Patent Publication Number: US-8123155-B2

Title: Fence wire stretching device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to fence construction, and in particular relates to a vehicle-mounted device for stretching fence wire, such as electric wire, between fence support structures such as posts. 
     2. Description of the Related Art 
     It is difficult and time-consuming to stretch lengths of fence wire, such as electric wire, between posts or other fence support structures. Typically the wire made of aluminum, steel, stainless steel or other fencing material is in a large, heavy spool. To make the fence, the wire is pulled from the spool which is located in a vehicle, such as in the back of a pickup truck. The wire is attached to an initial post, and then unwound to be long enough to reach the next post, stretched taut, and attached to the next post. Because of the distance between posts and the weight of the intervening wire, it is very difficult for one person to pull the wire taut enough, and generally two people are required. 
     There are known devices for holding the spool of wire in a particular position in or on the vehicle. Generally these devices do not provide a way of providing tension or tautness to the wire. The patent of Popps (U.S. Pat. No. 7,530,522) does provide a way to spool fencing from a vehicle that includes a frame that is configured to be attached to a motor vehicle, a pivotable cradle on the frame, a gripper assembly that is made of a gripper shoe, vertical axle and a gripper frame that rotates about the vertical axle and places the gripper shoe into contact with the spool of wire when manual force is placed on the handle by the operator of the motor vehicle. The rolls of wire are placed on the vertical cradle and wire is threaded between the gripper shoe and a fence guide. This prior device is a large complicated device with many parts that is preferably configured so that a handle of the device is accessible by the operator of a tractor on which the device is mounted. The means of attaching to a vehicle includes use of grip pins and a center mount. 
     It is therefore an object of the invention to provide an easily attachable and detachable portable fence wire stretching device that may be attached by one person to a standard trailer hitch adaptor and that extends behind the vehicle horizontally at the level of the hitch. It is a further object to provide a fence wire stretching device on which a roll of wire may be easily placed, and when sufficient wire has been pulled from the roll, the wire may be pulled taut and held in a taut position. 
     Other objects and advantages will be more fully apparent from the following disclosure and appended claims. 
     SUMMARY OF THE INVENTION 
     The invention herein is a fence wire stretching device having a square shape made up of five leg portions, three of which form three of the sides of the square. The fourth side of the square has a proximal leg portion and a distal leg portion that are pivotally attached together. The distal leg portion swings outward at an angle from the proximal leg portion so that the wire clamp mechanism is in an open position, and may then be pivoted back to be coaxial with the proximal leg so that the wire clamp mechanism is in a closed position. A vehicle attachment means is located at a first corner of the square, and a wire clamp mechanism is located at second corner of the square opposite the vehicle attachment means. A wire spool holding rod extends centrally across the square between a third corner and a fourth corner of the device, and is openably attached to the square so that a spool of fence wire may be slipped over the wire spool holding rod. 
     Other objects and features of the inventions will be more fully apparent from the following disclosure and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective rear view of the fence wire stretching device of the invention in a closed position, mounted on a vehicle. 
         FIG. 2  is a perspective rear view of the fence wire stretching device of  FIG. 1  in an open position, mounted on a vehicle. 
         FIG. 3  is a perspective side view of the fence wire stretching device in the closed position, mounted on a vehicle. 
         FIG. 4  is a perspective front view of the fence wire stretching device in the open position. 
         FIG. 5  is a perspective view of one of the L brackets of the fence wire stretching device attached to a corner of the device. 
         FIG. 6  is a perspective view of the pivotable junction of legs A 1  and A 2  of the fence wire stretching device of the invention. 
         FIG. 7  is an upper plan view of the fence wire stretching device of the invention in a closed position. 
         FIG. 8  is an upper plan view of the fence wire stretching device of the invention in an open position. 
         FIG. 9  is a partial side view of the joined leg portions A 1  and A 2  of the invention. 
         FIG. 10  is a partial side view of the wire spool holding rod of the invention. 
         FIG. 11  is a perspective view of the fence wire stretching device with a spool of wire mounted on it and the wire end held in the wire clamp mechanism of the invention. 
         FIG. 12  is a cross-sectional view of the clamp mechanism of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS THEREOF 
     The invention herein is a fence wire stretching device on which a spool of fence wire, such as electrical wire may be held. The wire is spooled out in as known in the art, and when a sufficient length of wire has been pulled from the spool, the fence wire stretching device is used to clamp the wire and hold it tight as the vehicle is used to pull the wire from a distal place of attachment, such as a fence post. 
