US3769678A

US3769678A - Splicer for reinforcing bars

Info

Publication number: US3769678A
Application number: US00252018A
Authority: US
Inventors: R Marsden
Original assignee: STRICON PROD Ltd
Current assignee: STRICON PROD Ltd
Priority date: 1972-05-10
Filing date: 1972-05-10
Publication date: 1973-11-06
Anticipated expiration: 1990-11-06

Abstract

The invention provides a method and apparatus for connecting reinforcing bars such that tensile or compressive stress can be transmitted from one of the bars to the other of the bars. The apparatus includes an actuator, an anvil and a movable jaw connected to the actuator for movement towards the anvil. The anvil and movable jaw are shaped to fit snugly about the sleeve so that when the actuator applies a force, the sleeve is deformed between the movable jaw and the anvil.

Description

1 1 3,769,678 Nov, 6, 1973 United States Patent. [1 1 Marsden 9/1929 O'Donnell...

29/517 29/447 Gutmann..............................

[73] Assignee: Stricon Products Limited, Primary Examiner-Thomas H. Eager Mississauga, Ontario, Canada Attorney-David M. Rogers et al. May 10, 1972 [22] Filed:

[57] ABSTRACT The invention provides a method and apparatus for connecting reinforcing bars such that tensile or com- [21] Appl. No.: 252,018

pressive stress can be transmitted from one of the bars to the other of the bars. The apparatus includes an actuator, an anvil and a movable jaw connected to the actuator for movement towards the anvil. The anvil and movable jaw are shaped to fit snugly about the sleeve 72 3 w m 45 5 W9 2 0. O 5 B 2 5 B5/ 11 a 9 w 052 2 NW a 7 B 0 Pm 0 3 a BM m 0. U u U n h -m. c r n ma n e U .S L cm C l s cm .w U .mF N N 5 55 [56] References Cited so that when the actuator applies a force, the sleeve is UNITED STATES PATENTS deformed between the movable jaw and the anvil,

930,863 8/1909 Kearney.......... 29/447 6 Claims, 7 Drawing:Figures w '1 i z any;

PAIENIEDlmv 6 I975 SHEET 1 CF 4 PATENTEMnv 6 m5 sum u CF 4 w OE @9 www v wwm OK @9 WE www.mmawt Ow? Nb V9 @ON VON mm? Om? wwe SPLICER FOR REINFORCING BARS This invention relates to a splicer for connecting two reinforcing bars in end-to-end alignment, and more particularly to a splicer which when coupled to two reinforcing bars is capable of transmitting compressive and tensile stresses from one of the bars to the other of the bars.

In buildings of reinforced concrete, a large quantity of heavy reinforcing bar is used to make columns in the building. The columns are linked by floors to form a shell, and then fascia panels or the like are mounted on the floor and supported by the columns.

Two types of reinforcing bar splicers are available commercially for attaching adjacent reinforcing bars in end-to-end alignment. A first of the types is used in compressive loading situations and a second type is used where tensile stresses are anticipated. One splicer of the compressive type includes a sleeve having a generally C-shaped cross-section. A construction worker first slips the sleeve over an end of a lower one of the bars and holds it in that position while an end of a second reinforcing bar is entered downwardly into the sleeve to abut against the lower bar. The longitudinal edges of the sleeve diverge and the construction worker drives a tapered locking member into engagement with these edges to draw the edges together in wedge fashion about the reinforcing bars. This type of splicer requires considerable dexterity on the part of the construction worker, particularly when he is supported only on steel work.

Another splicer used in compressive loading situations consists of a sleeve portion having longitudinal edges defining a gap and a pair of flanges extending radially one from each edge. A pair of projections also extend radially from the edges below the flanges and bolts pass through the flanges and projections. The projections can be drawn toward one another by tightening a bolt in the projections to draw a part of the sleeve portion tightly about an end portion of a lower one of the bars. A second bar is then slipped downwardly into the sleeve portion and the bolts and the flanges tightened to draw the sleeve portion tightly about the second reinforcing bar. While this type of splicer is an improvement over the first type, it nevertheless suffers from the same disadvantage in that neither of these splicers are capable of transmitting substantial tensile stresses from one reinforcing bar to an adjacent reinforcing bar. Consequently, the use of these splicers is limited to structures where only compressive forces are anticipated.

