Patent Publication Number: US-2007098522-A1

Title: Retractable nail device

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates to a retractable nail device, more particularly to an attachment device to any solid, fibrous or cellular materials or the like, including wood, metal, plastic or composite materials, which can be retracted without destroying the material to which the retractable nail device is inserted into.  
      2. Description of the Related Art  
      The wood floor nail  3  of  FIG. 12  and the wood floor staple  13  illustrate prior art attachment devices that are used to attach wood floor boards to the sub floor, in the manner similar to the illustration of  FIG. 11 . The wood floor nail  3  has a main head  30  and a main body  32 , lateral extensions  34  on front and rear sides of the main body  32 , and a tip  35 . The wood floor nails  3  are generally placed in a magazine clip attached to a pneumatically or electrically powered nail gun. The nails  3  are readily inserted into wood floor boards, with the main head  30  anchored to an outer surface of the wood floor board, but the nail  3  can not be easily removed. In the event that one has mistakenly inserted the nail  3 , there is no easy means of removing the nail  3 . Somehow the main head  30  must be grasped and pulled, causing damage to the delicate wood floor board, and the lateral extensions  34  that act to retain the nail  3  into the wood floor board and sub floor will destroy or at least significantly damage the wood floor board, as well as the sub floor when the nail  3  is pulled out. The lateral extensions  34  are not part of any helical screw thread and therefore, rotation of the nail  3  will not form a screw bore/helical thread bore that would permit the escape of the nail  3  out of the wood floor board and sub floor without significant damage to the wood material.  
      The wood floor staple  5  of  FIG. 13  is also used to attach wood floor boards to a sub floor. The staple  5  includes a pair of legs  55  and a connector  52  connected to the legs  55 . The staples  5  are usually placed in a magazine feed attached to a staple gun and the legs  55  are stapled into the wood floor board and sub floor, in a manner similar to the nail  1  shown in  FIG. 11 . The connector  55  rests on the wood floor board at a location similar to the main head  10  of the nail  1  in  FIG. 11 . The problem with the staple  52  is that the connector  52  tends to strongly impact the wood floor board, often shearing off pieces of the wood floor board on impact and thereby destroying the wood floor board. The use of a staple gun is not recommended when using brittle wood material or expensive materials, such as aged wood or the like. The staples  5  are easily dispensed but in addition to the disadvantage mentioned above, the staples  5  can not be readily or easily removed. If the staple  5  is applied incorrectly, the connector  52  must somehow be grasped and pulled to try to remove the staple. This is a highly time-consuming process which may lead to irreparable damage to the wood floor board.  
      Ordinary screws (not shown), such as wood screws, have a helical thread that spirals from at or near the piercing tip towards the head portion along its longitudinal length around a main body or shaft, as in the wood screw of U.S. Pat. No. 4,572,720. Such screws generally have a tool receiving slot for receiving a retracting tool such as a Phillips head screw head, Allen wrench, or the like, and are attached to a material by using a power tool that rotates the retracting tool which has been inserted into the tool receiving slot of the screw head. A helical threaded bore is formed in the material when the screw is inserted via rotation thereof. Such procedure also enables the screw to be retracted (via counter-rotation, leaving behind the helically threaded bore) without any significant damage to the material such as a wood floor, but the insertion by screw rotation of individual screws is highly time-consuming and labor-intensive, which significantly adds to overall building costs, i.e. laying wood flooring.  
      Therefore, there is a need for an attachment device that can be quickly and easily be inserted into wood material or similar materials (i.e. via a nail gun), but which can be removed without significantly damaging or destroying the material.  
     SUMMARY OF THE INVENTION  
      Accordingly, it is an object of the present invention to provide a retractable attachment device which can be easily and quickly attached to wood material or the like, and yet is able to be removed without significantly damaging or destroying the material.  
      Another object of the invention is to provide a retractable attachment device for attaching wood floor boards to the sub floor when laying wood flooring, such device including a breakaway portion that breaks off the device when the device is retracted by rotation along its longitudinal length.  
      Yet another object of the invention is to provide a retractable nail device having a main body having sides formed by front, rear and two lateral sides, with the front and rear sides thereof having rows of partial thread sections, and the lateral sides with missing thread sections, such that after the retractable nail device is nailed into a material, and the nail device can be rotated around the longitudinal axis of the main body, causing a helically threaded bore to be formed as the retractable nail is screwed out of the material, just as a helically threaded wood screw creates such a bore when it is inserted or removed (via rotation) from a block of wood.  
      Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereafter. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art form this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will become more fully understood from the detailed description given below and the accompanying drawings are given by way of illustration only and thus are not limitative of the present invention, and wherein:  
       FIG. 1  is a side view of the retractable nail of the present invention.  
       FIG. 2  is a top plan view of the retractable nail of present invention.  
       FIG. 3  is a cutaway view of the retractable nail of the present invention along line line  3 - 3  of  FIG. 1 .  
       FIG. 4  is a front view of the retractable nail of present invention.  
       FIG. 5  is a rear view of the retractable nail of present invention.  
       FIG. 6  is a side view of an embodiment of the present invention.  
       FIG. 7  is a top plan view of an embodiment of the present invention.  
       FIG. 8  is a cutaway view of an view of an embodiment of the present invention along line  8 - 8  of  FIG. 6 .  
       FIGS. 8A-8D  are cutaway views similar to  FIG. 8  of various alternative embodiments of the present invention.  
       FIG. 9  is a front view of an embodiment of the present invention.  
       FIG. 10  is a rear view of an embodiment of the present invention.  
       FIG. 11  illustrates the device of  FIG. 1  in one application.  
       FIG. 12  is a prior art nail device.  
       FIG. 13  is a prior art staple device. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      For the purposes of illustrating the preferred embodiments of present invention, the drawings will be described in greater detail.  
       FIGS. 1-4  illustrate one embodiment of the present invention. This embodiment is directed to a retractable attachment device, referred to as a retractable nail  1 . The retractable nail  1  is preferably made of metal or alloy, but it is envisioned that it can be made of plastic or composite or any suitable, durable material. The retractable nail  1  is suitable for attaching a wood floor board  300  to a sub floor  500 , when laying wood flooring, as shown in  FIG. 11 . The joist  600  is shown supporting the sub floor  500 .  
      The retractable nail  1  combines the best advantages of standard nails and screws having a helical thread along its longitudinal surface, such as a wood screw. The retractable nail  1  includes a main head  10  connected to a main body  16 . The embodiment further includes a secondary head  12  connected to the main head  10  with a narrow neck  14  positioned therebetween as illustrated in  FIG. 1  and  4 . The secondary head  12  is configured to break off when the retractable nail  1  is rotated in the counter clockwise direction of the arrows in  FIG. 3  or in a clockwise direction, after the retractable nail  1  is inserted to the wood floor board  300  and the sub floor  500 .  
      The main body  16  stretches along its longitudinal length from the main head  10  and ends at the piercing tip  17 . The main body  16  includes four sides when viewed from the cutaway view of  FIG. 3 , wherein front and rear sides (represented by  FIGS. 9 and 10 ) are separated by two lateral sides (represented by  FIG. 6 ). The front and rear sides include partial thread sections  18 ,  19  separated by the main body  16 . The sides of the main body  160 ,  162  are shown as being substantially planar, but can have various non-planar shapes, as in  FIGS. 8A-8D , including but not limited to any combination of concave, convex, oval, and circular shapes or the like, depending on the material properties of the wood flooring boards into which the retractable nails  1  are to be inserted.  
      One way of viewing the retractable nail  1  is as a modification of standard wood screw having a head connected to a shaft having a piercing point, with a helical thread extending from the piercing point, spiraling around the outer surface of the shaft towards the direction of the head; wherein cutouts are made substantially along the longitudinal length of the shaft to remove portions of the helical thread and preferably the shaft as well, resulting in a device having a cutout view of  FIG. 3  or FIGS.  8 A-D or the like, or a blade-like shape. Thus partial thread sections  18  and  19  correspond to each other, such that when the retractable nail  1  is rotated out of a wood material or the like, including composite materials, a helical bore similar or identical to that which can be created by a wood screw will be formed in the material. The retractable nail  1  has a blade-like shape due to the elongated shapes of the main body  16  with lateral sides thereof missing thread sections, and the elongated shapes of the main head  10  and secondary head  12 , and therefore can be easily inserted into wood floor boards or the like, when dispensed from a nail gun.  
