Floor Covering Patents (Class 33/527)
  • Patent number: 6935037
    Abstract: An apparatus for tracing a contour onto a tile prior to cutting the tile includes a base member having a first longitudinal slot and a retaining lip disposed at one end thereof. A first extension member includes a second longitudinal slot and is pivotally attached to the base member by a fastener assembly that passes through the first and second longitudinal slots. A second extension member includes a third longitudinal slot and is pivotally attached to the first extension member by a second fastener assembly that passes through the second and third longitudinal slots. The second extension member includes a 45 degree angled end that terminates in a point, the point being useful for locating a point on an obstruction. The 45 degree end is used to orient the first and second extension members at a 45 degree angle with respect to a raised edge of the base member.
    Type: Grant
    Filed: March 31, 2003
    Date of Patent: August 30, 2005
    Inventor: Arthur Garcia
  • Publication number: 20040250435
    Abstract: A tile spacer (10′) comprises a support portion (12′) adapted to overlie, preferably contact, at lease one tile with a lower face (20′) of the support portion opposed to an exposed face of the tile or tiles, and a plurality of individual first tile separator elements (14′) carried by the support portion and projecting downwardly relative to said lower face (20′). Each of the first tile separator elements (14′) is spaced from the other element or elements (14′) and has opposite surfaces which abuts opposed edges of adjacent tiles in use to space said tiles. The spaces (10′) may also have opposed second tile spacer elements (16′) that are used to space tiles in a corner. A method of use of the tile spacer is also disclosed.
    Type: Application
    Filed: April 15, 2004
    Publication date: December 16, 2004
    Inventor: Tony Mark Fiore
  • Patent number: 6796049
    Abstract: An adjustable tile spacing apparatus permits the setting tiles in a consistent pattern with perfect spacing relative to one another so as to obtain grout joints of uniform width. The adjustable tile spacing apparatus includes a central member and two perpendicular members at opposing ends of the central member, with each member adjustable in both width and length dimensions, via the use of telescoping members and fasteners. A spacer is affixed to each corner of the apparatus. The spacer can have an X-shape, a T-shape, an L-shape, or a linear shape. The spacers may be ¼ inch, ⅜ inch, and ⅛ inch in width to construct various sized grout line widths. A rubber handle with finger grips is provided for user comfort. The adjustable tile spacing apparatus is simply moved along as each tile is set and provides perfect spacing for the next tile to be set.
    Type: Grant
    Filed: March 18, 2003
    Date of Patent: September 28, 2004
    Inventor: Curtis A. E. Claxton
  • Patent number: 6647685
    Abstract: A tool for the spacing of tiles during installation includes a central body with radially projecting prongs that are fitted between adjacent tiles to control the spacing thereof.
    Type: Grant
    Filed: January 10, 2002
    Date of Patent: November 18, 2003
    Assignee: Space-It-Rite
    Inventors: Joseph L. Annarella, Robert Grzybowski, John F. Dumelle
  • Patent number: 6625951
    Abstract: A system for laying and leveling a tile walking surface, i.e. indoor floor or outdoor patio or pathway, where the system relies upon the use of inserts embedded within the adhesive for securing the tile. A preferred insert is a single plastic member, preferably circular in configuration, and contains plural through openings for receiving and securing the insert into the adhesive. Optionally, removable space dividers may be provided where the space dividers are initially positioned in the openings for spacing adjacent tiles, then removed to allow grouting of the spaces. Alternately, the insert may be a two-piece member that can be vertically adjusted where needed to ensure a level substrate and hence a level walking surface.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: September 30, 2003
    Inventor: Lawrence McCarthy
  • Patent number: 6481112
    Abstract: A tile fitting device is provided for use in marking and cutting a loose tile of a predetermined size to be marked to permit it to be laid on a narrow untiled floor space disposed between an upright wall surface and confronting outer edge of a plurality of like laid tile of a predetermined size on a contiguous tiled floor space.
    Type: Grant
    Filed: September 5, 2001
    Date of Patent: November 19, 2002
    Inventor: David White
  • Publication number: 20020069546
    Abstract: And adjustable tile spacing apparatus is provided for laying tiles in a consistent pattern with perfect spacing relative to one another so as to obtain grout joints of uniform width.
