Abstract:
A material distribution system for stick-like objects such as railroad spikes includes a rake for peeling the stick-like objects from the top of a pile, and transferring them to another location, for example, where they might be reached by a human operator. Use of the rake to peel the object from the top of the pile, with minimized downward pressure applied by the rake, minimizes the tendency of the objects to entangle with each other.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to material handling systems for stick-like articles, for example, railroad spikes. More specifically, the invention is a rake for moving railroad spikes from a storage location to a workstation. 
     2. Description of the Related Art 
     Railroad spikers used for assembly or repairing sections of railroad tracks typically utilize a wide variety of automatic and manual means for loading spikes into the spiker. Both automatic and manual loading methods require transport of the railroad spikes from a storage location to a location wherein they can be loaded into the spiker without causing entanglement of the spikes, and automatic spikers further require means for properly orienting the spikes and loading the properly oriented spike into the spiker. 
     An example of a proposed railroad spike material handling system includes a centerless auger rotating approximately 360° in the desired direction of travel for the spikes, and then backwards 45° in an attempt to untangle any tangled spikes. A vibrating storage bin may be used to feed spikes into the auger mechanism. 
     Another material handling system includes a horizontal conveyor leading from a spike hopper to a vertical conveyor having a plurality of projecting fingers for receiving the spikes and transporting them towards the upper portion of the spike feeder. As the spike is dropped into the spike feeder, it will strike a ridge, causing the spike to be aligned either perpendicular to the spike&#39;s direction of travel, or with the spike point facing the direction of travel. Camming walls then ensure that all spikes are oriented with the point facing the direction of travel. Once the spike is so oriented, it falls into the spike-driving assembly. 
     Spike material handling systems designed to vibrate, stir, tumble, or auger the spikes to the desired location typically have varying degrees of success, due to the tendency of the spikes to entangle with each other. 
     Yet another presently used spike distribution system includes a powered winch for lifting containers of spikes, and emptying them in a location wherein an operator may reach the spikes and load them into a spike driver. 
     Accordingly, a spike distribution system preventing entanglement of the spikes during transportation is desired. Additionally, a spike distribution system having greater efficiency, and not producing excessive noise, is also desired. 
     SUMMARY OF THE INVENTION 
     The present invention is a spike distribution system for delivering spikes from a storage location to a location wherein they may be reached by an operator for loading into a spiker. The spike distribution system includes a spike rake for moving the spikes from the storage location to the operator&#39;s location. 
     The spike rake includes a horizontally oriented rake head having a plurality of prongs on either end of the head. The prongs are dimensioned and configured to engage a spike either along its length or at the spike head. The rake is pivotally secured to an arm that may be raised or lowered to engage the spikes at the top of the storage location. An example of means for raising and lowering the arm include a hydraulic cylinder secured between the end of the arm and the shaft. The pivotal attachment of the rake permits the rake to remain horizontal due to the effects of gravity as the rake is raised and lowered and to permit the rake to pivot to correspond to the top of a pile of spikes. The arm is secured to a substantially vertical shaft that may be rotated to change the position of the rake, with an example of means for rotating the shaft being a hydraulic cylinder secured to another arm extending a short distance from the shaft. 
     Spikes will typically be stored in bulk behind the operator of the spike driver. The operator&#39;s workstation will typically include at least one location adjacent to the operator&#39;s seat wherein a small number of spikes may be stored within reach of the operator. A spike rake assembly will be located behind and to one side of the operator, wherein it may be used to move spikes from the storage location to the operator&#39;s work station. When additional spikes are needed at the operator&#39;s work station, the shaft may be rotated to locate the spike rake above the pile of spikes. The rake will pivot to maximize the number of prongs in contact with the spikes. The arm is then lowered to bring the spike rake into contact with the top of the pile of spikes. The shaft is then rotated to move the spike rake towards the operator&#39;s workstation while maintaining a small amount of downward pressure on the spike rake, thereby enabling the spike rake to peel some spikes from the top of the pile of spikes without causing entanglement of the spikes. Once the spike rake has reached the storage location at the operator&#39;s work station, the arm may be raised, and the spike rake again rotated towards the storage location in preparation to transfer the next set of spikes. The operator may then reach the storage location at his workstation, grab a spike, and load it into the spike driver for driving through a tie plate and railroad tie. 
     A preferred workstation for a spiker operator will include two small storage areas for spikes within reach of the operator, with one storage area on each side of the operator. One spike rake will be positioned to transfer spikes into each storage area, so that the operator will control a total of two spike rakes. 
     It is therefore an aspect of the present invention to provide a spike distribution system preventing entanglement of the spikes. 
     It is another aspect of the present invention to provide a spike distribution system having a high efficiency. 
     It is a further aspect of the present invention to provide a spike distribution system avoiding generation of excess noise. 
     It is another aspect of the present invention to provide a spike rake for peeling spikes from the top of a spike pile, and transferring them to a location wherein a spiker operator may reach them. 
     These and other aspects of the invention will become apparent through the following description and drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front isometric view of a spike distribution system according to the present invention. 
     FIG. 2 is an isometric view of a spike rake assembly for a spike distribution system according to the present invention. 
     FIG. 3 is a top view of a spike distribution system according to the present invention. 
    
    
     Like reference numbers denote like elements throughout the drawings. 
     DETAILED DESCRIPTION 
     The present invention is a material distribution system for elongated objects. The material distribution system transfers the elongated objects from a storage location, located behind an operator&#39;s seat, to a destination location, wherein the elongated objects may be reached by the operator. Although not limited to such use, the material handling system of the present invention is particularly useful for transferring railroad spikes from a storage location to a location wherein they may be reached by the operator of a spike driver, and the invention will be described herein based on this example embodiment. 