Splicers for use in tensile loading situations include a splicer consisting of a specially machined sleeve placed about ends of adjacent reinforcing bars and into which liquid metal is poured. The metal is melted by the well known thermit process and on solidification the metal and sleeve are engaged tightly about the bars for transmitting tensile stresses. This process also has some disadvantages in that visual indications of the weld are used to determine whether or not the joint is successful. It is well known that a visual inspection of a weld can be misleading in that the weld may not be as strong as it would appear.

In one of its aspects, the present invention provides a method of connecting reinforcing bars such that tensile or compressive stress can be transmitted from one of the bars to the other of the bars. The method includes the steps of placing a sleeve having an internal diameter substantially equal to the external diameter of the bars over an end of one of the bars and then entering the end of another bar into the sleeve; and applying a tool to the sleeve to deform the sleeve radially so that the deformation causes the sleeve to grip the ends of the bars with sufficient force that tensile stresses can be transmitted through the sleeve from one bar to the other bar.

In another aspect of the present invention, a tool is provided for applying radial stresses to a sleeve for deforming the sleeve radially inwards about reinforcing bar ends to lock the sleeve to the reinforcing bars. The tool consists of an actuator; an anvil; a movable jaw connected to the actuator formovement towards the anvil, the anvil and movable jaw being shaped to fit snugly about the sleeve so that when the actuator applies a force, the sleeve is deformed between the movable jaw and the anvil.

These and other aspects of the invention will be better understood with reference to the drawings, in which;

FIG. 1 is a perspective view of a tool according to the invention;

FIG. 2 is a perspective view of a sleeve which has been applied to a pair of adjacent reinforcing bars to the tool;

FIG. 3 is a partially sectioned view of the tool looking from above FIG. 1;

FIG. 4 is a perspective view of a movable jaw used in the tool;

FIG. 5 is a perspective view of the tool mounted on a support for coupling the tool to a lower one of a pair of adjacent reinforcing bars;

FIG. 6 is a perspective view of a portion of the tool; and

FIG. 7 is a view similar to FIG. 3 of a further embodiment of the tool.

Reference is first made to FIGS. 1 and 2 with particular reference to FIG. I. A tool 10 consists of an actuator l2 operable to impart reciprocating movement to a movable jaw 14 for engagement with a sleeve 16 to drive the sleeve against a removable anvil 18. The jaw 14 and anvil 18 include respective dies 20, 22 having complementary shapes for imparting

local deformations

24, 26 at respective ends of the sleeve 16 to lock

end portions

28, 30 of reinforcing

bars

32, 34 in heated sleeve 16.

' Reference is now made to FIGS. 1 and 3 to describe. a typical construction of the tool 10. Four relatively

heavy rods

36, 38, 40 and 42 extend longitudinally from an end plate 44 to a removable end plate 46 forming part of anvil 18.

Rod 36 which is typical of all four rods, will now be described. The rod consists of a first end portion 50, an intermediate portion 52 and a second end portion 54. The

end portions

50, 54 are of similar diameter and the intermediate portion 52 defines a shoulder for abutting against an intermediate plate 56 through which respective first end portions of the

rods

36, 38, 40 and 42 pass. Returning to rod 36, the distal end of portion 50 is threaded to receive a nut 48 so that a tubular barrel 58 of the actuator 12 can be subject to a compressive stress by tightening the nuts 48 thereby applying a tensile stress to the first end portions of the respective rods.

The movable jaw 14 includes a reinforced support 59 which is slidably mounted on the intermediate portions of the rods. The die 20 is attached by a pair of bolts 60 (one of which is shown) passing through respective bosses 62 on the die. The shape of the die is better shown in FIG. 4 and will be described in more detail with reference to this figure.

Actuator 12 includes a piston 63 slidably mounted within the barrel 58 and including a plunger 64 which is slidably mounted within intermediate plate 56 and has a portion of reduced diameter 66 threadably engaged in a boss 68 on the back of support 59. An enlarged intermediate portion 70 of plunger 64 is sealed by O-rings 72 set in suitable grooves within intermediate plate 56. The plunger 64 also includes a stub 74 which extends towards plate 44 and terminates in a threaded portion 76.

The piston 63 consists of first, second and

third discs

78, 80, and 82 mounted snugly on the stub 74. Third disc 82 is adapted to locate about the intermediate portion 70 of the stub and includes an O-ring seal 84 between an end of the stub portion 70 and the disc 82. Respective O-

rings

86, 88 are located in grooves formed respectively between

discs

78, 80 and 80, 82. Further O-

rings

90, 92 are provided at respective ends of barrel 58 to seal the barrel to the end plate 44 and intermediate plate 56. Respective sides of the piston 63 define ends of first and

second chambers

94, 96 which (as seen in FIG. 3) are sealed by combinations of the O-rings previously described.

