Abstract:
An aluminum floor for fencing has an improved friction surface with traction-enhancing grooves and is configured to reduce noise. Aluminum extrusions forming the floor define a flat surface but with series of parallel grooves separated by non-grooved spaces. In a preferred embodiment the grooves are essentially square cut. The grooves and spaces between the series of grooves are configured so as to allow sliding on the floor with the essentially flat soles of a user&#39;s fencing shoes when desired, but so as to grip the soles with significant friction when the shoe is heavily weighted causing the sole to deform down into the grooves. The fencing floor is intended to lie over an existing floor, as a series of easily connected floor sections. Rubbery sheet material is secured to the bottom of the fencing floor, preferably in transverse strips, directly beneath each joint and preferably at additional locations. When the fencing floor is used over a hard surface such as concrete, the rubber strips prevent the metallic clanging noise typical of aluminum fencing floors in use.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention concerns floors specifically for the sport of fencing, where floor sections of aluminum or other material typically are laid in a linear series to form an elongated relatively narrow floor. More specifically, the invention provides an improved friction surface in an extruded aluminum floor, and also several other improvements including reduced noise in a jointed floor during use. 
         [0002]    The sport of fencing has seen increased popularity in this country in recent years, as well as in Europe, where it has a much longer tradition. Fencing is usually taught and practiced at local clubs, which hold competitions and participate in competitions locally, regionally, nationally and internationally. Fencing is a highly competitive sport that involves elements of speed, finesse, intelligence and strength. It has a growing number of passionate followers in the United States and is an Olympic sport. 
         [0003]    There are three types of fencing: foil, epee and saber. In all three scoring is by valid touches on the opponent, but in foil and epee a touch is made by a thrust against the opponent, while saber involves slashing strokes. A plunger on the tip of the epee and the foil retracts with a valid touch and the score is indicated electronically. In saber fencing there is no plunger but a valid contact between a fencer&#39;s saber and the opponent&#39;s jacket or mask will electrically indicate the touch. Typically there are lights on or near the fencing floor that illuminate whenever a touch is made. In epee fencing the floor is conductive, so that when the floor is touched and the plunger depressed, no touch is electronically indicated. 
         [0004]    The floor or piste on which the fencing competitors stand and perform is very important. The competing area is usually an elongated strip 1.5 meters wide. Although this can be simply laid out with border delineations on a wooden floor, wood is not the ideal surface. The surface should allow for controlled sliding of the foot during all the movements involved in the sport, but for gripping the sole of the foot firmly when full weight is placed upon the foot. At many clubs floor overlays are used, laid in one or more long strips over another floor which may be concrete, wood or other material. 
         [0005]    Several manufacturers make floor overlays or “strips”, including PBT of Hungary (see fencePBT.com) and MultLock, a Turkish company (see multlock-turkey.com). Both make strip aluminum fencing floors formed in one-half meter sections, with a 1.5 meter or 2 meter width. The extruded aluminum sections are formed with a friction surface, and in the case of both PBT and MultLock this high friction surface is achieved by parallel ridges extruded into the floor surface and extending in the lateral (transverse) direction. In both cases these ridges extend above, in upward relief, flat regions of the floor that occur at intervals, and the tips of the ridges are relatively sharp. As a result, the pliable sole of a fencing participant&#39;s shoe tends to be engaged too firmly by the sharp ridges, which deform the shoe sole material and push into the sole. This stops the shoe, and even with only partial weight on the shoe it will prevent the fencing participant from sliding the front foot when desired. 
         [0006]    Sectioned aluminum fencing floors are often laid on concrete or other hard surfaces, and an issue is the clanging noise produced by a fencing competition on such a floor assembled of metal sections. The sections are hooked together but not bolted or otherwise tightly fastened, so there is give at joints, and the very rapid movements and quick footwork of fencing tend to cause aloud metallic noise that seems to be amplified in the acoustic conditions of some facilities. 