     Referring to FIG. 1, a typical workstation for the operator of a spike driving apparatus is illustrated. The workstation  10  includes an operator&#39;s chair  12 , located in a position enabling the human operator to easily reach the spike driving apparatus (not shown, and well known in the art) for loading spikes into the apparatus. A bulk storage bin  14  for the spikes is located behind the operator&#39;s chair  12 . The bulk storage bin  14  includes a floor  16 , front wall  18 , rear wall  20 , and angled side walls  22 . The workstation  10  also includes at least one, and more preferably two, small operator-accessible storage bins  24 , located within easy reach of the operator&#39;s chair  12 . The illustrated example includes two small storage bins  24 , with one bin  24  on either side of the operator&#39;s chair  12 . Each bin  24  includes a floor  26 , at approximately the same height or slightly lower than the floor  16  of the bulk storage bin  14 . The small storage bins  24  also include front walls  28 , and side walls  30 . A passageway  32  is defined between the ends  34  of the spike bin&#39;s front wall  18 , and the ends  36  of the bulk spike bin&#39;s side walls  22 . The bulk spike bin  14  is therefore in communication with the small storage bins  24 , permitting passage of spikes from the bulk spike  14  to the smaller storage bins  24 . The workstation  10  also includes at least one spike rake assembly  38  for each small storage bin  24 , with a preferred total number of spike rakes  38  at a workstation  10  being two. 
     The spike rake assembly  38  is best illustrated in FIG.  2 . The spike rake assembly  38  includes a shaft  40 , rotatably mounted on the workstation  10 . The shaft  40  has a lower portion  42  including an arm  44  connected between the shaft  40  and the means for rotating the shaft. The illustrated example includes a hydraulic cylinder  46  pivotally secured to the arm  44  for rotating the shaft  40 . Extending the hydraulic cylinder  46  thereby rotates the shaft  40  in one direction, and retracting the hydraulic cylinder  46  rotates the shaft  40  in the opposite direction. 
     The top end portion  48  of the shaft  40  includes a boom assembly  50 . The boom assembly  50  includes a boom  52 , pivotally secured at the top portion  48  of the shaft  40 , so that it may pivot within a vertical plane. The outer end  54  of the boom  52  preferably includes a downwardly extending arm  56 . The boom assembly  50  also includes a hydraulic cylinder  58 , extending between the top portion  48  of the shaft  40 , and the outward end  54  of the boom  52 . The hydraulic cylinder  58  is pivotally secured at each of these locations. Extending the hydraulic cylinder of the illustrated example lowers the boom  52 , and retracting the hydraulic cylinder  58  raises the boom  52 . 
     A spike rake is pivotally secured to the outer end  54  of the boom  52 , preferably at the end of the arm  56  by the pivot  70 . The spike rake  60  includes a base portion  62  and at least one set  64  of prongs  66 . The illustrated example includes a horizontal, substantially planar base portion  62 , having a pair of prong sets  64 , with one prong set  64  located adjacent to the front of the base  62 , an the other prong set  64  located adjacent to the rear of the base  62 . The prongs  66  are dimensioned and configured to permit passage of the body portion of a railroad spike, but not the head portion of the railroad spike between them. The prongs  66  are preferably pointed approximately in the spike rake&#39;s direction of travel along the arcuate path between the bulk storage bin  16  and small storage bin  24  and angled downward. The pivot  70  permits the rake  60  to pivot about an axis that is substantially horizontal and substantially parallel to its direction of travel along its arced path from the bulk storage bin  14  to the operator-accessible bin  24 . 
     Operation of the spike rake assembly  38  is best illustrated in FIGS.  3 . The spike rake assembly is controlled by the joystick  68 . When the human operator seated in the chair  12  wishes to move additional spikes from the bulk storage bin  14  to either of the smaller storage bins  24 , the operator uses the joystick  68  to retract the hydraulic cylinder  46 , thereby rotating the shaft  40  to bring the spike rake  60  to a first position (shown by rake assembly  38   a  in FIG.  3 ), corresponding to one end of its range of travel. The operator next uses the joystick  68  to extend the hydraulic cylinder  58 , thereby lowering the spike rake  60  on top of the pile of spikes within the bin  14 , and applying a small amount of downward pressure to the rake  62 . The operator may control the degree of downward pressure by the extent to which he moves the joystick  68 , thereby providing only the desired amount of downward pressure. While maintaining this downward pressure, the operator again manipulates the joystick  68  to extend the hydraulic cylinder  46 , thereby moving the spike rake  60  from a first position above the pile of spikes in the bulk spike bin  14  to a second position above the smaller storage bin  24 . 
     As the spike rake  60  moves from the first position to the second position (shown by rake  38   b  in FIG.  3 ), railroad spikes are peeled off the top of the pile by the prongs  66 , catching between and in front of the prongs  66 , and thereby being pushed along with the spike rake  60  towards the small storage bin  24 . During this movement, the operator may choose to further extend the hydraulic cylinder  58 , lowering the spike rake  60  to maintain contact with the railroad spikes as lower portions of the spike pile are encountered. Additionally, the spike rake  60  may pivot around the pivot  70  to maximize the number of prongs  66  in contact with the spikes if the spike rake  60  contacts the pile of spikes at a position wherein the spike pile is not horizontal. Once the second position has been reached, the operator may again manipulate the joystick  68  to retract the hydraulic cylinder  58 , thereby raising the spike rake  60 , and to retract the hydraulic cylinder  46 , thereby moving the spike rake  60  to a position wherein it will be out of the way of his reaching the spikes within the small storage bin  24 , and loading them into the spike driving apparatus. 
     While a specific embodiment of the invention has been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of the invention which is to be given the full breadth of the appended claims and any and all equivalents thereof.