Chamber 94 is fed from a high pressure hose 98 carrying oil into the chamber for moving the piston longitudinally towards the removable end plate 46 and chamber 96 is connected by a hose 100 to the same hydraulic supply as the hose 98 with suitable valving as will be described. Consequently, when oil is fed through hose 98, oil leaves chamber 96 through the hose 100 and conversely on returning the piston to the FIG. 3 position oil is fed into the hose 100 and returned through hose 98.

When pressurized oil is fed through hose 98 into the first chamber 94, the piston 63 is forced axially towards the removable end plate 46. As a result, the movable jaw 14 is driven along the

rods

36, 38, 40 and 42 and the die 20 moves towards the die 22 for gripping a sleeve 102 shown in FIG. 3. The effect of this movement on the sleeve 102 will be more fully described with reference to FIG. 2. After applying a force to the sleeve 102, the pressurized oil is fed through hose 100 to the second chamber 96 to reverse the travel of the piston 63 so that the piston is then returned to the FIG. 3 position. Because the plunger portion 66 is threadably engaged in support boss 68, movement of the piston 63 towards its FIG. 3 position results in drawing the movable jaw 14 away from the sleeve 102. Consequently the actuator 12 can be used to move the jaw 14 from a withdrawn position (FIG. 3) to a clamping position in which the jaw 14 and anvil grip the sleeve 16 (FIG. 2) and then back to the withdrawn position.

The end plate 46 is retained on the

rods

36, 38, 40 and 42 by respective nuts 104 which are locked against shoulders formed at respective ends of second end portions of the

rods

36, 38, 40 and 42. The plate 46 can however, be removed relatively easily for replacing die 22. As seen in FIG. 1, the plate 46 includes a pair of

transverse recesses

106, 108 associated with

rods

36, 38 and a pair of generally L-shaped recesses 110 (one of which is shown) associated with

respective rods

40, 42. Plate 46 can be removed by first moving the plate in a direction away from

rods

36, 38 and towards

rods

40, 42 until a point is reached at which the

rods

36, 38 are outside the confines of the plate 46 and the

rods

40, 42 are in respective upright portions of the recesses 110. These aligned upright portions are proportioned to allow the nuts associated with

rods

40, 42 to pass through these portions so that the plate may be moved axially away from the rods. Proper alignment of the plate 46 on the rods is ensured by respective interlock ing faces 112, 114 and 116, 118 on the dies 20, 22.

The die 20 is shown in detail in FIG. 4. This die is typical in shape of both dies 20, 22 but for the form of interlocking faces 112, 114 and 116, 118 which of course are of necessity complementary. The curved die face consists of three-raised ribs 120 bordered by lands 122. In operation, it will be apparent from a comparison of FIGS. 2 and 4 that the ribs 120 create the

deformations

24, 26 previously described in the sleeve 16. As a result, the inner surface of the sleeve 16 is also deformed into close proximity with the raised ribs of the reinforcing

bar portions

28, 30 so that sleeve 16 is locked to the reinforcing bars for transmitting tensile stresses from one reinforcing bar to the other reinforcing bar.

Reference is now made to FIG. 5 to describe a support 124 by which the tool 10 can be attached to a lower reinforcing bar 126 for deforming a sleeve 128 about an upper portion of the bar 126 and about a lower end portion of an upper reinforcing bar 130.

The support 124 consists of a main member 132 defining a V-shaped jaw 134 at one of its ends for engaging the reinforcing bar 126 with the main member 132 extending substantially at right angles to the reinforcing bar 126. The main member defines a rectangular opening in which a tongue 133 is slidably engaged to permit limited movement. of the remainder of the support 124 relative to the main member 132 for reasons which will be explained. Tongue 133 is dependent from a cylindrical portion 136 which extends substantially parallel to the reinforcing bar 126 and houses an actuator 138 operable by pressurized oil entering through a high pressure hose 140.

The V-shaped jaw 134 combines with a movable jaw 142 which also has a V-shape and which is pivotally mounted on the main member 132 for movement about an axis defined by pivot pin 144. A further actuator 146 is pivotally connected both to the jaw 142 and to lugs 148 provided on the main member 132. The actuator 146 is double acting and is coupled to a pressurized oil supply by a pair of

hoses

150, 152.