    Type: Application
    Filed: December 13, 2000
    Publication date: June 13, 2002
    Inventor: Curtis A. E. Claxton
  • Publication number: 20010034946
    Abstract: A leveling tool including a screed bar and a scraper blade. The screed bar includes either a slot or a bracket to slightingly accommodate the scraper blade. These grape or blade is vertically adjusted within the slot or bracket to a desired height and may be fixed at the desired height by inserting bolts through aligned holes. Once the leveling tool has been adjusted to a desired height, the soil surface proximate the land escaping block can be planed or leveled at an elevation to enable a second block to be placed next to the first block, the tops of the blocks being level.
    Type: Application
    Filed: March 28, 2001
    Publication date: November 1, 2001
    Inventor: Duane Hamdorf
  • Patent number: 6195904
    Abstract: A tile measuring device including a pair of transparent, slidably connected plates having reference indicia thereon. A rotatable handle, defining a threaded aperture, is mounted on a threaded member, fixed to the bottom plate, and is rotatably adjustable from a first position wherein the top and bottom plates are fixedly secured relative to one another, to a second position wherein the top and bottom plates may be slidably adjusted. The top and bottom plates each include linear dimension markings along at least one side of the device such that when the top and bottom plates are telescopically adjusted and fixed relative to one another the markings provide linear dimension references. In addition, each of the top and bottom plates include longitudinal markings for use in cutting notches in tiles.
    Type: Grant
    Filed: April 7, 1998
    Date of Patent: March 6, 2001
    Inventor: Bret M. Greer
  • Patent number: 6112424
    Abstract: An instrument board (21) with a thin base (26) and top surface of base for placing tile to be measured for cutting, tracks (27) at front and rear atop base and tile placing surface between tracks, a pilot hole (31) in both ends of each track, a pair of measuring arms (23) that insert into pilot holes at sides of board with a peg (25) in each arm at measuring point (38), a straight edge (24) is placed at measuring points (38) on arms for a reference line (37) and a sliding member (22) that attaches to tracks, a measuring arm (23A) that installs into sliding member to measure uneven structure bases for tile laying and a corner measuring arm (23B) that installs into sliding member to measure corner area for tile laying and alignment guides (28) to align board front and alignment marks (29) to align board sides with seams of laid tile and a cutting surface (32) insert that installs atop base for cutting vinyl flooring tile, a spacer (33) and a spacer (34) for reducing width of tile placing area atop base, to prov
    Type: Grant
    Filed: March 18, 1998
    Date of Patent: September 5, 2000
    Inventor: Howard Lee Friend
  • Patent number: 6101730
    Abstract: A marking indicator template jig for marking a tile to be cut and positioned in an open area of a size smaller than a size of the tile. The jig includes first and second legs pivotally connected together. A first telescoping leg is pivotally connected to a second end of the first leg and a second telescoping leg is pivotally connected to a second end of the second leg. The first and second telescoping legs each have an adjustable length. The marking indicator template jig is movable between a first unextended position and a second extended and in use position wherein the first and second legs are positioned within an open area smaller than the tile and against adjacent tiles defining a first portion of the open area and the length of the first and second telescoping legs are adjusted to meet an obstruction defining a second portion of the open area such that the marking indicator template jig is of a dimension substantially equal to that of the open area for use in marking the tile for cutting.
    Type: Grant
    Filed: June 12, 1998
    Date of Patent: August 15, 2000
    Inventor: Vincent A Marino
  • Patent number: 5832619
    Abstract: An adjustable frame for simultaneously aligning and installing multiple tiles. The adjustable frame contains a plurality of tile apertures. Each tile aperture is sized to accept a particular tile size. Tiles are inserted into each of the tile apertures to allow multiple tiles to be installed and automatically be aligned with one another during the installation process. The width of the grout area between the tiles is thus automatically set by the width of the adjustable frame segments. The adjustable frame is fabricated from independent frame segments which have internal adjustment rod channels. Adjustment rods are adjustably secured to two frame segments such that the distance between the frame segments can be selectably varied. By varying the distance between frame segments, the size of the tile aperture is varied, and therefore the tile size can be varied. The size of the tile apertures can be independently varied in a lateral direction or in a longitudinal direction.
