US2239872A - Apparatus for sinking forms for concrete piles - Google Patents

Description

April 29, 1941.

APPARATUS FOR SINKING FRMS FOR -CONCRETE PILES E. 1'. BEPLAT Filed March 25, 1939 ATTORNEYS Fatented pr. 29, 1941 iJNlTED STATES PATENT OFFICE APPARATUS FOR SINKING FORMS FOR CONCRETE PILES 6 Claims.

The present invention relates to pile driving, and more particularly to an improved apparatus for rapidly and effectively sinking tubular forms such as are used in the construction of concrete piles, although it is not limited to such use.

In the present method of sinking forms of this character, the form is driven into the earth by means of a Isuitable hammer until the forces oi friction acting inside and outside the form substantially retard its movement. 'I'he driving lis then stopped and the material within the form is blown `out by means of air under pressure from a hose lowered into the' form. By alternate driving and blowing in this manner, the form is iinally sunk to the desired depth.

The method described above has been found to be generally unsatisfactory in several respects. For one thing, it cannot be used economically v in driving formsof large diameter, because the cost of providing sufficient air to maintain the necessary pressure in such forms, for the effective removal of the excavated earth is excessive. Accordingly, it has been the customary practice to sink a plurality of forms of relatively small diameter rather than one or several forms of large diameter, although the latter is by far the better practice.

The principal objectof the present invention, accordingly, is to provide an improved apparatus for sinking forms for concrete piles, which is free from the defects of the prior art mentioned above, and by means of which forms of relatively large diameterI may be sunk economically and in a rapid and highly effective manner.

Another object of the invention is to provide an improved apparatus of the above character in which the earth within the boundary of the form may be excavated simultaneously with the driving of the form.

A further object of the invention is to provide an improved apparatus of the above character which is adaptable for use in sinking `piles of diierent diameter. l

In a preferred embodiment of the invention, a blowing head is provided which is adapted to be lowered within a. form, and which comprises a plurality of nozzles concentrically disposed about a discharge opening. Air under pressure is adapted to be directed from the nozzles against earth adjacent the periphery ofthe form, which is broken up and ldischarged together with the air, through the discharge opening in the head.

y The excavated material and air are then carried up the form through a conduit of relatively Vsmall diameter, in which the required pressure may be readily maintained with ordinary and economical quantities of air. Suitable means is provided in accordance with the invention for preventing the escape of air between the blowing head and the inner wall of the'form.

Additional objects will become apparent from the following detailed description taken in connection with the accompanying drawing, in which:

Fig. 1 is a view in vertical section of the lower Portion of an excavating device constructed in accordance with theinvention, and in an operative position within a form;

Fig. 2 is a view in vertical section illustrating the upper portion of the apparatus including the driving member;

Fig. 3 is a view in section taken along line 3 3 of Fig. l, looking in the direction of the arrows;

Fig. 4 is a view in section taken along line t-ll of Fig. 1 looking in the direction of the arrows; and

Fig. 5 is a view, partially in section, illustrating an alternative operative position of the device.

Referring to Fig. 1, a tubular form section is shown at ll), within the lower portion of which a blowing head ll has been lowered'. The blowing head il may be shaped to conform with the cross section of the form l0, and is provided with a centrally disposed discharge opening I2 through which excavated earth is adapted to be discharged. Formed within the head il is an annular passage i3 terminating at the lower extremity of the head il in a plurality of nozzles it of relatively small diameter, through which air under pressure is adapted to be directed against the ground adjacent the periphery of the form it.

At the upper portion of discharge opening l2 a circular recess i5 is provided, within which a discharge pipe It is adapted to be secured. A similar recess i5 is provided in the upper portion of the air passage i3 in which a second pipe ll of larger diameter than the discharge pipe i6 is adapted to be received. 'Ihe space between the discharge pipe i6 and the outer pipe Il provides an annular conduit Il through which air under pressure may be directed to the passage i3 in the blowing head Il for breaking up earth at the lower extremity of form section lll.

The discharge pipe IS may be welded `or otherwise secured to a second section of pipe I8, which in turn is Welded to the pipe I9 which directs the excavated earth to the discharge opening at the upper end of the form. The outer pipe I1 is closed oi by a suitable closure member 20 welded tov withstand high air pressure, which is provided with an aperture 2| into which an air supply pipe 22 is adapted to be fitted. The air supply pipe 22 may be held in position by means of a suitable clamp 23 bolted or otherwise secured to the pipe I9. 'Ihe length of the form may be increased by providing a suitable'coupling member 24 of a well known type, on which a second section 25 may be seated, and the length of the air supply pipe 22 and the discharge pipe I9 may be increased by adding sections in the conventional manner, using similar coupling members (not shown).

