United States Patent c191
`Ferstay
`
`[11] Patent Number:
`[45] Date of Patent:
`
`4,866,903
`Sep. 19, 1989
`
`[54] POSmONING DEVICE
`[76]
`Inventor: William G. Ferstay, 3923 Gilpin
`Street, Burnaby, British Columbia,
`. Canada, V5G 2H2
`[21] Appl. No.: 637,377
`Aug. 2, 1984
`[22] Filed:
`[51] Int. Cl.4 •••••••••••••••••••••••••••••••••••••••••••••••• E02D 5/74
`[52] U.S. CI ....................................... 52/677; 405/260;
`411/427
`[58] Field of Search .................. 52/677, 689; 405/259,
`405/260; 411/436, 427; 166/241
`References Cited
`U.S. PATENT DOCUMENTS
`2,591,631 4/1952 Stanitski .......................... 411/427 X
`3,020,955 2/1962 Tausch ............................ 166/241 X
`3,115,727 12/1963 Middendorf ...................... 52/733 X
`3,292,335 12/1966 Stober ................................... 52/677
`3,491,497 1/1970 Bauer .................................. 405/260
`3,721,094 3/1973 Elders et al ......................... 405/259
`3,971,177 7/1976 Endo ................................. 52/698 X
`4,027,572 6/1977 Burge .............................. 411/910 X
`4,042,023 8/1977 Fox ........................•............. 166/241
`l/1981 Chickini, Jr. et al ............... 405/260
`4,247,225
`
`[56]
`
`4,360,292 11/1982 Keeler et al .................... 405/260 X
`4,483,395 11/1984 Kramer et al ....................... 166/241
`
`FOREIGN PATENT DOCUMENTS
`743129 1/1956 United Kingdom .................. 52/677
`773769 5/1957 United Kingdom .................. 52/677
`778918 7/1957 United Kingdom .................. 52/677
`1342312 1/1974 United Kingdom .................. 52/677
`Primary Examiner-David A. Scherbel
`Assistant Examiner-Caroline D. Dennison
`Attorney, Agent, or Firm-Townsend and Townsend
`ABSTRACT
`[57]
`A centering device to locate and center a reinforcing
`thread bar in a hole formed in an excavation to receive
`a foundation of a building. The device has a body hav(cid:173)
`ing a band of appreciable thickness formed on its pe(cid:173)
`riphery. There is central opening. A thread is formed in
`the central opening to engage the thread of a reinforc(cid:173)
`ing thread bar. Sloping portions extend from the periph(cid:173)
`eral band, inwardly to the central opening. Openings
`allow concrete to pass by the device while the device is
`positioned in the hole.
`
`3 Claims, 1 Drawing Sheet
`
`Exhibit - 1020
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 1
`
`

`

`US. Patent
`
`Sep.19,1989
`
`4,866,903
`
`16
`
`6 2
`/
`
`--10
`
`Exhibit - 1020
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 2
`
`