    Type: Grant
    Filed: October 7, 1996
    Date of Patent: November 10, 1998
    Inventor: Charles L. Volkema, Jr.
  • Patent number: 5768793
    Abstract: An adjustable template is illustrated having an elongated continuous guide (A) carrying a number of longitudinally spaced blocks (B) for accommodating floor tiles 25 of various widths, lengths and thicknesses. The blocks are manually adjustable on the longitudinal guides by adjustment of the threaded fasteners (C). The height of the legs (E) is vertically adjustable within receptacles (D) carried by a respective block on each side of the elongated guide (A). The method contemplates the laying of a single longitudinal row of tiles 30 while maintaining a next previously layed row of tiles 31 preparatory to laying and positioning of an additional row of tiles by movement of the apparatus across the previous longitudinal row of tiles.
    Type: Grant
    Filed: September 9, 1996
    Date of Patent: June 23, 1998
    Inventor: Timothy S. Fields
  • Patent number: 5701680
    Abstract: A tile setter's measuring tool includes a cup slide in the form of an elongate bar having a through-extending passageway along a substantial proportion of its length and a pivot mount at one end, an object guide pivotally mounted to the pivot mount, and a tile cup block slidably engaged to the cup slide by a fastener passing through the passageway, permitting positioning of the tile cup block at a desired orientation and location along the passageway, the tile cup block having an upper surface and a lower surface, each of the upper and lower surfaces being provided with spacers in arrangements that differ from one another.
    Type: Grant
    Filed: August 13, 1996
    Date of Patent: December 30, 1997
    Assignee: TNT Tools, Inc.
    Inventors: Glenn M. Garcia, Robert E. Diller
  • Patent number: 5617642
    Abstract: Disclosed is a method and device for fitting tile and other building material into a mosaic pattern. A base section is connected to a slidable and rotatable rod connected to one or more cut line adjustment rods which conform to a particular pattern for cutting the tile. The base section is mounted flush with an edge and the rods are positioned to conform to an obstruction or other cut out to be cut into the tile. The adjustment rods are then fixed in place, the device is laid over a tile, and the cut lines are made on the tile by tracing the cut line pattern from the device. The tile is cut along the cut line pattern and fitted into the mosaic pattern.
    Type: Grant
    Filed: July 24, 1995
    Date of Patent: April 8, 1997
    Inventor: Ioannis E. Marios
  • Patent number: 5546668
    Abstract: A contour tracing device provides a housing unit which holds a series of parallel probe rods. The rods extend from the housing side walls, and are restrained to sliding, linear motion with respect to the housing. When the ends of the rods are pressed against a surface, they move relative to the housing so as to reflect the surface's contour and maintain their position until manual pressure is again applied. The device may include a lever for locking the rods in a desired configuration, thus preventing the rod positions from being inadvertently altered. The tracing device may include a level indicating device.
    Type: Grant
    Filed: March 31, 1995
    Date of Patent: August 20, 1996
    Inventor: Ned M. Ahdoot
  • Patent number: 5483749
    Abstract: Apparatus for cutting tiles or similar items to size comprises a measuring device having first and second measuring members which are movable towards and away from each other to set a required size to which a tile is to be cut, a cutting device comprising a base, a cutter, and a guide for guiding movement of the cutter along a defined path across the base, and a formation on the base to receive the first measuring member of the measuring device and to position the same in alignment with the defined path, whereby a tile placed in edge contact with the second measuring member of the measuring device is automatically positioned for cutting substantially to the required size by the cutter. The formation preferably comprises a recess in the base, such that when received in the recess an upper surface of the first measuring member lies substantially flush with an upper surface of the base.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: January 16, 1996
    Assignee: Plasplugs Limited
    Inventor: Paul S. Hepworth
  • Patent number: 5471758
    Abstract: A tile measuring device for use in laying tiles is disclosed comprising a support member, a reference member portion, and a measuring member portion. The reference member portion is slidably coupled to the support member for establishing a reference position for the device with respect to a tile and second tile. The measuring member portion is movably coupled to the support member at a distal end thereof for defining a portion for removal from the second tile relative to the reference position. Removal of this undesired portion from the second tile permits the second tile to fit properly adjacent an obstruction after the undesired portion is removed.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: December 5, 1995
    Inventor: Dennis P. White, Sr.
