US3473450A - Apparatus for installing flexible strip material in green concrete - Google Patents

Description

Get. 21, 1969 v, w KOCH 3,473,450

APPARATUS FOR INSTALLING FLEXIBLE STRIP MATERIAL IN GREEN CONCRETE Filed June 12, 1967 3 Sheets-Sheet l $2 FIG 2 3626 86 INVENTOR. VERGIL W. KOCH I) i "54M ATTORN'EYS Oct. 21, 1969 v. w. KOCH APPARATUS FOR INSTALLING FLEXIBLE STRIP MATERIAL IN GREEN CONCRETE Filed June 12, 1967 FIG 3 INVENTOR. VERGIL W. KOCH ATTORNEYS FBG....4

Get. 21, 1969 v. w. KOCH R APPARATUS FOR INS LING FLEXIBL MATERIAL GREEN CONCR .5

Filed June 1.2, 1967 3 Sheets-Sneet 3 INVENTOR. VERGIL W. KOCH w Ws'M ATTORNEYS nited States Patent 0 3,473,450 AZPPARATUS FOR INSTALLING FLEXIBLE STRIP MATERIAL TN GREEN CONCRETE Vergil W. Koch, 105 Hobart Ave., San Mateo, Calif. 94492 Filed June 12, 1967, Ser. No. 645,256 Int. Cl. E010 19/00, 23/00 US. Cl. 94-39 12 Claims ABSTRACT OF THE DISCLOSURE concrete with ease. When positioned at the proper depth L the jaws of the gripping beam are opened to release the strip material, after which the gripping beam is withdrawn upwardly.

This invention relates to an apparatus for installing in green concrete a flexible expansion joint strip material which forms a weakened plane joint when the concrete has cured.

In the construction of flat concrete slab-type structures such as roadways, aircraft runways, taxiways and parking areas, it has long been a problem to accommodate the contraction of the concrete after it has been poured and cured and also its subsequent expansion and contraction due to environmental conditions including ambient temperature changes. It has been found that expansion strips made from flexible material and installed transversely at various spaced apart intervals in the concrete slab will cause the cured concrete to crack beneath the strips and thus along predetermined lines below the slab surface. Thus, the strip material embedded in the slab allows the necessary expansion and contraction of the concrete at its surface and thereby prevents any surface cracking. Expansion joint strip material, such as polyvinylchloride which has been developed and used successfully, is generally narrow and thus quite flexible; and its height and thus the depth of its penetration into the concrete when installed may vary depending on the thickness of the concrete slab. In order to perform its function properly, this flexible strip must remain absolutely straight when installed with no bends, kinks or ripples in either the horizontal or vertical planes. Because of its inherent flexibility such strip material had a normal tendency to become distorted, bent or curved when forced into green concrete by procedures and apparatus heretofore devised.

A general object of the present invention is to provide an apparatus that will overcome the aforesaid problem and facilitate the installation of flexible expansion joint strip material into green concrete at the desired location and depth and without causing or allowing the material to wist, bend or distort in any way.

More specifically, an object of my invention is to provide an apparatus that grips a strip of flexible expansion joint material along its entire length, positions it above the concrete at the desired location, penetrates the green concrete with the strip material to form a depression, and then releases the material within the depression so that the strip of material remains in the concrete straight, free from curves or bends and with its upper edge flush or parallel with the concrete surface.

3,473,450 Patented Oct. 21, 1969 ice Yet another object of my invention is to provide an apparatus capable of installing expansion joint strips of various predetermined lengths on green concrete surfaces. My apparatus is easily adjustable to accommodate various types of concrete slab structures which require specific lengths of strip material, and the precision of installation is maintained even for the relatively long pieces of material.

Another object of my invention is to provide an apparatus for installing an expansion strip in green concrete that can be operated with precision by relatively unskilled labor and also an apparatus that is easy to service and maintain.

Still another object of my invention is to provide an apparatus of the aforesaid type which is particularly easy and convenient to load with a length of strip material before the apparatus is operated to install it.

The apparatus according to my invention which accomplishes the aforesaid objectives is characterized by an elongated gripping beam comprised of rigid portions that pivot together in a scissors-like action to hold the flexible strip material in a straight unbent position. With the strip material thus held firmly the rigid beam portions together form a knife-like edge that easily penetrates the green concrete when a downward force is applied. The rigid portions may be vibrated as a unit to increase their penetrating ability. The gripping beam is so shaped that it essentially positions itself and thus the strip material at the desired depth in the concrete, and when its proper position is reached it is easily actuated to release the strip material and withdraw from the concrete.