         [0007]    It is an objective of the invention described below to provide an improved fencing floor, formed of connectable aluminum sections, with a surface that allows sliding when desired but which provides needed traction when the full weight of the user is placed upon a shoe, and also to make provision for reduction of the noise involved with a multi-section assembled metal fencing floor. 
       SUMMARY OF THE INVENTION 
       [0008]    In the current invention a sectioned aluminum floor for fencing has an improved friction surface with traction-enhancing grooves. Aluminum extrusions forming the floor define a flat surface but with series of parallel grooves separated by non-grooved spaces. In a preferred embodiment the grooves are essentially square cut. The grooves and the spaces between the series of grooves are configured so as to allow sliding on the floor with the essentially flat soles of a user&#39;s fencing shoes when desired, but so as to grip the soles with significant traction when the shoe is heavily weighted causing the sole to deform down into the grooves. As in some previous products, this fencing floor is intended to lie over an existing floor, as a series of easily connected floor sections. Rubbery sheet material is secured to the bottom of the fencing floor, preferably in transverse strips, directly beneath each joint and preferably at additional locations. The rubber strips are spaced such that, for example, only a few inches of floor are unsupported by the rubber strips. When the fencing floor is used over a hard surface such as concrete, the rubber strips prevent the metallic clanging noise typical of aluminum fencing floors in use. In a preferred embodiment the rubbery strips, which can be the material PVC or other soft, extrudable polymers, are engaged in the bottom surface of the extruded aluminum sections by channels formed in the sections and a complementary shaped (T shaped) extension or ridge on each rubbery strip. 
         [0009]    In a preferred form of the invention each floor section is comprised of a series of connected extruded planks that preferably engage with a hook-like connection in side by side relationship with one another and also are retained in position together by border or frame pieces that receive the edges of the planks in a close fitting channel (and preferably with adhesive), and with welds between some of the planks and the border or margin piece, at prescribed spacings. 
         [0010]    Another preferred feature is that the border or margin strip has a channel at bottom that normally receives a rubber cushion strip but receives a threaded nut slidable through this channel, and this border strip is tapered downwardly at the outer edge. The nut is engaged by a machine screw at a location where the rubbery cushion is interrupted, to grounding lug. The grounding lug is crimped to a wire to carry the ground terminal of the electrically conductive floor. Thus, the same extruded channel providing for a slide-in rubber cushion also provides for the grounding lug. 
         [0011]    A further feature in one preferred embodiment is a C-shaped channel formed at the outer edge of the border strip, formed during the extrusion process and opened outwardly. In this C-shaped channel can be installed an LED light tube. Wiring can also be contained in the same channel, just interior of the light tube. The LEDs of the light tube can be illuminated whenever a point is gained by proper fencing contact by one of the competitors. 
         [0012]    Accordingly, primary objects of the invention are to improve the traction characteristic of an extruded metal fencing floor and to reduce or eliminate the metal clanging noise typical of such floors assembled in sections. 
         [0013]    It is thus among the objects of the invention to reduce noise in a fencing floor assembled from a series of linked aluminum sections, and to provide a better surface for interaction with shoes of the users, particularly in an extruded aluminum, electrically-conductive floor. These and other objects, advantages and features of the invention will be apparent from the following description of a preferred embodiment, considered along with the accompanying drawings. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  is a perspective view showing a fencing floor of the invention, as laid over an existing floor. 
           [0015]      FIG. 2  is a plan view showing two floor sections of the floor system not in correct proportions of the invention, including an end section. 
           [0016]      FIG. 3  is a sectional view showing a preferred form of extruded plank for the floor section, one of a series of planks secured together to form a section or panel. 
           [0017]      FIG. 4  is a sectional view showing a frame or margin strip, an extruded metal piece that frames the floor section and retains the planks in position. 
           [0018]      FIG. 5  is a view showing the underside of a floor section, including rubber strips secured to the extruded metal members of the floor section. 