  • Patent number: 5410816
    Abstract: A body, having a straight-edged rule fixed thereto, and transverse thereto, slidably receives a pair of blocks which also have straight-edged rules fixed thereto. All the rules are parallel, and one thereof is used to engage a proximate wall surface, while the other two are adjustably set to take the measure across a last-laid tile. Then, the first, which engages the wall surface is fully retracted, while the adjustably-set other two rules are advanced, with the body, to the wall surface. The outermost rule, then, along its straight edge, defines whereat a next tile is to be cut to fit an undersized space.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: May 2, 1995
    Inventor: Joseph Ruggiero
  • Patent number: 5363560
    Abstract: In the thin set laying of stone or ceramic tile, tiles are set by floating them over a uniformly applied screed of adhesive applied to a level substrate. In this invention combination spacing/levelling devices are used to equally space the corners of adjacent tiles and to maintain them at an equal elevation over the adhesive and substrate. The spacer/leveller device may comprise spacing fins and a guide for maintaining the corner of adjacent tiles flush while mortar is setting. The device works as a guide to facilitate level installation with uniform grout joints and it becomes part of the permanent fabric of the installation. Tiles are temporally supported by spacer/levellers at each corner (while adhesive is drying) and by virtue of the spacer/leveller design they are automatically flush to each other with equal joint spaces separating them. The invention substantially reduces the dependence on the skill of the tile layer to space tiles equally and set them on the same horizontal plane.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: November 15, 1994
    Inventor: Stan P. Makow
  • Patent number: 5361508
    Abstract: A body, having a straight-edged rule fixed thereto, and transverse thereto, slidably receives a pair of blocks which also have straight-edged rules fixed thereto. All the rules are parallel, and one thereof is used to engage a proximate wall surface, while the other two are adjustably set to take the measure across a last-laid tile. Then, the first, which engages the wall surface is fully retracted, while the adjustably-set other two rules are advanced, with the body, to the wall surface. The outermost rule, then, along its straight edge, defines whereat a next tile is to be cut to fit an undersized space.
    Type: Grant
    Filed: August 30, 1993
    Date of Patent: November 8, 1994
    Inventor: Joseph Ruggiero
  • Patent number: 5359783
    Abstract: A spacer for use in laying tile to produce grout joints having constant width includes a pair of cross-members which form four quadrants to receive four tiles. The spacer can be used with different sizes of tiles.
    Type: Grant
    Filed: July 20, 1993
    Date of Patent: November 1, 1994
    Inventor: Freddie Smith
  • Patent number: 5353508
    Abstract: A border cutter for use with a cutter blade carrier for cutting a strip of carpet, the carrier having a blade plate for a cutting blade, the border cutter including a surface plate for movement along a piece of carpet, and having a guide edge and a cutting blade opening normal to the guide edge, and having spaced guides with aligned slots for receiving the carrier plate for positioning a blade at the blade opening. The spaced guides extend parallel to the blade opening, with each guide having a plurality of slots extending therealong in alignment with the slots of the other guide, providing a plurality of locations on the surface plate for the blade carrier. One of the spaced guides includes a channel for receiving a guide toe plate of a blade carrier support of the blade carrier.
    Type: Grant
    Filed: April 29, 1993
    Date of Patent: October 11, 1994
    Assignee: Roberts Consolidated Industries, Inc.
    Inventor: David H. Baker
  • Patent number: 5293694
    Abstract: The devices disclosed herein are designed for the purpose of properly spacing tile from each other to provide the desired width of space between tiles to give the desired grout line. The first device has a length sufficient to span the length or width of at least three tiles and likewise has a lip extending downward from a linear edge thereof. The second device has a lip extending downward from a flat rectangular plate having a length shorter than the length of the individual tiles. Both of these lips have identical thicknesses to give the desired grouting space between individual tiles. In preferred modifications of these first and second devices a second lip extends upwardly at the opposite parallel edge from the edge having the first lip. By having the thickness of this second lip of a different thickness from that of the first lip, the second lip can be converted to a downwardly extending lip by inverting the devices and used to give a different dimension to the width of the grout line.