Other objects, advantages and features of my invention will become apparent from the following detailed description together with the accompanying drawings, in which:

FIG. 1 is a view in perspective showing an apparatus embodying the principles of the present invention;

FIG. 2 is a fragmentary view in side elevation and in section taken along the line 22 of FIG. 1 with portions broken away to conserve space;

FIG. 3 is an enlarged view in end elevation with portions broken away;

FIG. 4 is a further enlarged fragmentary view in elevation and in section taken along the line 44 of FIG. 2;

FIG. 5 is a view in end elevation showing my apparatus with the strip material gripping beam in its loading position;

FIG. 6 is a fragmentary view showing a portion of the frame in the extended position;

FIG. 7 is another fragmentary view in perspective showing an extension of the gripping beam;

FIGS. 8-12 are a series of enlarged, fragmentary views showing the operative steps of my apparatus for installing an expansion strip according to the present invention, wherein:

FIG. 8 shows the expansion strip initially inserted in the gripping beam;

FIG. 9 shows the gripping beam closed on the expanslon strlp;

FIG. 10 shows the gripping beam after being inserted in green concrete with the expansion strip;

FIG. 11 shows the gripping beam as it is being withdrawn from the green concrete, leaving the expansion strip embedded thereon; and

FIG. 12 shows the expansion in place after the gripping beam has been withdrawn.

Referring to the drawing, FIG. 1 shows an apparatus 20 embodying the principles of the present invention as it appears when in normal use for installing an expansion strip of flexible material in green concrete. The apparatus is particularly adaptable for installing a strip material 22, as shown typically in FIG. 12. The dimensions of such material can vary for different uses but generally it has a tapered cross section with its thicker portion at the upper end. The height of the material and thus the depth which it must penetrate the concrete is several times its greatest thickness and can vary depending on the thickness of the concrete slab that is to be formed. The strip material is usually made from a flexible elastomeric or plastic material such as polyvinylchloride and thus it is seen that with its tape-like configuration, it must be well supported in order to be installed in concrete withou bending or twisting in any manner. Aside from the fore going, it should be understood that the apparatus is not limited to use with only the strip material shown and the invention embodied therein is applicable to the handling of other elongated, flexible materials.

In broad terms, my apparatus comprises a rigid frame 24 which is long enough to extend across a section of green concrete 28 and is provided with first and second sets of wheels 26 and 27 which can be used alternately to move the apparatus into position over a recently poured concrete section. The first set of wheels 26 are fixed in position and adapted to ride on rails or forms on the opposite sides of a concrete section. The second set of wheels 27 are extendable rather than fixed so that the apparatus can be supported on a hardened surface other than rails if desired. The frame supports a rigid, elongated gripping beam 30 that also extends across and just above the concrete and which can be moved vertically downwardly to penetrate into it. This beam functions to receive and grip a precut length of flexible expansion joint material 22 which must be placed in the concrete before it solidifies in order to provide for a weakened expansion joint after the concrete cures. It provides a means for gripping the expansion strip material, for inserting it into the concrete and for releasing it when within the concrete so that the strip will remain at exactly the proper position and depth necessary to perform its function after the beam is withdrawn.

The apparatus is devised so that the manipulation of the gripping beam to provide the aforesaid functions as well as others may be accomplished by various suitable power means such as a hydraulic or pneumatic pressure source. Since the details of such a power system are conventional they will not be shown or described in detail except that particular actuator means and control valves are shown, the latter being arranged conveniently at a control console 32 at one end of the apparatus.

Describing now the apparatus in greater detail, the frame 24 comprises a pair of horizontal end beams 34 that are parallel and spaced apart a distance greater than the width of the concrete section being poured. On each end beam are mounted a pair of the fixed wheels 26 which are adapted to ride on rails 36 or the concrete forms that usually are provided on opposite sides of the slab or strip that is being constructed. The extendable wheels 27 are of the swivel type and each is supported at the extreme end of an end beam 34 on a jackscrew mounted in a cylinder 35 which is adjustable vertically by a hand crank 37 each cylinder being attached to the frame by a pair of bracket members 39.

