US3504500A

US3504500A - Pile jointing device

Info

Publication number: US3504500A
Application number: US728675A
Authority: US
Inventors: Jean Henry Winje Fristedt
Original assignee: Johnson Construction Co AB
Current assignee: Johnson Construction Co AB
Priority date: 1967-05-17
Filing date: 1968-05-13
Publication date: 1970-04-07
Anticipated expiration: 1987-04-07
Also published as: SE307108B; GB1216698A

Description

April 7, 1970 J. H. w. FRlsTL-:DT 3,504,500

PILE JOINTING DEVICE 2 Sheets-Sheet 1 Filed May 15, 1968 OOO.

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PILE JOINTING DEVICE Filed May 15, 1968 2 Sheets-Sheet 2 Fig.2

United States Patent O 3,504,500 PILE JOINTING DEVICE Jean Henry Winje Fristedt, Tyreso, Sweden, assigner to Johnson Construction Company AB., Stockholm, Sweden, a limited company of Sweden Filed May 13, 1968, Ser. No. 728,675 Claims priority, application Sweden, May 17, 1967, 6,905/ 67 Int. Cl. E02d 5/30, 5/52 U.S. Cl. 61-53 5 Claims ABSTRACT OF THE DISCLOSURE In pile driving work it is often necessary, depending on the driving depth, to compose each pile from a plurality of interconnected sections. For interconnecting such pile sections, various types of jointing devices have been proposed which consist of a body adapted to be mounted at one end of a pile section, and connecting means carried by this body. Such jointing devices generally are formed with flat abutment surfaces oriented in planes at right angles to the longitudinal axis of the respective jointing device and pile section and adapted, upon connecting together two jointing devices mounted on the respective pile sections, to butt against each other.

To enable jointing devices for the above-stated purpose to be regarded as satisfactory, the joint established by the same between any two pile sections must, in every respect, have a mechanical strength as high as that of the pile sections proper. Thus, the joints of a composite pile as obtained by means of the jointing devices must not involve any weakening of the pile. This requirement has been found to be best satised in joints which are accomplished thereby that, after moving the mating joint members of corresponding pile sections axially into abutment with each other, these sections are locked against relative axial displacement by causing mating connecting elements provided on the joint members to engage each other by a relative angular displacement of said members.

Heretofore, to enable such interconnection of separate pile sections, substantially two different alternative methods have been resorted to. According to one of such alternative solutions, jointing devices of identical designs were mounted at both ends of each pile section, and a separate intermediate member was `used for interconnecting two jointing devices disposed at adjacent ends of two pile sections, and the two jointing devices were relatively locked by this intermediate member. Such intermediate member, preferably, was in the form of an open-ended sleeve into which the two jointing devices were introduced with their end portions and were relatively locked by causing their connecting elements into engagement with mating connecting elements provided within the sleeve. According to the second alternative solution, jointing devices of different designs were mounted at the opposite ends of each pile section. In this case, one of the jointing devices was in the form of a female member or receptacle and the other was in the form of a male or plug member, the

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interconnection of these jointing devices being accomplished by moving these connecting elements or members into direct engagement with each other. In both cases, the interconnection was made by a relative rotation, or angular displacement, of the parts carrying the cooperating connecting elements. Both methods offer advantages as well as disadvantages relative to one another. While, according to the first alternative, the principal drawback resides in the necessity of using a separate intermediate member for interconnecting two jointing devices mounted at adjacent ends of two pile sections, respectively, according to the second alternative it is not feasible, as in the first case, to utilize that part of the top-most pile section of each pile which, after completely driving the pile, is to be removed from the latter; as a matter of fact, in the first case such surplus parts can be reused as the topmost parts of further piles.