           [0019]      FIG. 6  is a bottom perspective view showing a grounding lug and the manner of its securement to a frame piece of a floor section. 
           [0020]      FIG. 7  is a sectional view showing a modification of the extruded margin strip for accommodating an LED light tube. 
           [0021]      FIG. 8  is a side elevation view in section showing a recessed installation of a fencing floor. 
       
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0022]    In the drawings,  FIG. 1  schematically shows a room to be used for fencing competition, and indicates several floor strips  10  for fencing. These floors, pursuant to rules, typically are 1.5 meter in width and of an elongated length as shown the official length being 14 meters. The fencing floors  10  are laid down over an existing floor  12 , which may be wood, concrete, etc. In some cases the laid-down floor  10  may be wider, such as two meters wide, with a painted stripe along each edge, each 0.25 meter wide, to show the limits of the useable width of the floor. 
         [0023]    The floor  10  of the invention is formed as a series of assembled sections that are conveniently laid in place to form the elongated fencing floor  10 . These sections, which may each be one half or one meter in length, preferably include two end sections which have terminating edges. The edges at all four sides of the floor  10 , in a preferred embodiment, are tapered so as to slope downwardly toward the existing floor  12 . 
         [0024]      FIG. 2  shows two of the panels, an end panel  14  and a typical field panel  16 , in plan view. Each panel  14 ,  16  in this preferred embodiment is made up of a series of assembled, parallel, side-by-side floor planks  18 . These planks  18  are connected together and are retained in place by margin or frame strips  20  (sides) and  22  (ends of end panels  14 ). All of the planks and strips  20 ,  22  preferably are aluminum extrusions. 
         [0025]      FIG. 3  is a cross section view showing a single plank  18  of the fencing floor and of a panel  14  or  16  illustrated in  FIG. 2 . The cross section plane is longitudinal with respect to the length of the fencing floor, thus crossing transversely through the length of a plank  18 . The extruded metal (preferably aluminum) piece  18  has a curving extension or protrusion  24  at one end, extending through the length of the extrusion. This connects in a hooking relationship into a complementarily shaped socket  26  of a succeeding plank, also shown at the opposite of the illustrated plank  18 . The thickness of the metal may be about 6 mm in a center section  28  and about 9 mm at floor-engaging bosses or bases  30  at one end and  32  at the opposite end. 
         [0026]    As illustrated, the plank  18  has, at each of the bosses  30 ,  32 , a channel  34  which slidingly receives a rubbery cushion sheet or strip  36 , which can be soft, extrudable PVC. This sheet or strip may be, for example, about 2 to 3 mm in thickness. It has a generally T-shaped ridge or flange  38  integrally formed at its upper side, sized or configured to slide into the complementarily shaped channel  34 , with little friction. These strips or sheets  36  frictionally engage the fixed floor and cushion the engagement of the panels or sections against the floor, which may be of concrete or wood, and prevent noise at joints between sections or between the metal and the floor as the fencing floor is used. The planks  18  preferably fit together with relatively close tolerance at the joints that are formed by the curving extension ridges  24  fitting into the curved channels  26 , and under each joint between panels or sections  16  is a strip of the rubber material  36 . In a preferred implementation of the invention the rubbery cushioning strips  36  are located at every joint between planks  18 , so that in the case of plank widths of 10 cm and section lengths of one meter, there are ten of the rubbery cushioning strips in each section or panel. The strips could take alternative configurations or could be employed less frequently (at greater spacing) if desired. Larger sheets could be used, and each sheet could connect with more than one of the extruded channels  34  of the planks. 