     As shown in the figures (e.g.,  FIGS. 1-4  and  7 - 8 ), the fence wire stretching device  10  of the invention is preferably generally in the shape of a square with four sides  12  and four 90-degree corners. The fence wire stretching device is made of five leg portions, which are a first leg divided into smaller leg portions A 1  and A 2  that together are along one of the four sides of the device  10 , and three single piece legs B, C, and D, each of which is along another side of the device to form the square shape. The leg portions form equal length sides of the device  10  when the device  10  is assembled. Leg portions A 1  and A 2  (together the first leg portion of the invention) are pivotally attached together so that the distal leg A 2  may swing outward at an angle from proximal leg A 1  as shown in  FIG. 2  so that the wire clamp mechanism is in an open position, and may then be pivoted back to be coaxial with proximal leg A 1  as shown in  FIG. 1  so that the wire clamp mechanism is in a closed position. Leg portions B, C and D, are respectively referred to as the second, third, and fourth leg portions, with the four leg portions together forming a square as discussed and shown herein. 
     At a first corner V proximal to a vehicle  14  to which the device  10  is attached is a vehicle attachment means  16  for attaching to the vehicle  14 , preferably for attaching to a receiver hitch or trailer hitch or similar device as known in the art, and having the same structure for attaching to a vehicle as known in the art. At the corner Y most distal from the vehicle is a wire clamp mechanism  18 . Between the two remaining corners X, Z of the device, a wire spool holding rod  20  extends. 
     The term “perpendicular 45 degree angle” as used herein means that the 45 degree angle cuts on the two ends of a piece of square tubing are perpendicular to each other as shown for example on legs B-D, while a parallel 45 degree angle cut means that the 45 degree angle cut on the two ends of a piece of square tubing are parallel to each other as shown for example on piece A 2 . 
     As shown in  FIGS. 1-4  and  7 - 8 , to make the device  10  of the invention, all of the leg portions (A 1 , A 2 , B, C, D) are preferably made of 1 inch square tubing, such as tubing made of steel as known in the art. Leg B is preferably cut about 20 inches long, and legs C and D are preferably 18¾ inches long when leg B is 20 inches long. Legs B-D have a perpendicular 45 degree angle cut  22  on each end of each leg piece as shown in  FIG. 8 . 
     Two shorter pieces  24  (6¼ inches long) of square tubing are cut, and perpendicular 45 degree angles are cut on both ends leaving a 6¼ inch side. 
     Leg A 1  is formed to be 9½ inches long and is cut at a 45 degree angle at one end and a 90 degree angle on the other end as shown in  FIG. 7 . Leg A 2  is 8½ inches long with parallel 45 degree angles on the ends. 
     Legs D and C are tack welded together and to the chosen attachment means  16 , preferably a 2½ inch receiver hitch adapter as known in the art. Leg A 1  is tack welded to leg D and legs B and C are tack welded together in the position shown so that each corner between a pair of leg portions is at a 90 degree angle ( FIGS. 7-8 ). Two shorter pieces of square tubing (6¾ inches long) are tack welded across the right angles formed by A 1 -D and B-C as shown in  FIG. 5  to form a brace  24  at opposite corners X, Y of the device  10 . 
     Two 4 inch pieces  26  of ¼ inch×1 inch flat steel are tack welded to the unattached end of leg A 1  and parallel to each other, leaving a 3 inch extension  27  of the 4-inch pieces  26  extending beyond the end of leg A 1  by welding 1 inch of each 4-inch piece  26  to leg A 1  ( FIGS. 6 and 9 ). A ⅜ inch diameter hole  28  is drilled through each 4 inch piece  26  at 1⅝ inch from the end of the 4 inch piece that is attached to leg A 1  at ½ inch from the edge of the extension. 
     Two 4¾ inch metal strips  30 A,B are cut from ¼ inch×1 inch flat steel. A ⅜ inch diameter hole  32  is drilled through one of the 4¾ inch pieces ¼ inch from one end (the smooth hole), and a ⅜ inch hole  34  is tapped/threaded ¼ inch from an end of the other 4¾ inch piece. The 4¾ inch piece with the smooth hole  30 A is welded to leg A 2  at the 45 degree angle face and the tapped 4¾ inch piece  30 B is welded to leg B at the unattached 45 degree angle face. These two metal strips together with bolt  56  form the wire clamp mechanism  18 . 
     All tack welds are then final welded. 
     Using two ⅜ inch×5 inch L brackets  36  ( FIGS. 5 and 10 ), a ½ inch hole  38  is cut through the short arm  40  of each “L” bracket, ¾ inch from end. The long arm  42  of each L bracket  36  is welded to one of the opposite corners X, Y of the device  10 , with the long arm  42  being welded both to the intersecting legs of the device and the brace  24  at that corner of the device. 