At the upper end of section 25 (Fig. 2) a coupling member 26 is provided on which a driving head is adapted to be seated. The coupling memfber 25 has a wide ange 21, in the under side of which a plurality of concentric grooves 2:3 are formed to accommodate forms of diierent diameter, section 25 being in one of the grooves 28. In the upper portion ci the coupling member 25, a circular recess 29 is formed in which the driving head 30 is adapted to be seated. In the upper portion of theI driving head 30 a circular plate 3| is secured to form a cylindrical chamber 32, within which an anvil 33 is adapted to be received. The anvil 33 may be provided with a plurality of recesses 34 in which the legs 35 of the usual driving hammer 36 are adapted to be positioned.

In the lower portion of the driving head1 30 a circular plate 31 is secured within which the apertures 38 and 39 are formed. Fitted within the aperture 38 is a short section of pipe 40 into which the upper extremity of the air supply pipe 22 is adapted to be slidably received. In order to provide an air-tight joint suitable packing 4| is provided,'which is held in place by means of glands 42 and 43, secured at the upper extremity of the pipe 22.

Fitted within the aperture 39 in plate 31 is a short section of pipe 44 of relatively large diameter, which is adapted to be slidably received within the discharge pipe I9. An air-tight joint is provided by means of the packing 45, which is held securely in place by the glands 45 and 41, secured at the lower extremity of the pipe section 44. It will be noted from the above that the distance between the driving head and the blowing head II may be varied over a slight range without breaking the connections to the air supply and the discharge pipe located at the upper portion of the forn'r 25.

A vertical member 48 is secured between the plate 3| and the plate 31 which forms an airtight enclosure into which air may be introduced from an air inlet 49 fitted in the wall of the driving head'30, by means of which air may be directed to the air supply pipe 22. A curved member 50 is secured to the vertical member 48 for directing the excavated earth from the discharge pipe 44 to an aperture 5Iv formed within the driving head 30. It will be evident that the curved memhowever, a space exists between it and the form ingly means is provided for blocking'o this air space during the blowing operations, as described below, in order that the air pressure within the form may be maintained as high as possible.

As shown in Fig. .1, a circular groove 52 is formed at the upper portion of the blowing head II, within which are provided a plurality of sectors 53 made of resilient material-such as, for example, rubber. Three su'ch sectors 53 are shown in Fig. 4, although any number might be used. Each of the sectors 53 is provided with a centrally disposed guide hole 54 within which a guide pin 55 is adapted to be received. The guide pins 55 may be secured to the outer pipe I1, as shown in Fig. 4, and where three sectors 53 are used their centers are preferably placed approximately 120 apart.

Above each of the pins 55 in the pipe I1 is a check valve 55 (Fig. 1) which is normally closed, but which is adapted to be opened whenever air under pressure is present in the passage between the discharge pipe I5 and the outer pipe I1. It will be evident that as soon as air under pressure is supplied to the device through thev inlet 49, the check valves 56 will be opened and a blast of air under pressure will be directed against each of the sectors 53, causing them to move out radially until they are in engagement with the inner wall of the form I0. It will be noted, however, that as the sectors 53 move outwardly, they tend to separate from each other so that a space exists between each of them, the centers of the spaces being approximately 120 apart, as shown in Fig. 4.

In ord-er to prevent the escape of air through these spaces, auxiliary sectors 51 (Fig. 4), also of resilient material, are provided. Each of these sectors 51 (Fig. 1) comprises a lower portion 53 of relatively small thickness, and an upper portion 59, whose width is such that it will lie ush with the two adjacent sectors 53 when its lower portion 58 is in contact with the rear sides of the adjacent sectors 53. Y

Each of the sectors 51 is also provided with an aperture 60 (Fig. l) within which a guide pin 6| is adapted to be received, the guide pins again being secured to the outer pipe I1 and disposed approximately 120 apart. In order that the auxiliary sectors 51 may move out radially on their guide pins simultaneously with the sectors 53, additional check valves 62 are provided in the pipe I1, which are normally closed, but which are adapted to be opened whenever air under' pressure is introduced into the apparatus. It will be evident that as soon as air is supplied to the apparatus, the sectors 53 and auxiliary sectors 51 will simultaneously move outwardly and radially'on their guide pins 55 and 5I, respectively, thus preventing the escape of air between the blowing head and the form III.

As shown in Fig. 3, the upper portions of the sectors 53 are held in place by means of suitable flange sectors 63 which may be bolted or otherwise secured to the outer pipe I1. The auxsection III through which air escapes. Accordiliary sectors 51 are likewise held in place by similar flange sectors .64 also secured to the outer pipe I1, so that the assembly is substantially airtight.