         [0027]      FIG. 3  shows that the planks  18  have, in a preferred embodiment, grooves  37  formed down into the surface. These grooves  37  extend lengthwise of each plank  18 , but transversely relative to the length of the fencing floor  10 . It is important that these grooves are formed down into the surface of the plank, the surface being defined by non-grooved spaces  39  between each series of grooves  37 , and also by the plank surface immediately between adjacent grooves  37 . Prior fencing floors have included ridges which extend upwardly from the surface of the floor, and these can cause problems as described above. The system of grooves  37  and spaces  39  between grooves as encompassed by the invention solves this problem as described above. In a preferred embodiment the total surface area occupied by or defined by the grooves themselves is about 31% of the total floor surface. More broadly, it is preferred that the total area occupied by the recesses or grooves is about 25% to 30% of the floor surface, but more preferably the recessed area is within 2% to 4% of the 31% preferred figure noted above. 
         [0028]    As seen in the drawings, the grooves  37  are in series. Each series  37   a , which may have about eight recesses, in a preferred embodiment, spans about 12 to 25 mm along the floor as measured in the length direction of the floor, and preferably each space  39  between series of grooves spans about 7 to 15 mm as measured in the length direction of the floor. More preferably each series  37  of grooves recesses is about 22 mm wide and each space  39  between series of grooves spans about 11 mm. Each groove or recess  37  may be a little over 1 mm in width, preferably in the range of about 1.25 mm to 1.3 mm in width and may be approximately 0.5 mm in depth (preferably about 0.3 to 0.9 mm depth). As explained above, these recesses or grooves enhance traction in a surface which is otherwise flat and allows the fencing user to slide forward with his front foot. 
         [0029]    Each panel or section  14  has, via the planks, a hooked flange or protrusion  24  at one end (male) and a hooked channel or socket (female)  26  at its opposite end. To assemble the sections the male end of one section is angled downwardly to assemble it into the adjacent, already-laid section. 
         [0030]      FIG. 4 , a cross section looking in the longitudinal direction of the floor taken along the line  4 - 4  in  FIG. 2 , shows the manner in which the frame or border pieces  20  firmly engage with the edges of the planks  18 . The ends of these planks extend into a channel  40  preferably in a tight, interference fit, and they are also secured by an effective metal adhesive such as SikaFlex 1A polyurethane adhesive manufactured by Sika Corp. of Lyndhurst, New Jersey. They may extend into the channel about 1.5 to 3 cm, for example, and most preferably about 2 cm. To increase the firmness of the grip between the frame piece  20  and the planks, the channel  40  may include “teeth” or ridges  41  that extend lengthwise of the border piece  20  and are somewhat malleable and deformable when the border piece  20  is forced over the series of connected planks. The outer edge of the frame or margin connector piece  20  is tapered downwardly toward the outside at  42 , to form a transition up from the fixed floor onto the platform of the fencing floor. As also shown in  FIG. 4 , the margin or border piece  20  is extruded with a channel  44  in the bottom, near the outside edge, to receive a cushioning elastomeric strip  46 . This rubber-like strip  46 , retained in the channel  44  preferably by a T shape upper extension  46   a  as shown, provides, along with the rubbery elastomeric strips  36  connected to the bottoms of the planks and extending laterally, positive friction engagement with the floor and cushioning that both gives a better feeling to the floor surface and reduces or eliminates the clanging of metal against metal when the floor is in use. 
         [0031]      FIG. 4  also shows that the top and inclined surfaces of the frame or border piece  20  preferably have grooves  48  formed down into the surface in the extruding process. These provide good traction for persons entering or leaving the fencing floor and for participants who may step near the edge of the floor. 
         [0032]    The frame or margin piece  20  therefore retain the edges of the planks very firmly, in a tight fit with the channel  40 . However, as shown in  FIG. 5 , some of the planks  18  preferably are fixed as by welding to the border strip  20  at the bottom side.  FIG. 5  indicates welds  50 , which can be applied only at the ends of a section or panel (which may be one half or one meter long), assuring that the planks cannot separate or work their way loose.  FIG. 5  also shows the rubbery strips  36  retained to the bottom side of the panel, which can be at intervals of one strip for each plank. Also, the drawing shows the rubbery cushion strip  46  which is fitted into the margin or frame piece  20  as shown in  FIG. 4 .  FIG. 5  illustrates one of the two end panels or sections, and shows that the border or frame pieces  20 ,  22  can be mitered together at corners  52 , and the rubbery margin-connected strips  46  may also be mitered or can simply be abutted together at corners. 