The upper end of the actuator 138 is better shown in FIG. 6. An annular recess 154 is formed in the distal end of the actuator for engagement by a locking pin 156 adapted to engage in tangential openings 158 in a boss 160 on the underside of the barrel 58. The upper end of the actuator is a location fit in an opening 162 in the boss so that with the actuator locked in place by the pin 156, the tool 10 is located and supported above the bar 126 with the dies 20, 22 about the axis of the bar 126.

Any suitable hydraulic control system can be coupled to the tool and support for controlling the various movements which are to be described.

In use, the support with or without the tool is first attached to bar 126 with the actuator 138 in a withdrawn position so that the tool is in a lowermost position. If

the tool is included, the anvil 18 is first removed to simplify positioning the tool relative to the bar 126. Pressure is then applied through hoses 150 to actuator 146 so that the movable jaw 142 in combination with the jaw 134 grips the bar 126. The support 124 is preferably positioned such that the tool is adjusted by upward movement into the required position. Preparation is completed by adding anvil 18 to the

rods

36, 38, 40 and 42. With the support and tool in the proper position, the bar 126 will project beyond the

jaws

20,22 by a predetermined amount which the operator can check. Sleeve 128 is then heated to a predetermined temperature and dropped over the bar 126 until it rests on the main member 132 of the support 124, and then the upper reinforcing bar 130 is dropped into the sleeve 128 until it abuts against the upper end of the bar 126. This abutment can be inspected through a central opening 164 in the sleeve 128. Pressurized oil is then fed to hose 98 so that the movable jaw 14 closes the dies and 22 to apply compressive forces to the sleeve 128 thereby deforming the sleeve and creating the deformations 24 shown in FIG. 2. The sliding link consisting of the main member 132 and the tongue 133 permits the tool to move away from the bar 126 driven by the movement of jaw 14 until the anvil 18 provides a reactive force equal to the force applied by the jaw 14 driven by actuator 12.

After creating deformations corresponding to deformations 24 shown in FIG. 2, the oil supply to hose 98 is transferred to hose 100 so that oil is then pumped to chamber 96 to return the movable jaw to the withdrawn position. Oil from chamber 94 then escapes through hose 98.

Next the actuator 138 is supplied with oil to elevate the tool 10 to a position relative to the sleeve 128 for creating deformations corresponding to deformations 26 (FIG. 2). The die clamping procedure is then repeated before stressing actuator 138 to a withdrawn position. The anvil 18 is then removed as previously described and actuator 146 is withdrawn to release the support 124 from the rod 126.

It will be appreciated that the tool can be supported in many ways. For instance in splicing horizontal bars, if a vertical bar is available, another boss 160 can be provided on barrel 58 at a position 180 from the hose 100. When supported at this boss the tool would be in the FIG. 1 position.

Another alternate is to coupled the tool to a suitable trolley or the like which can be wheeled around a floor and used to support the tool when splicing bars. The trolley would include a device equivalent to actuator 138 (FIG. 5) for providing vertical adjustment of the tool.

Reference is now made to FIG. 7 which shows an alternative embodiment of the tool. The layout of this embodiment is similar to that of tool 10 and consists of an actuator 166 coupled to a movable jaw 168 which combines with a complementary anvil 170 to deform a sleeve about adjacent end portions of abutting reinforcing bars.

The actuator 166 consists of an end plate 172 intermediate plate 174, barrel 176 and six cap bolts 178 which pass through plate 172 and are threadably engaged in plate 174 to applya compressive stress to the barrel 176. Respective annular recesses in the plates 172, 174 receive ends of the barrel and seals 180, 182 are located in the plates to seal respective chambers 186, 188 at either side of a piston 190. A further seal 192 in the piston rides on the inner wall of the barrel 176 to limit seepage from one chamber to the other chamber. These chambers 186, 188 are connected by respective passages 194, 196 to parts where hoses can be attached.

Piston 190 is coupled by a large screw 198 to an end of a cylindrical and axially extending plunger 200. This plunger moves with the piston and extends through intermediate plate 174 guided by a journal bearing 202 and sealed by a pair of

seals

204, 206. Seal 204 is retained in a groove in plate 174 by a ring 208 which is attached by screws 210 to plate 174 and seal 206 is engaged in a groove in the ring 208.