      The partial thread portions  18  and  19  will cause some initial resistance against insertion into the wood floor board  300  or the like, however such resistance is substantially reduced (in comparison to a standard wood screw) due to the narrow width (y) between the front and rear sides of the main body  16 , as shown in  FIGS. 3-5 . The width between the sides  160 ,  162  (x) is preferably substantially larger than the width (y) between the front and rear sides  18 ,  19  of the main body  16 , so that a blade-like cross-section is formed for easy insertion of the retractable nail  1 . Further, the partial thread sections  18 ,  19  should be strong enough to resist substantial deformation during insertion (hammering) into the wood material or the like.  
      The secondary head  12  includes a lower portion  121  which is inserted (hammered) along with the main head  10  into the wood floor board  300  in the manner shown in  FIG. 11 . The secondary head  12  connected to the man head  10  via the neck  14  acts to anchor the retractable nail  1  to prevent the rotation of the retractable nail  1  in the direction or reverse of the arrows of  FIG. 3  by rotative forces exerted on the retractable nail  1  in such active areas as a wood floor.  
      After the retractable nail  1  is inserted into wood floor boards  300  or the like (as in  FIG. 11 ), the nail  1  can be removed by inserting a removal tool, such as a key, into the narrow slot  102  and the removal tool is preferably power rotated in a counter clockwise direction, as in the direction of the arrows of  FIG. 3 . When this occurs, the secondary head  12  which was embedded into the wood floor board  300 , will break off at the narrow neck  14  and separate from the main head  10 , and as the main body  10  is rotated, the partial thread portions  18  and  19  cut into the wood floor board  300  and form a helical thread bore in the wood floor board  300  and the sub floor  500 , just as an ordinary wood screw would when inserted or removed from a block of wood via rotation, thereby permitting the removal of the retractable nail  1  without seriously damaging, destroying or shearing off pieces of the delicate wood floor board  300 . In contrast, the lateral extensions  34  of the prior art wood floor nail  3  of  FIG. 12  are not partial helical thread sections and thus even if the main body  32  were rotated in a manner similar to that of the retractable nail  1 , no helical thread bore will form and the wood floor nail  3  can not be removed from a wood floor board without splitting off portions of the wood floor board and thus destroying the wood floor board to which it is attached to, since the lateral extensions  34  will destroy the wood floor board upon removal. Since it is not possible to remove the prior art wood floor nail  3  by such rotation, there are no need for any equivalent to the slot  102  of the invention for receiving a removal tool in the prior art wood floor nail  3 .  
      The striking faces of the main head  10  and the secondary head  12  are preferably oval in shape, as shown in  FIGS. 1, 2  and  4 , to facilitate easy insertion into the wood floor board, as well as provide resistance so that the main head  10  and the secondary head  12  remain close to the upper surface of the wood floor board  300 , as in  FIG. 11 .  
      The retractable nail  1  permits the correction of mistakes during the wood floor laying process, saving costs for labor and material, without sacrificing efficiency in labor or material costs. The retractable nails  1  can be easily inserted (nailed) into wood materials or the like and yet can be removed without destroying or significantly damaging the material.  
      It is noted that there many different types of wood floor boards, based on their material qualities, i.e. hard or soft wood. Depending on the properties of the wood floor boards used, the retractable nail  1  may require various cross-sectional views other than that of  FIG. 3 , such as shown in  FIGS. 8A-8D .  
      The main head  10  and the secondary head  12  include striking faces  100  and  120  respective, as shown in  FIG. 2 . The striking faces  100 ,  120  are shown to be flat and it is generally so preferred although other shapes including an oval shape may work as well.  
      A removal device in the form of a slot  102  of the main head  10  is preferably shaped to be rectangular or slit-shaped, as shown in  FIGS. 1 and 2 , to minimize its profile, so that the shape of the main head  10  can be minimized to form an oval shape in contrast to a circle shape of most standard nails and screws. A removal tool in the form of a male tool or key can lock into the slot  102  and rotated so that the nail  1  can be unscrewed from attachment to wood material or the like. Alternatively, the removal device may replace the slot  102  with a protrusion (not shown) so that the nail  1  can be removed by a female removal tool.  