         [0033]    The fencing floor of the invention can advantageously include several additional features.  FIG. 6  shows how the margin or border piece  20  or  22  can be used to secure a grounding lug  55  to the metal floor. The floor should be grounded for scoring purposes, for epee. The grounding lug  55  is placed in an interruption of the rubbery cushion piece  46 , with a machine screw  58  passing through the grounding lug&#39;s aperture and down through the slot  60  that is part of the extruded channel  44 . A nut (not seen in the drawing) is assembled into the deeper slot  62  at the interior side of the channel  44 , to the position where it can be engaged by the machine screw  58 . 
         [0034]      FIG. 7  shows a modified form of border or frame strip  20   a . It is similar to the border strip  20  shown in  FIGS. 4 and 6 , but has a C-shaped cavity  65  at the outside edge, to retain an LED light tube  66 . Thus, the entire border of the fencing floor can be provided with such an LED light tube, snapped into the cavity  65  and wired so as to be capable of illumination to indicate when a point is scored. If desired, the cavity  65  can have a further recess  68  to run wiring, so that the wiring can be laid first into the inner recess or cavity  68 , then the LED light tube  66  can be snapped into the outer recess  65 , capturing the wiring in place. 
         [0035]    It is also possible to install a floor according to the invention without a border strip  20 ,  22 , as a recessed installation in an existing floor. This can be in new construction or in an existing floor. If, for example, an existing floor has wood flooring over some type of subfloor, the planks  18  can be installed in a recess formed where the flooring is removed. The flooring can be cut out of an existing floor, or in a new installation an appropriately-sized recess can be left for this purpose.  FIG. 8  shows one method for laying a fencing floor of the invention in such a recess, so as to provide an inlaid fencing floor. The planks  18  are shown with the rubbery cushion strips  36  supporting them against a subfloor or underfloor  70 . In the case this underfloor is of wood, the rubbery strips  36  can be progressively installed by using nails  72  (concrete nails could be used in a concrete floor). The existing finished floor is shown at  74 , and has been cut out as indicated at  76 . A portion of the plank  18  on the left is shown cut away and foreshortened. 
         [0036]    The installation of  FIG. 8  starts with the plank that would be left-most as seen in the drawing, the planks being arranged with their length extending into the page, the widths being shown in cross section in the drawing. The left-most plank  18  is first laid down, with a rubbery cushion strip  36  or a portion secured to that side of the plank. This first strip  36  can be secured by gluing or by nails without being secured to the plank itself. If desired the hook end  24  at the left side of this plank can be removed prior to installation; however, this hook end  24  could be used to anchor the left side of the plank, if a groove (not shown) were formed in the end  76  of the floor  74  to receive this hook end, avoiding the need for any adhesive attachment. 
         [0037]    When the first plank  18  is lowered into place, it includes a rubbery cushion strip  36  at its right side, as shown, fitted into the metal extrusion as the figure reveals. When the plank is down, the rubbery strip extends cut to the right as seen in the drawing, and this extending end is nailed down with a series of nails  72 . Next, the next succeeding plank  18  is laid down, hooked onto the installed plank, with a cushion strip  36  already secured on its right side. This outer end is swung down onto the subfloor  70 , and again the nails are installed through the outwardly extending cushioning strip. This process continues until the floor has been fully installed across the recess. For the last plank (which would be to the right in  FIG. 8 ), the rubbery strip can be secured to the subfloor by adhesive. It should also be understood that all rubbery strips can be secured to the floor by adhesive, if desired, although fasteners generally are preferred. 
         [0038]    In this installation the planks  18  are the full width of the fencing floor, i.e. preferably 1.5 meter (or 2 meters as noted above). 
         [0039]    The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.