Fixed to each of the end beams, as shown in FIG. 2, are two spaced apart upright frame members 38 and 40 which are connected by a cross member 42 at their upper ends. Journaled in each of the upright frame members 38 at opposite ends of the apparatus is a rotatable shaft member 44 having an inner end fixed to one side of a plate 46. Welded to the other side of each plate 46 and aligned with its shaft is an elongated box beam member 48 that fits slidably within a central sleeve member 50 having a rectangular cross section that receives the box beam members at both ends with a fairly snug but slidable clearance. As shown, the box beams extending from each upright frame member 38 fit well within the sleeve member so that the end beams 34 can be spread apart farther when necessary to increase the length of the apparatus and thereby enable it to install expansion strip material in wider slabs of concrete. Spaced on opposite sides of the sleeve 50 and parallel to it are similarly extendable support beams 52 and 54, each being comprised of a pair of slidably connected tubular sections that are fixed at one end to the end beam 34. These adjustable support beams not only strengthen and stabilize the frame 24, but they help to maintain the end beams parallel to each other as the apparatus 20 is moved from one location to another.

Fixed to the central sleeve 50 are a plurality of spaced apart linear actuators 56 each having a ram 58 that is connected to the gripping beam 30. Two of these actuators are used in the embodiment shown, but three or more could also be utilized if desired on larger machines. Adjacent to each actuator is a tubular member 60 that is also fixed at a right angle to the central sleeve at one end and is slidably connected with a guide member 62 which fits within the member 60 and is connected at its lower end to the gripping beam. Thus, the actuators provide a means for moving the gripping beam 30 vertically with respect to the horizontal central sleeve member 50 while also maintaining it parallel thereto. These actuators are preferably connected in parallel in a conventional manner and may be powered by any suitable hydraulic or pneumatic pressure system (not shown). They also are preferably controlled to operate in unison by means of a standard type valve 64 which may be mounted on the control console 32 forming the frame crosspiece 42 at one end of the apparatus.

The gripping beam 30 which is an important feature of my apparatus 20 provides a means for grasping a piece of flexible expansion strip material 22 along its entire length and retaining it as the actuators extend the beam 30 downwardly and force it into green concrete at the desired location. As shown in FIGS. 8 to 10, this beam comprises two elongated but rigid members 66 of similar cross section which are joined together by an axially extending, piano-type hinge 68. Each beam member 66 has a lower leg portion 70 having a depth that is somewhat longer in cross section than the crosssectional height of the expansion strip material 22. Extending at a right angle from the top edge of each lower leg portion and outwardly from the hinge axis is a flat intermediate portion 72, and extending upwardly from the outer edge of the intermediate portion is an upper wall portion 74. Fixed to the outside of each of these upper wall portions is a channel member 76 that provides a significant stiffening to the gripping beam 30 and helps to prevent any deflection that would detract from the precision with which the strip material must be installed. The hinge 68 is attached to both of the intermediate portions 72 so that a predetermined separation of the lower leg portions is maintained along this hinge axis, the amount of separation being somewhat greater than the width of the expansion material 22 at its thickest point. When the upper wall portions 74 which are substantially parallel to the lower leg portions are pushed apart as the beam members 66 pivot about the hinge axis, the lower leg portions 70 come together in a scissorslike action. Thus, if a flexible strip of expansion material is placed between the lower leg members it is gripped tightly between them when the upper wall portions 74 are spread apart. In their gripping position, the bottom edges of the lower leg portions come closer together and thus form a tapered wedge-like cross section which facilitates the penetration of the gripping beam 30 into green concrete.

The actuators 56 are connected to the gripping beam 30 at points substantially along its center line in a mannet that allows the beam to be extended or retracted and yet provide its normal scissors-like action. For each actuator a transverse plate 61 extending across the top of the gripping beam is fixed at one end to a pin 63 which is pivotally supported in a pair of bearing lugs 65 fixed to the supporting channel member 76 on one beam member 66. At its other end the plate 61 is provided with a series of slots 67. A metal pad 69 fixed to the side channel 76 of the other beam member 66 extends beneath the plate and supports a series of bolts 79 that extend upwardly through the slots. 67. Thus, as a limited movement of the gripping beam members 66 takes place during its scissors action, the plate can move relative to the bolts and yet takes the entire load of the gripping beam applied to the actuators, the ram of each of the latter being pin-connected to a stud 81 fixed to the center of a plate 61.

