounted to the external cage and displaceable between a retracted position and an extended position in which the internal cage projects forwardly from said front open face of said external cage, an upstanding chain-like member carried at a front face of the skeleton framework, a motor for driving the chain-like member, and a plurality of lath breaking paddles mounted to the chain-like member. The chain like-member can include one or more chains. Alternatively, it could be provided as a belt or the like. The chain-like member could also take other forms suited for carrying the paddles along a loop. 
     In a second aspect, the present invention provides an apparatus for removing an exceeding portion of a lath used to separate pieces of lumber in a bundle, the exceeding portion extending beyond the periphery of the bundle, the apparatus comprising: a plurality of lath breaking paddles rigidly mounted to at least one rotary member journaled to a reciprocating structure mounted to a frame for movement toward and away from the bundle, and a motor for driving the rotary member. The term “rotary member” is herein intended to encompass any revolving part to which the paddles could be mounted. It could, for instance, take the form of a wheel, a chain, a belt, or a combination thereof. This is not intended to be a complete list of the possible alternatives. Also various ways are contemplated to reciprocate the rotary member. The structure supporting the rotary member could, for instance, be displaced by a pneumatic or hydraulic piston and cylinder arrangement. Other types of actuators could be used as well. 
     In a third aspect, the present invention provides a method for removing an exceeding portion of a lath used to separate pieces of lumber in a bundle, the exceeding portion extending beyond the periphery of the bundle, the method comprising: advancing the bundle to a lath breaking station and striking the exceeding portion of the lath with a striking tool at said lath breaking station with sufficient force to break the exceeding portion away from the remaining portion of the lath. The striking tool can take various forms as long as it is adapted to strike the exceeding portion of the lath and break it away. For instance, it can take the form of a paddle, a hammer, a bat or any other implements that can be used to hit and break the exceeding portion of the lath. 
     Further details of these and other aspects of the present invention will be apparent from the detailed description and figures included below. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       Reference is now made to the accompanying figures depicting aspects of an embodiment of the present invention, in which: 
         FIG. 1  is a perspective view of a lath breaker in accordance with an embodiment of the present invention; 
         FIG. 2  is a side elevation view of the lath breaker shown in the process of breaking the exceeding portions of a rectangular bundle of laths; and 
         FIG. 3  is a perspective view of an internal cage of the lath breaker. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1 and 2  illustrate a lath breaker  10  for breaking the exceeding portions of the laths L used as spacers in a stack or bundle of lumber pieces or the like. 
     The lath breaker  10  generally comprises a main rectangular frame  12  or external cage, and an internal cage  14  mounted to the main frame  12  for linear movement between a retracted position and an extended position ( FIG. 2 ) through the operation of an actuator, such as a pneumatic cylinder  16  (see  FIG. 2 ) extending between the internal cage  14  and the frame  12 . A cover  18  is bolted on top of the main frame  12  to shelter the internal cage  14 . 
     The main frame  12  preferably includes four upstanding corner posts  20  connected to each other by a suitable number of horizontal tubular side members  22 . Each corner post  20  is provided at a lower end thereof with a mounting flange  24  for allowing the frame  12  to be bolted to the floor on one lateral side of a conveyor C ( FIG. 2 ) adapted to carry the successive bundles B having laths L to be trimmed. 
     As shown in  FIG. 3 , the internal cage  14  has a rectangular skeleton framework  26 , which is provided on each side thereof with two upper carriers  28   a  and one lower carrier  28   b  for slidable engagement with corresponding upper and lower rails  30   a  and  30   b  ( FIG. 2 ) mounted to the internal face of the tubular side members  22  provided on the inlet and outlet sides of the main frame  12  and extending between the front and back corner posts  20  thereof. Accordingly, the internal cage  14  can be pulled into the main frame  12  towards the rear end thereof or pushed out of the frame  12  through the front open face thereof by operation of pneumatic cylinder  16 . 