A forward end of plunger 200 is spherical and is engaged in a complementary seating element 210 within the movable jaw 168 to provide for small misalignment. The element 210 rests against the back of a die 212 and is contained within a die support 214 by a pair of half rings 216 attached by bolts 218 to the support 214. These half rings have inwardly extending radial lips 220 engaged loosely in an annular recess 222 so that when the actuator 166 is used to return the movable jaw 168 to the withdrawn position, the lip 220 combines with the plunger 200 so that the jaw moves with the plunger.

Movable jaw 214 is slidably mounted on four long bolts 224 which extend through anvil 170 and are threadably engaged in intermediate plate 174. The anvil includes a pair of downwardly elongated openings associated with the The sleeves previously described have a length and cross-section suitable for gripping the reinforcing bars and for transmitting tensile and compressive stresses equivalent to the designed loading of the bars. In such cases the ends of the bars need not be dressed square because the compressive stresses are transmitted through the sleeve. However, where the loading is to be primarily compressive with minor or no tensile loading anticipated, the sleeves can have relatively thin walls sufficient only to align the reinforcing bars. In such cases heating may prove unnecessary although it will be necessary to dress the abutting ends of the bars for face-to-face engagement.

In a typical installation on number 18 reinforcing bars for tensile stresses, a 9 inch sleeve was used which was 3.625 inches outside diameter with a wall of 0.4375 inches. The sleeve was of seamless tubing in the C 1018 range and the temperation of the sleeve at compression was between 1600" and l850 fahrenheit. The tool had a piston diameter of 5.25 inches and a pressure of 10,000 p.s.i. was used to give a force of approximately tons.

I claim:

1. Apparatus for applying radial stresses to a sleeve to deform the sleeve radially inwards about aligned reinforcing bars to lock the sleeve to both reinforcing bars, the apparatus comprising a tool having an actuator; an anvil fixedly coupled to the actuator; a movable jaw connected to the actuator for movement towards and away from the anvil, the anvil and movable jaw being shaped to fit snugly about the sleeve so that when the actuator moves the jaw towards the sleeve, the jaw and anvil combine to deform the sleeve radially inwards between the movable jaw and the anvil and into tight engagement with the reinforcing bars.

2. Apparatus as claimed in claim 1 and further comprising a support adapted to be coupled to a first of the reinforcing bars and in which the tool and the support define means for releasably coupling the tool to the support.

3. Apparatus as claimed in claim 2 in which the tool includes means providing adjustment of the tool in a direction perpendicular to the axes of the reinforcing bars whereby the anvil is moved into engagement with the sleeve upon moving the jaw into engagement with the sleeve so that the anvil then absorbs a reactive force equal to the force applied by the jaw.

4. Apparatus as claimed in claim 2 in which the tool further includes means providing adjustment of the tool in a direction parallel to the said axes whereby the tool can be adjusted for deforming the sleeve at different locations along the length of the sleeve.

5. A tool for applying radial stresses to a sleeve to deform the sleeve radially inwards about aligned reinforc ing bars to lock the sleeve to both reinforcing bars, the tool comprising: an actuator; a plurality of guide rods fixedly coupled to the actuator and extending longitudinally from the actuator; an anvil relcasably coupled to distal ends of the guide rods such that the anvil can be removed only by first moving the anvil transversely; a movable jaw slidably mounted on the guide rods for reciprocal movement longitudinally between a withdrawn position in which the jaw is remote from the anvil and an outer position in which the jaw is adjacent the anvil; the jaw and anvil defining a pair of dies having complementary shapes such that upon energizing the actuator to move the jaw towards said outer position, the dies combine to deform the sleeve radially inwards into tight engagement with the reinforcing bars. 6. A tool as claimed in claim 5 in which the actuator is hydraulically operated.

Claims

5. A tool for applying radial stresses to a sleeve to deform the sleeve radially inwards about aligned reinforcing bars to lock the sleeve to both reinforcing bars, the tool comprising: an actuator; a plurality of guide rods fixedly coupled to the actuator and extending longitudinally from the actuator; an anvil releasably coupled to distal ends of the guide rods such that the anvil can be removed only by first moving the anvil transversely; a movable jaw slidably mounted on the guide rods for reciprocal movement longitudinally between a withdrawn position in which the jaw is remote from the anvil and an outer position in which the jaw is adjacent the anvil; the jaw and anvil defining a pair of dies having complementary shapes such that upon energizing the actuator to move the jaw towards said outer position, the dies combine to deform the sleeve radially inwards into tight engagement with the reinforcing bars.

6. A tool as claimed in claim 5 in which the actuator is hydraulically operated.