As shown in FIGS. 3 and 4, control of the scissorslike gripping action of the gripping beam 30 is accomplished by a plurality of double-acting, clamping actuators 77 that are spaced apart along it. Each of the latter actuators are pivotally connected at one end to the top of one upper wall with its ram 78 being connected to the opposite upper wall so that simple movement of the actuators will produce the desired pivoting of the beam members 66 about the hinge axis. Like the lifting actuators, these latter actuators may also be hydraulically or pneumatically powered and are controlled by a conventional valve 80 mounted on the control console 32.

Spaced apart on the gripping beam 30 and preferably adjacent to each scissors actuator 77 is a suitable vibrator device 82. A typical beam, as shown, may utilize three or more such vibrator units all of which are spaced at intervals on the beam and connected in parallel so as to be controllable by a suitable switch 84 on the control console. These vibrators produce a small amplitude vibration in a vertical plane and are turned on when the gripping beam is being inserted into and when it is being withdrawn from the green concrete. Various types of vibrators which are commercially available may be utilized and thus they will not be described in detail.

In order to load the gripping beam 30 with a strip of expansion material 22, it is possible to swing it upwardly from a position wherein the beam is aligned vertically beneath the central sleeve 50 to a position where it extends substantially horizontally outwardly from the sleeve (see FIG. 5). This approximate 90 of rotation is accomplished by a pair of actuators 86 located at opposite ends of the apparatus. Each of the latter actuators is pivotally connected to an upright frame member 40 and its ram 88 is connected by means of a link 90 to a crank arm 92 fixed to the rotatable shaft 44 that is journaled in the other upright frame member 38. Both of the actuators are again powered by a suitable hydraulic or pneumatic pressure source and are controlled by a single valve 94 which also is conveniently installed on the control console 32.

As mentioned previously, the frame 24 may be lengthened by spreading the side beams 34 apart when necessary in order to accommodate concrete slab structures such as roadways, runways and the like of varying widths. As shown in FIG. 6, the box beam members 48 can slide outwardly from the central sleeve 50 while still providing it with ample support. The telescoping support beams 52 and 54 can be extended in the same manner. When the frame is extended in this manner an auxiliary gripping beam section 300 can be added to the main gripping beam 30 as shown in FIG. 7. This additional section has the same configuration in cross section as the main gripping beam and comprises a pair of rigid, pivoted beam members 66:: which are connected by a piano-type hinge 680. Fixed within each of its channel portions 7612 along its upper edge is a connecter bar 96 that fits within the aligned channel portion of the main gripping beam 30. The auxiliary beam section thus attached can function effectively in the same manner as the main gripping beam.

The operation of my apparatus 20 may be reviewed briefly by particular reference to FIGS. 8-12 which illustrate somewhat diagrammatically the steps for installing a section of expansion joint strip material. In FIG. 8

the gripping beam is shown in the up position for loading a piece of strip material between the jaw-like lower leg portions 70 of the gripping beam 30. The beam 30 is moved to this horizontally oriented position by manipulation of the valve 94 to operate the actuators 86 which rotate the shafts 44 in the upright frame members 38 and thus the central sleeve 50. With the strip material properly inserted, the jaws of the gripping beam 30 are closed by manipulation of the valve to operate the scissors actuators 77 (see FIG. 9). Now, the valve 94 is again moved to operate the actuators and move the gripping beam 30 into its vertical position which is reached automatically with precision as the actuators return to their fully retracted position. The vertical inserting and lifting actuators 56 are now operated by manipulation of the valve 64 and as their actuator rams extend at the same rate, the closed gripping beam with the strip material 22 held firmly, moves downwardly to engage the surface of the green concrete (see FIG. 10). At this point the switch 84 may be placed in the on position to energize the vibrators 82. The gripping beam thus continues its downward travel and penetrates the concrete at a substantially uniform rate along its entire length.

When the gripping beam has penetrated to its proper depth its intermediate portions 72 are flush against the surface of the concrete. The valve 80 is now manipu lated to open the jaw-like lower portions 70 of the gripping beam which releases its clamping pressure. As shown in FIG. 11, with the vibrators still in operation, the valve 64 is now moved to the retract position, and the open gripping beam 30 is withdrawn from the concrete.