`

`1
`
`POSmONING DEVICE
`
`4,866,903
`
`2
`to pass by the device while the device is positioned in
`the hole.
`
`FIELD OF THE INVENTION
`This invention relates to a reinforcement bar position-
`ing device.
`
`5
`
`DRAWINGS
`Aspects of the invention are illustrated, merely· by
`way of example, in the accompanying drawings in
`which:
`FIG. 1 is a front plan view of a device according to
`the present invention;
`FIG. 2 is an elevation of the device of FIG. l;
`FIG. 3 is a perspective view of the device according
`to the present invention; and
`FIG. 4 illustrates the location of a reinforcing bar
`using a device according to the present invention.
`
`DESCRIPTION OF THE PRIOR ART
`It is frequently necessary to reinforce the walls of an 10
`excavation site in the ground and nowadays such exca(cid:173)
`vation is frequently carried out by covering the earth
`and walls of the site with a cement layer. It is also well(cid:173)
`known to provide reinforced attachment points for this
`cement layer. This latter feature is desirable to add 15
`DESCRIPTION OF THE PREFERRED
`strength and support. Typically this is achieved by
`EMBODIMENTS
`drilling long, generally horizontal holes, into the sides
`The drawings show a centering device 2 to locate a
`of an excavation, placing a tube within the hole, (typi-
`cally of PVC or ABS) to aid in reinforcement bar posi-
`reinforcing thread bar 3 in a hole formed in an excava-
`tioning and cement flow, positioning steel reinforce- 20 tion to receive a building. A wall W of the excavation is
`ment bar in the tubes and finally injecting a cement mix
`shown in FIG. 4.
`The device 2 comprises a disk having a front face 4
`into the hole. The tube is removed and there remains a
`reinforced cement rod acting as an attachment point for
`and a back face 6 and a circumferential band 8. The disk
`the concrete surface of the foundation excavation.
`is of relatively great thickness at the band 8 and tapers
`Large numbers of these rods are usually required in one 25 outwardly to a central opening 10. The central opening
`excavation.
`10 is of the same diameter as the rebar 3, which extends
`The ultimate tensile strength of these rods, and thus
`completely through the disk. The disk is formed with an
`the strength of the retaining wall, is acquired when the
`internal thread in hole 10 to engage on the thread 11 on
`reinforcing bar (or rebar) is centered within the cement
`the rebar 3. There are semi-circular indents 12 in the
`rod This is because of the better surface adhesion be- 30 periphery of the disk. These recesses or indents 12 form
`arms 14, which support the rebar 3 away from the side
`tween the two parts acting to prevent slipping or pull-
`ing out of the rod. Although it is known to positioning
`of the hole. Holes 16 are provi~ed in the device 2. ~ese
`reinforcing bars in a mold and to ensure that these rein-
`holes 16 are clear holes extendmg through the device to
`forcing bars maintain a set distance between each other
`allow conc:ret~ to pass through.
`.
`the centering of reinforcing bars in foundation work is 35· The d~vtc~ ts 11:'ed as follows. Referrmg to FIG. ~ a
`~ol~ 18 IS drill~d m the earth w_all W of ~n excavat10
`
`typically carried out in various crude ways. For exam-
`ple it is common to tape small pieces of wood along the
`site m convent1on:31 _manner. A_s 1~ conventional tube ~.,
`of ABS or P': 9, 1~ mserted within the hole 18 to fac1h-
`length of the bar prior to inserting the bar into the hole.
`Such devices do not maintain the bar centered within
`tate rebar pos1~orung and to ease cement flow. A num-
`th h 1
`th 40 ber of the devices 2 are threaded on the rebar. The
`"all
`h
`t ·
`d • t
`e O e, espect Y w en cemen ts poure m O
`e
`spacing depends upon such factors as the weight and
`hole. Thus the re?ar ~ends to fall away ~rom the centre
`length of the rebar 3. The rebar 3, with the devices 2
`of t~e hole resulting m a cement r~d with sl1:bstandard
`attached, is then fully inserted into the bore hole 18. In
`tensile str~ngth and a corresponding, relatively low
`that bore hole the rebar 3 is centered as the outer diame-
`pullout reSIStance_. .
`.
`45 ter of the device 2 equals approximately the internal
`_In or~er to facilitate ~e gnp of the concrete o~ the
`diameter of the pipe 20.
`reinforcmg bar bars available under the term Dywi?ag
`Wet cement or grout is injected into the bore hole 20.
`thread bar have become well-known. Such a bar is a
`Because of the indents 12 and the holes 16 cement is free
`generally circular section bar with an extremely coarse
`to flow to the end of the bore hole with a minimum of
`thread formed on its exterior. The t~ead acts to im- 50 interference. When the concrete has been poured the
`prove the surface area of contact with the concrete.
`tube 20 is withdrawn and the cement left to harden.
`If the bore hole 18 is in badly broken or in rocky
`Nevertheles~ this does not remove the proble~ of
`proper loc~t1on of the bar and the _advantages_ available
`ground and insertion of a plastic tube 20 into the full
`from J?Ywtdag thread b~ are. still greatly tmproved
`length of the hole is not possible because of rock ob-
`according to the present mvention.
`55 structions, the rebar 3, prepared as above, can be in-
`SUMMARY OF THE INVENTION
`serted in position within the hole 18 within the aid of the
`plastic tubing 20. This is made possible because of the
`tapered faces of the device, which acts to guide the
`rebar around obstacles.
`The device according to the present invention may be
`made of a suitably robust plastic, for example nylon may
`be used.
`The particular advantage of the centering device of
`the present invention is cheapness combined with effi(cid:173)
`ciency. The device has a number of other desirable
`characteristics. For example the rebar 3 can be with(cid:173)
`drawn from the hole if redrilling the hole 18 is deemed
`necessary with the devices 2 attached. That is the
`
`The present invention provides a centering and locat(cid:173)
`ing device for thread bars. Accordingly, in its broadest
`aspect, the present invention is a centering device to 60
`locate and centre a reinforcing thread bar in a hole
`formed in an excavation to receive a foundation of a
`building, the device comprising a body having a band of
`appreciable thickness formed on its periphery; a central
`opening; a thread formed in the central opening to en- 65
`gage the thread of a reinforcing thread bar; sloping
`portions extending from the peripheral band, inwardly
`to the central opening; and openings to allow concrete
`
`0n
`
`Exhibit - 1020
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 3
`
`

`

`4,866,903
`
`3
`method of attachment by the thread within opening 10
`is secure and there is no reason why a device 2 would
`become displaced by removal from the hole 18.
`Furthermore the device is sturdy enough not to be
`distorted or otherwise affected by the heavy weight of 5
`the rebar but is yet small enough the provide substan(cid:173)
`tially unobstructive passage for cement flow and does
`not interfere with the strength of the bond between the
`reinforcing bar 3 and the concrete.
`I claim:
`1. -A centering device to locate and centre a reinforc(cid:173)
`ing thread bar in a hole formed in an excavation to
`receive a building foundation, the device comprising a
`generally circular, continuous body having a circumfer- 15
`ential band of appreciable axial thickness;
`a central opening;
`
`10
`
`4
`a thread formed in the opening to engage the thread
`of the reinforcing thread bar to permit longitudinal
`motion of said centering device along said bar only
`when rotation is applied;
`opposed sloping faces extending from the circumfer(cid:173)
`ential band, to the central opening and sloping so
`that the axial thickness increases inwardly;
`a plurality of openings passing axially through the
`sloping faces of the body to allow the passage of
`concrete through the device;
`substantially semi-circular recesses formed in the
`circumferential band to allow passage of concrete.
`l. A device as claimed in claim 1 in which there are
`four semi-circular recesses.
`3. A device as claimed in claim 1 in which there are
`four openings.
`
`* * * * *
`
`20
`
`25
`
`30
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`Exhibit - 1020
`NV5, Inc. v. Terracon Consultants, Inc.
`Page 4
`
`