The present invention has for its object to obviate the drawbacks involved in the two above-stated cases while retaining their respective advantages. The invention should be considered as a development of the wellknown type of pile jointing device comprising a body plate adapted to be secured to the end of a pile section and having a at face for abutting the flat face of a mating jointing device secured to an adjacent pile section, and a plurality of connecting elements adapted, upon relative angular displacement of the cooperating jointing devices, to be moved into engagement with the mating connecting elements of the adjacent body plate, thereby locking the jointing devices against axial displacement, and the mainly characterizing feature of the invention resides in that prong-like connecting elements are provided radially inward of the peripheral edge of the body plate and distributed uniformly on a circle concentrical with the common axis of the pile section and body plate, and in that the body plate is formed at each connecting prong with a recess for receiving a mating connecting prong provided on a corresponding identical jointing device.

The jointing device of the invention, in addition to the possibility of utilizing identical jointing devices at the two ends of a pile section without the necessity of using any separate intermediate member for the jointing of two pile sections, as is the case according to the first one of the two alternative methods referred to hereinbefore, has the additional advantage of enabling reduced manufacturing cost, If, as is preferred, the connecting prongs and the recesses are spaced inwardly of the peripheral edge of the body plate by an amount such as to leave outwardly of the prongs an exposed, circumferentially continuous abutment surface, then a further advantage will be obtained in that a tight butt joint will be formed outside the prongs whereby the latter will be protected against corrosive attacking. If desired, the tightness of such joint may be enhanced by coating the joint surfaces with asphalt or any suitable other sealing material.

The invention will now be described more in detail with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view, partly in section, of a jointing device according to one embodiment of the invention, by way of example;

FIG. 2 is a plan view of the jointing device depicted in FIG. l; and

FIG. 3 is a side elevation, partly in section, of a pile driving tip adapted to be connected to the jointing device shown in FIGS. 1 and 2.

The jointing device shown in FIGS. l and 2 comprises a body in the form of a hexagonal plate 1 having at its peripheral edge a skirt 2. welded `to the plate and depending in a direction at right angles to the plane of plate 1. This skirt 2 is adapted, when the jointing device is mounted on a pile section, to embrace peripherally the corresponding end portion thereof. The jointing device illustrated in the drawing, being adapted primarily for mounting n a concrete pile in conjunction with the casting thereof, further comprises, for anchoring the jointing device on the pile, a plurality of anchoring elements in the form of reinforcement bars 3 rigidly secured to the plate 1 and projecting perpendicularly from the plate 1 in the same direction as the skirt 2. The face of plate 1 opposite to the skirt 1 and reinforcement bars 3 constitutes a at abutment surface for a cooperating jointing device. Provided thereon are a plurality of axially protruding, pronglike connecting elements 4 arranged in a circular row at constant pitch and consisting of circumferentially extending lugs punched out from the plate material. Each Such lug 4 is formed at its free end with a detent 4a extending in substantially parallel relation to the abutment surface of plate 1, although its underside is inclined at a small angle relative to the main portion of plate 1 in such a way that its spacing from the underside of plate 1 is greatest at the free end of detent 4a, said spacing approximately centrally between the ends of detent 4a being equal to the thickness of plate 1. The detent 4a is further so formed that the distance between the abutment surface of plate 1 and the top surface of the detent 4a, being parallel to said abutment surface, is slightly less than the thickness of plate 1.

To enable two jointing devices of the kind described to be interconnected by engaging the detents 4a of the connecting prongs 4 of each such device beneath corresponding lugs -of the opposed jointing device, plate 1 is provided with punched-out apertures or recesses 5 directed circumferentially in the extension of the openings in the plate 1 left by the operation of punching out the olf-set connecting prongs 4. Upon interconnecting the two jointing devices, they are engaged with their prongs 4 into the openings S of the opposed jointing device, after which, by angularly displacing the jointing devices relative to each other, their detents 4a are moved in beneath one another. By this action, the abutment surfaces of the plates 1 of the two jointing devices will be wedged into surface contact with each other owing to the fact that the inclination of the bottom surfaces of the detents 4a will create an axially directed force component. After the two jointing devices having been interconnected in this way, they may be locked in their assembled condition by screwing in a locking screw 6 in a screw-threaded hole made in the plate 1 of each jointing device at a position behind one of the prongs 4 of the mating jointing device.