After the withdrawal of the gripping beam, the wet concrete will normally flow around and fill against the sides of the expansion joint strip material, which is straight without any curves or twists, as shown in FIG. 12. After the concrete has set, an upper portion 98 of the strip material 22 which is preferably attached to the main lower portions by a thin web, may be removed and replaced with a suitable filler such as asphalt. As the concrete cures and subsequently contracts it will crack directly beneath the installed expansion strip, but this will relieve internal stresses and prevent any surface cracking of the concrete slab even during substantial fluctuations in ambient temperatures.

To those skilled in the art to which this invention re lates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. Apparatus for installing an elongated flexible strip of material in green concrete comprising:

aframe;

a horizontal beam supported by said frame and having elongated movable jaw members for gripping and supporting a length of flexible material;

first actuator means on said beam for closing and opening said gripping jaws, said jaws forming, when closed, a rigid, wedge-shaped enclosure for the flexible material having a relatively narrow lower edge;

a second actuator means connected to said frame for moving said horizontal beam downwardly with sufficient force when said jaw members are closed to penetrate a section of green concrete and then upwardly into a retracted position; and

controllable power means independently connected to said first and second actuator means.

2. The apparatus as described in claim 1 wherein said movable jaws of said horizontal gripping beam are elongated planar members, and a hinge pivotally connecting said elongated members together along substantially their full length.

3. The apparatus as described in claim 1 wherein said elongated jaw members each have a lower leg portion, an intermediate portion extending outwardly from the upper edge of each said lower portion, and a hinge fixed to said intermediate portions and maintaining said lower leg portions at a spaced apart distance along their upper edges.

4. The apparatus as described in claim 1 wherein, said control means comprises a series of spaced apart hydraulic valves on a horizontal plate fixed to one of said upright frame members and forming a control console.

5. Apparatus for installing an elongated, flexible strip of material in green concrete comprising:

a frame including a pair of upright members and a cross beam with end shaft members rotatably supported in said upright members;

a horizontal lbeam connected to said cross beam and having elongated movable jaw portions for gripping a piece of flexible material along its sides;

first actuator means on said beam for closing and opening said gripping jaws;

a second actuator means connected to said frame and said cross beam for moving said horizontal beam downwardly with suflicient force to penetrate a section of green concrete and upwardly into a retracted position;

a third actuator means for rotating said cross beam in said upright frame members to thereby allow said gripping beam to be moved from its vertical position to a substantially horizontal position for loading; and

power means connected to said first, second and third actuator means.

6. The apparatus as described in claim 5 wherein said cross beam includes a central tubular member having a longitudinal flat-sided passage and box beam members fixed to said end shaft members and slidably connected with said central member.

7. The apparatus as described in claim 3 wherein said horizontal beam includes upper leg portions extending upwardly from the outer edges of said intermediate portions and a channel member fixed to the outside surface of each upper leg portion.

8. The apparatus as described in claim 7 wherein said lower, intermediate and upper portions of said elongated beam members are formed from an integral piece of sheet metal material.

9. The apparatus as described in claim 3 wherein said first actuator means comprises a plurality of linear actuators spaced apart longitudinally on said gripping beam with their ends pivotally connected to the upper ends of said elongated beam members.

10. The apparatus as described in claim 9 including a vibrator means connected to said gripping beam substantially adjacent to each said first linear actuator.

11. Apparatus for installing an elongated, flexible strip of material in green concrete comprising:

a frame including end beams, upright frame members on said end beams and spaced apart rail wheels fixed to each said end beam;

a horizontal gripping beam supported by said frame and having movable jaw portions for supporting a length of flexible material;

first actuator means on said beam for closing and opening said gripping jaws;

a second actuator means connected to said frame for moving said horizontal beam downwardly with sufficient force to penetrate a section of green concrete and upwardly into a retracted position;

transverse extensible support beam members interconnecting said end beams;

an extensible central beam connected to the upper ends of said upright frame members; and

an auxiliary gripping Ibeam extension connectable to one end of said gripping beam.

12. The apparatus as described in claim 11 including a plurality of vertically extentable wheels fixed to said frame.

References Cited UNITED STATES PATENTS 1,267,301 5/1918 Wieberg 94-51 1,804,337 5/1931 Heltzel 94-51 2,014,894 9/ 1935 Heltzel 9451 2,729,152 1/1956 Carnes 94-51 3,246,390 4/1966 Brown 94-51 X 3,270,636 9/ 1966 Worson 9451 3,286,607 11/1966 Middlestadt 94-51 3,335,647 8/ 1967 Thorp 94-51 NILE C. BYERS, JR., Primary Examiner US. Cl. X.R.

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