       FIGS. 6-10  illustrate another embodiment of the present invention. The retractable nail  2  of this embodiment is similar to that of the retractable nail  1  of  FIGS. 1-5 , absent the secondary head  12  and breakaway neck  14 . Further the shape of the main head  20  of the retractable nail  2  does not have to be of a narrow or elongated or oval shape as in the previous embodiment, but can be configured as a circular shape much like that of a standard screw, as illustrated in  FIGS. 6, 7 ,  9  and  10 .  
      The retractable nail  2  is for general usage, not specific to i.e. application for a nailing wood floor boards. The retractable nail  2  can be used as a substitute for a standard nail or a screw having a helical thread as discussed above.  
      The main head  20  of the retractable nail  2  can accommodate a variety of differing slots  202  into which a removal tool can be inserted and rotated to remove, release or tighten the retractable nail  2  in position in the material it is inserted (nailed) into, preferably by a nail gun as previously discussed with regard to the retractable nail  1 . The slot  202  is shown as having a rectangular periphery in  FIG. 7 , however various other shapes of slots such as one that can receive a Phillips head screw attachment or Allen wrench attachment or the like can be configured on the main head  20 .  
      The retractable nail  2  includes a main body  26  and a piercing tip  27 .  FIGS. 6-10  are similar to the view of  FIGS. 1-5  of the retractable nail  1 . The retractable nail  2  operates in a manner similar to the retractable nail  1 . The retractable nails  2  are nailed into place using a hammer or a powered nail gun, just as ordinary nails. The striking face  200  may be flush with an outer surface of the material to which the retractable nail is secured to.  
      The main body  26  has a front side ( FIG. 9 ), rear side ( FIG. 10 ) and two lateral sides ( FIG. 6 ), as shown in  FIG. 8 . The front and rear sides include rows of segments of a helical thread  28 ,  29  as illustrated in  FIGS. 6 and 8 - 10 . It is noted that the length between the front and rear sides (xx), shown in  FIG. 8 , is greater than the width (yy) between the front and rear sides, as shown in  FIG. 9 , of the main body  26 .  
      As previously discussed the alternative embodiments of  FIGS. 8A-8D  illustrate various potential shapes for the main body  26 , having various combinations of oval or circular cross sections, as well as concave and convex cross-sections. For instance,  FIG. 8A  shows two substantially convex sides  260 ,  262  for the main body  26 .  FIG. 8B  shows a convex and concave side  260 ,  262 .  FIG. 8C  shows the main body  26 , but it could have an oval or elliptical cross-section.  FIG. 8D  shows an alternative shape for the helical thread segements  28  and  29 , with a radial-shaped cutting edge  264 , as well as a smaller cross-section of the main body  26  in comparison to that of  FIG. 8C . The combination of the various shapes for the cross-section of the man body  26  as well as that of the thread segments  28 ,  29 , is to be adapted for a variety of applications, depending on the type of material the retractable nail  2  is to be used.  
      The retractable nail  2  functions similar to the retractable nail  1 . Since the retractable nail  2  lacks the secondary head  20  and breakaway neck of the retractable nail  1 , the retractable nail  2  can be used to tighten or loosen or remove the nail  2  in a material such as wood in the same manner as an ordinary screw with a Phillips head. After the retractable nail has been hammered into place like an ordinary nail, if one desires to tighten the retractable nail  2  in place or remove the nail  2 , a removal tool, such as a key, is inserted into the slot  202  and the removal tool is rotated in the clockwise or counterclockwise direction of the arrows of  FIG. 8 , thus causing the front and rear helical thread sections  28 ,  29  to cut into the material such as wood and form a partial or full helically threaded bore to facilitate in the tightening or loosening or removal of the retractable nail, similar to the operation of an ordinary wood screw having a helical outer thread.  
      The width (xx) between the sides  260  and  262  is substantially larger than the width (yy) between the front and rear sides  28 ,  29  of the main body  26  so that a blade-shaped cross-section is formed as in  FIG. 8  for easy insertion (hammering) of the nail  2 .  
      Hence the retractable nail  2  of the present invention combines the best features of ordinary nails and screws, in that the retractable nail  2  is quickly and easily hammered into place and yet can be tightened, loosened or removed just like an ordinary wood screw (via rotation), leaving in place a partial or full helically threaded bore.  
      The present invention is by no means restricted to the above-described preferred embodiments, but covers all variations that might be implemented by using equivalent functional elements or devices that would be apparent to a person skilled in the art, or modifications that fall within the spirit and scope of the appended claims.