    Type: Grant
    Filed: February 12, 1993
    Date of Patent: March 15, 1994
    Inventor: James Swindle
  • Patent number: 5288534
    Abstract: A tile spacer includes a platform (10) having opposite coplanar surfaces (11, 12) on which are disposed a straight spacer (13) and a corner spacer, either a cross-shaped spacer (14) or a tee-shaped spacer 15, respectively. One leg of the corner spacer (14, 15) is coaligned with the straight spacer (13) so as to assist in aligning either of the spacers while using the other spacer as a handle. The spacer (13) and the coaligned leg of the spacers (14, 15) may extend beyond the platform so as to assist aligning the spacer (13) when using the spacer (14, 15) as a handle.
    Type: Grant
    Filed: December 28, 1992
    Date of Patent: February 22, 1994
    Inventor: B. Armen Tavshanjian
  • Patent number: 5188013
    Abstract: A vinyl tile spacing gauge and cutter for the measuring and scoring of an edge floor tile, such device having a heated plate surface on which the tile is positioned and a pair of extendable measuring arms adapted to extend from the base of the device from the edge of a central flooring tile to an adjacent wall to determine the dimensions to cut the tile and a scoring arm positioned above the heated surface slideably adjustable to cut the tile at a selected position, such heated surface having a measurement grid delineated thereon for the positioning of a tile in relation thereto and in relation to the dimensions obtained from the measuring arms.
    Type: Grant
    Filed: September 3, 1991
    Date of Patent: February 23, 1993
    Inventor: Douglas Cardinale
  • Patent number: 5181326
    Abstract: Disclosed is a tool for marking tiles having a predetermined thickness, so that the tiles may be cut precisely to enable them to be placed adjacent each other and spaced apart a predetermined, uniform, distance corresponding to the thickness of a desired grouting thickness. The tool includes a generally flat, elongated, rectilinear bar having a pair of opposed ends, a pair of opposed sides, and generally flat top and bottom opposed faces. A plurality of different sized slide elements are selectively used with the bar depending of the desired thickness of the grouting. Individual ones of the slide elements are adapted to be carried by the bar and movable along the length of the bar between the ends and removed from the bar by sliding off an end. Each of said slide elements have a body member which is supported by the top face and has a pair of opposed arms extending along and bearing against the sides. The arms have a height less than the thickness of the tile.
    Type: Grant
    Filed: December 23, 1991
    Date of Patent: January 26, 1993
    Inventor: Joseph Eberline
  • Patent number: 5134785
    Abstract: A method and apparatus to measure the loop height in a loop pile fabric by moving an apparatus across the surface of the fabric and allowing the loops to create a line on a powdered surface to which a finger is aligned with to cause the plunger of a gauge to automatically provide a read-out of the loop pile height.
    Type: Grant
    Filed: October 1, 1991
    Date of Patent: August 4, 1992
    Assignee: Milliken Research Corporation
    Inventor: Michael W. Gilpatrick
  • Patent number: 5038490
    Abstract: A ceramic tile gauge for determining the shape of a space between a fixed tile and an adjacent fixed member and for enabling a tile to be cut to the shape of the space comprises a body member having an abutment surface thereon and a pair of arm members extending rearwardly of the body member. A pair of engagement means are slidably mounted one on each arm member to be selectively and releasably lockable to the arm members whereby, with the abutment surface engaging the fixed member and with the engagement means located and locked in operative positions on the arm members and in engagement with the bounding edge of the fixed tile, the abutment surface and a straight line through the engagement means define opposed edges of the space.
    Type: Grant
    Filed: May 1, 1990
    Date of Patent: August 13, 1991
    Assignee: Creative Products & Development Limited
    Inventor: Derrick Armstrong
  • Patent number: 4899455
    Abstract: A tile squaring device comprising: a distance rod; an anglehead having a first connector means and a second connector means disposed in such a way that a first straight edge extension and a second straight edge extension may be attached to the first and second connector means, respectively, at a right angle to each other; and a squaring means for connecting the anglehead to the distance rod such that the anglehead is positioned at a right angle off of the distance rod.