The jointing device thus described is extremely advantageous from a 'manufacturing point of view, since it can be made at lower cost than prior art jointing devices. The jointing device is manufactured by cutting a plate 1 into hexagonal shape, punching the openings 5 and holes for receiving the reinforcement bars 3, off-setting the connecting prongs 4, drilling and screw-threading the hole for the locking screw 6, inserting and upsetting the ends of the reinforcement bars 3 to secure them in their holes, and welding the skirt 2 to the plate edge. Further, to prevent concrete from penetrating into the openings formed in the plate 1, covering elements 7 are placed opposite these openings.

As seen in FIG. l, the skirt 2 is provided with a hole 8 for visually controlling the complete filling of the interior of the skirt with concrete upon casting a concrete pile.

FIG. 3 illustrates a pile driving tip generally designated by 9 and adapted, by means of a jointing device comprising a body plate 1 and connecting prongs 4 carried by this plate and of the design described hereinbefore, to be detachably connected to a pile section provided with a jointing device as that shown in FIGS. 1 and 2.

This driving tip comprises a substantially conical, cast body portion 10 and a steel insert member 11 inserted in an axially extending bore formed in the lower end thereof and locked in place by a screw 12.

The jointing device thus described, of course, is suspectible of various modifications without departing from the scope of the invention. Thus, for example, the connecting prongs 4 may be varied in number, shape and disposition. Among such modified designs, the following ones may be mentioned by way of example: (a) designs in which the plate 1 has a square or circular configuration rather than the hexagonal shape shown in the drawings, and (b) designs in which the connecting prongs 4 are disposed immediately adjacent the peripheral edge of plate 1, for instance at each corner of the plate. Further, for anchoring the jointing -unit to a pile, the reinforcement bars 3 may be replaced by other types of anchoring elements, particularly where the jointing device is intended for use on a pile made of a material other than concrete. Finally, the body plate 1, of course, may be manufactured in several different ways, such as by casting, for example.

What is claimed is:

1. In combination, a pile section, a pile jointing device comprising a body plate secured to the end of said pile section and having a flat face for abutting the iiat face of a mating jointing device secured to an adjacent pile section, and a plurality of prong-like connecting elements adapted, upon relative angular displacement of the cooperating jointing devices, to be moved into engagement with the mating connecting elements of an adjacent body plate thereby locking the jointing devices against axial displacement, the connecting elements being provided radially inward of the peripheral edge of the body plate and distributed uniformly on a circle concentric with the common axis of the pile section and the body plate, said connecting elements extending above and being spaced from the flat face of the plate, the body plate being formed at each connecting element With a recess extending in front of and under the associated connecting element for receiving a mating connecting element provided on a corresponding identical jointing device.

2. A pile jointing device according to claim 1 characterized in that the connecting elements and recesses are spaced inwardly of the peripheral edge'of the body plate by an amount such as to leave outwardly of the connecting elements an exposed, circumferentially continuous abutment surface.

3. A pile jointing device according to claim 1 characterized in that the connecting elements tit the recesses of the mating jointing device with a minimum of radial clearance, thereby preventing any radial displacement of the two jointing devices relative to each other.

4. A pile jointing device according to claim 1 characterized in that the connecting elements are formed from circumferentially directed lugs punched out from the body plate, and in that the recesses for receiving the connecting elements of the mating jointing device are constituted by punched-out apertures directed circumferentially in the extension of the lugs.

5. A pile jointing device according to claim 1 characterized in that the body plate is provided at its peripheral edge with a depending skirt for embracing the end portion of the associated pile and is anchored to the pile by means of elements embedded into the pile.

References Cited UNITED STATES PATENTS 7/196'2 Preissler et al. 287-103 X 9/1963 Severinsson 61-53 JACOB SHAPIRO, Primary Examiner