     A flat piece  44  of 4 inch×8 inch flat steel is welded to the bottom of the receiver hitch (attachment means  16 ) and to the attached portions of legs D and C to strengthen the device  10  at its point of attachment to a vehicle. Flat piece  44  is shown as rectangular; however, it may be made in any shape so long as it provides added strength to the attachment area of the device  10 . 
     To form the wire spool holding rod  10 , a 21-inch long piece of ½ inch round stock (e.g., steel, stainless steel or the like) is mushroomed at one end  46  as known in the art. On the opposite end  48  of the mushroom end  46  of the round stock, holes  50  are drilled at intervals, for example, at 5¾ inch, 6¾ inch, 7¾ inch, 12¾ inch, 13¾ inch and 14¾ inch from the opposite end  48 , as well as at ¾ inch from opposite end  48 . The wire spool holding rod  10  is pulled through the hole  38  in one of the L brackets  36 , and two 2-inch washers  52  with a ½ inch center hole are slipped on to the wire spool holding rod  10 . The free end  48  of the wire spool holding rod  10  is placed through hole  38  in the other L bracket  36 . One 1½ inch cotter pin  54  is placed in the wire spool holding rod  10  in the ¾ inch distance hole on the end of the wire spool holding rod  10 . Two other 1½ inch cotter pins  54  are placed in the desired location on the wire spool holding rod  10  to fit the wire spool size so that a cotter pin  54  is on each side of the wire spool as shown in  FIG. 11  with the washers  52  on the wire spool holding rod  10  between the cotter pins  54  and the wire spool  60 . 
     A hole  29  is drilled in leg A 2  at ½ inch from the end of leg A 2 . Leg A 2  is placed between the extensions  27  on leg A 1  and the holes  28 , 29  are lined up. A half-threaded bolt  58  (¼ inch by 2¾ inch) is inserted through the lined up holes  27 , 28  and two corresponding sized nuts are threaded on the 2¾ inch bolts. The two nuts on each bolt are tightened in opposite directions as known in the art. 
     To finish assembly of the device, the entire device  10  is preferably painted with primer paint, and when dry is painted black. On leg A 2 , a section  62  that extends between 3¾ inches and 6¼ inches from hole  27  is painted red as an indication means to show where inside the device  10  to drive a standard T-post as known in the art. Preferably, to assist in centering the wire spool on the device, a ½ inch red stripe is painted on the round stock at 7¾ inch and 12¾ inch from the end the wire spool holding rod  10 , a ½ inch yellow stripe is painted at 6¾ inch and 13¾ inch from the end the wire spool holding rod  10 , and a ½ inch green strip is painted at 5¾ inch and 14¾ inch from the end the wire spool holding rod  10 . 
     To use the device of the invention, the assembled device  10  is attached to a trailer receiver hitch on a truck or other vehicle. At or before reaching the fencing site, a spool  60  of wire is placed on the device  10  ( FIG. 11 ) by pulling the wire spool holding rod  20  sufficiently outward from the L brackets so that end  48  is free of the L bracket and the wire spool  60  can be placed over the free end  48  of the wire spool holding rod holding rod  20  and centered between a pair of cotter pins  54  placed in holes  50 , with a washer  55  on each side of the spool  60  between the cotter pin  54  and the spool  60 . The wire spool holding rod  20  is again fixed in the L bracket  36  by placing a cotter pin in a hole nearest end  48 . 
     Wire is pulled off the spool  60  by hand at the first T-post and attached to the first T-post insulator as known in the art. The vehicle is driven down the desired fence line and stopped at the desired position of the second T-post. The wire is placed between pieces  30 A and  30 B and the bolt is tightened The vehicle is pulled forward slowly until the desired tautness of the wire is reached. The second T-post is driven inside the device adjacent to leg A 2 . Wire is pulled from the spool to provide sufficient wire for attaching to the post, and wire is cut by hand and wrapped around the insulator as known in the art. The wire clamp mechanism  18  is opened to release the wire, being careful not to be clear of the wire as it is released from the wire clamp mechanism  18 . The vehicle can then be pulled forward so that the opened device is pulled past and beyond the second T-post. Additional lengths of wire along the desired fence line are spooled and attached to posts in the same manner by repeating the above steps 
     While the invention has been described with reference to specific embodiments, it will be appreciated that numerous variations, modifications, and embodiments are possible, and accordingly, all such variations, modifications, and embodiments are to be regarded as being within the spirit and scope of the invention.