    Type: Grant
    Filed: January 6, 1989
    Date of Patent: February 13, 1990
    Inventors: Alessio A. Bovino, Robert C. Bitting
  • Patent number: 4827625
    Abstract: A template for cutting floor-covering tiles or the like. The template comprises a deformable frame having five flat strips which are fixed together end-to-end, said strips comprising: (a) a thrust strip (1) provided with a positioning abutment (10); (b) two side strips (2, 3) capable of sliding perpendicularly to the thrust strip (1); and (c) a set of two line-of-cut strips (4, 5) which are hinged to each other, and which are also hinged to the ends of the two side strips (2, 3) by means of shafts (21, 31) capable of longitudinal sliding relative thereon; locking members (15, 16) being provided to enable the set of strips (1, 2, 3, 4, 5) to be locked in any desired mutual position. This instrument is used for cutting peripheral tiles when laying a covering on a floor, a wall, or a ceiling. The invention is particularly applicable to carpet tiles.
    Type: Grant
    Filed: December 18, 1987
    Date of Patent: May 9, 1989
    Inventor: Yannick H. V. Le Moal
  • Patent number: 4809439
    Abstract: A carpet scribing device and gauge for measuring the size of a carpet module adjoining a baseboard. The device comprises a rod on which is slidably mounted a block encased in a bracket having a dependent portion which abuts against the edge of laid carpeting. The end of the rod which abuts against the floor board is provided with a needle extending angularly downwardly with its point in vertical alignment with said end of the rod. By reversal of the block on the rod, the device is useful for carpeting stairs.
    Type: Grant
    Filed: October 21, 1987
    Date of Patent: March 7, 1989
    Inventor: Lawrence J. Burns
  • Patent number: 4776100
    Abstract: A cutting guide for use in cutting and fitting carpet has a first planar portion for detachable securement to a carpet and a second, marking portion attached thereto with a working or marking edge for use in transposing the location of a wall/floor edge or the like to the carpet to be cut, when the second, marking portion is positioned along the wall/floor edge and is detachably secured at that location by the carpet.
    Type: Grant
    Filed: February 26, 1987
    Date of Patent: October 11, 1988
    Inventor: John Brumley
  • Patent number: 4733477
    Abstract: A chalk line framing square is provided to aid in placing right angle intersecting chalk lines upon a floor so that tiles can be properly installed on the floor. The framing square can check the squareness of the tiles as they are installed without being placed in the adhesive.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: March 29, 1988
    Inventors: James R. Fincham, George Spector
  • Patent number: 4712309
    Abstract: The template described herein comprises one that is adjustable to be suitable for use with tile of various sizes. A first series of parallel longitudinal bars are dovetailed with a second series of lateral bars positioned perpendicularly to the bars in the first series. The positioning of the bars can be adjusted to give the desired individual spacing for each tile and the bars can be fixed to each other to give sufficient rigidity for use as a template and sufficient rigidity to allow lifting of the template.
    Type: Grant
    Filed: April 16, 1987
    Date of Patent: December 15, 1987
    Inventors: Arthur G. Kingston, Carl R. DeLong
  • Patent number: 4659409
    Abstract: A template of translucent material is employed to simulate on a reduced scale the over-lay material to be applied to a floor area as it is illustrated by a drawing on the same scale as the template. The template is supplied in roll form or sheet material and is of a width proportionate on the aforesaid scale, to the width of the over-lay material to be applied to the floor. In order to realize all of the advantages of the invention, this template also carries indicia indicative of the subdivisions of the scale to which it is made and orientation indicia which may conveniently be so spaced as to serve as scaling indicia as well. The under side of the template carries an adhesive of the type known as a repositioning adhesive by means of which the template may be removably adhered to the drawing of the floor area and repositioned thereon at will.
    Type: Grant
    Filed: September 6, 1985
    Date of Patent: April 21, 1987
    Inventor: Hafiz Arafat
  • Patent number: 4656755
    Abstract: A fitting is provided for locating and securing a channel-shaped carpet edging cap along the bottom of a wall at a predetermined height above a floor or carpet surface. The fitting comprises an angle section base member and a cap-supporting member adjustably mounted on the base member so that an upper edge of the cap-supporting member can be adjusted to the required height of the cap. In use, the cap is supported on the upper edge of the cap-supporting member in contact with the wall and is secured to the wall by staples which are applied through notches formed in the cap-supporting member.
    Type: Grant
    Filed: April 10, 1986
    Date of Patent: April 14, 1987
    Inventors: Donald A. Birnel, Kenneth G. Manson