     As shown in  FIG. 1 , inlet and outlet rollers  32   a ,  32   b  are mounted at the front distal end of respective arms  34   a  and  34   b  extending along opposed sides of the internal cage  14 . The arms  34   a  and  34   b  are securely mounted to the internal cage  14  by means of bolts or the like. The arms  34   a  and  34   b  are preferably telescopic in order to provide for adjustment of the length thereof. A suitable locking mechanism  35  is provided to lock the respective telescopic portions of the arms in various relative positions. The rollers  32   a  and  32   b  are mounted for rotation about a vertical axis and disposed for engaging a side portion of the incoming bundle B below the laths L. The role of the rollers  32   a  and  32   b  is to properly position the internal cage  14  relative to the bundle B for the lath breaking operation. When the rollers  32   a  and  32   b  engage the bundle B, the stroke of the pneumatic cylinder  16  is stopped in order to immobilise the internal cage  14  at the right position relative to the bundle to permit the subsequent breaking of the exceeding portions the spacing laths extending laterally outwardly from the side of the bundle facing the lath breaker  10 . 
     As shown in  FIG. 1 , an inlet safety guard  33   a  and an outlet safety guard  33   b  extend along opposed sides of the internal cage  14  to protect the technician operating the lath breaker  10  from being injured by the exceeding lath portions that are being broken away from the bundles B. As shown in  FIG. 2 , a rear safety guard  33   c  is also provided at the back of the internal cage  14 . 
     As shown in  FIG. 3 , the internal cage  14  further comprises a pair of laterally disposed chains  36   a  and  36   b  extending over respective upper and lower sprocket wheels  38   a ,  38   b  and  40   a ,  40   b . The chains  36   a  and  36   b  run into respective vertical guides  39   a ,  39   b  provided on the front face of the skeleton framework  26 . The upper sprocket wheels  38   a ,  38   b  and the lower sprocket wheels  40   a ,  40   b  are respectively keyed to an upper shaft  42  and a lower shaft  44 . The upper shaft  42  is journaled at opposed ends thereof to the skeleton framework via a pair of bearings  46  mounted at the front upper end of the framework  26 . Likewise, the lower shaft  44  is journaled at opposed ends thereof to the framework via a pair of bearings  48  mounted at the front lower end of the skeleton framework  26 . A third sprocket wheel  50  is securely mounted to the lower shaft  44  and is engaged with a transmission chain  52  ( FIG. 2 ) which is, in turn, engaged with a sprocket wheel  54  provided at the output of an electric motor  56 . The motor  56  is mounted to the rear portion of the skeleton framework  26  of the internal cage  14  and is operational for driving the lower shaft  44  and, thus, the side-by-side chains  36   a  and  36   b  in the direction indicated by arrow  58  in  FIG. 2 . As best shown in  FIG. 2 , a toothed wheel  60  is mounted to the skeleton framework  26  outwardly of the loop defined by the transmission chain  52 . The toothed wheel  60  is engaged with the transmission chain  52  to maintain a proper tension therein. The toothed wheel  60  acts as a tensor for the transmission chain  52 . 
     A plurality of lath breaking paddles  62  (ten in the illustrated example) are rigidly mounted to chains  36   a ,  36   b . The paddles  62  are uniformly distributed along the chains  36   a  and  36   b . Each paddle  62  is secured along the rear edge thereof to both chains  36   a  and  36   b . The paddles  62  extend substantially at right angles from the chains  36   a  and  36   b . Each paddle  62  comprises a ½″×½″ striking plate  64  extending from the front end of a metal casing  66 . The striking plate  64  is preferably removable and made of a rigid non-marking material, like white Teflon, in order not to leave any marks on the side of the bundle B. The casing  66  includes a back plate  68 , a base plate  70  extending from the back plate  68  and having opposed lateral side portions folded upwardly at right angles and a top securing strip  72  ( FIG. 1 ) extending inwardly between the upwardly folded portion of the base plate  70  at a front end thereof. The securing strip  72  and the base plate  70  define a front open gap for receiving the striking plate  64 . Bolts or the like extends through the base plate  70 , the striking plate  64  and the securing strip  72  to provide a rigid paddle assembly. 
     In operation, the bundle B is conveyed to the lath breaker  10 . The pneumatic cylinder  16  is actuated to displace the internal cage  14  towards the bundle B until the rollers  32   a ,  32   b  engage the side of the bundle B. The motor  56  jointly drives the chains  36   a  and  36   b  in rotation to cause the paddles  62  to strike the exceeding portions of the laths L in a descending direction. The exceeding portions of the laths L are broken away from the remaining portion of the laths L under the force of the paddles. 
     The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without department from the scope of the invention disclosed. Such modifications are intended to fall within the appended claims.