In operation the form II'I may be driven into the earth for a short distance so that the blowing head I rests upon the earths surface sul stantially as shown in Fig. 1. Air under pressure is then supplied to the inlet 49 and is directed from the nozzles I4 against the earth adjacent the lower periphery of the form III. The

charge opening I2, pipe I6, pipe I8, pipe I9, pipe 44 and out through aperture 5I. -It will be noted that the blowing head removes the earth within the boundary of the periphery of the form I so that the only frictional force retarding the movement of the form IIJ is that due to the earth adjacent its outside surface. Accordingly, the power required to drive the form in accordance with the present invention is substantially less than that required previously.

.Moreover, the driving head 30 may be driven during the blowing operation, thus enabling both the blowing and driving operations to be per-V formed simultaneously. In certain cases as, for example, where the soil is relatively soft, the weight of the head casting 30 and the anvil 33 will be suiiicient to sink the form I0 without the application of any external force.

The sinking operation may be further expedited by permitting the blowing head I i to lead the form I0 by a slight distance, as shown in Fig. 5. When this is done the ground is excavated to a substantial distance beneath the form l0, and only a relatively slight force is required to sink the form i0 to the required depth.

Before removing the blowing head l i from the form l0 after the driving operation has been completed, it is necessary that the sectors 53 and 51 be moved back into theirv normal positions in order to enable the device to be moved past the coupling member 24. For this purpose a plurality of vertical grooves 65 are formed in the surface of the sectors 53. These grooves 65 communicate with the space between the blowing device and the form at one end, but since they do not extend for the entire width of the sectors 53, air cannot` escape from the blowing nozzles I4 between the blowing head li and the form section l0. Similar grooves 66 are formed in the surface of the sectors 51 which, likewise, are blocked oi at their lower end but which communicate at theirupper ends with the space between the blowing device and the form.

When it is desired td move the sectors 53 and 51 to the normal disengaged position, air under pressure is introduced by means of the inlet 68 into the space between the form and the blowing device above the sectors 53 and 5l. This'air passes down through the grooves 85 and t6 and exerts sufElcient pressure to push the sectors 53 and 51 radially on their guide pins away from the inner wall of the form. Inasmuch as the check valves 56 and 62 close when the blowing operations are discontinued, a plurality of small vents 61 are provided in the blowing head il through which air trapped behind the sectors 53 and 51 may escape as the sectors 53 and 51 are moved away from the inner wall oi the form.

A plurality of blowing heads of different sizes may be provided for sinking pipes of various diameters up to the largest size desired. In all of the blowing heads, however, the diameter of the discharge pipe i6 will be maintained substantially the'same, and this diameter will be such that the pressure required for discharging excavated earth may be readily maintained without using excessive quantities of air. i

It will be evident from the foregoing that forms relatively large in diameter may be sunk rapidly, eii'ectively and economically in accordance with the present invention, and, since the blowing and driving operations maybe performed simultaneously, considerable saving in time is eiected. Moreover, the curved member 50 and the aperture 5| enable the direction of discharge of the excavated earth to be controlled, thus preventing possible damage to the clothing of passersby from contact with the material being discharged. This combination also eliminates the delays sometimes caused by the necessity for stopping the blowing operation in order i to let pedestrians pass without fear of having their. clothing soiled.

While a preferred embodiment of the invention has been described in detail above, the invention is not intended to be in any way limited thereby, but is susceptible of numerous changes of form and detail within the scope of the appended claims.

I claim:

1. In apparatus for sinking forms, the combination of a tubular member adapted to be lowered into a form, said tubular'` member having a passage therein for directing air against earth at the bottom of theform, and having a centrally disposed discharge opening therein, a cover member on the form having an air inlet vand a discharge outlet therein, a substantially airtight, telescoping conduit connected between said air passage and the air inlet, a second sub- `stantially airtight, telescoping conduit between said discharge opening and the discharge outlet, said conduits permitting relative movementv of said tubular member with respect to the cover member during the sinking of the form, an anvil on the cover member, and means for striking the anvil, wh-ereby earth within the form may be removed simultaneously with the driving thereof.

2. In apparatus for sinking forms, the combination of a tubular member adapted 'to be lowered into a form, said member having a plurality of nOzzles therein concentrically disposed about a centrally located discharge opening, means forming a passage in the tubular member for directing air to said nozzles, a conduit within the form for directing air under pressure to said passage in the tubular member, a second conduit within the form for directing excavatedl earth from the discharge opening, a plurality of resilient cylindrical sectors disposed about said air directing conduit and a plurality of check valves in said last-named conduit adapted to direct air under pressure therefrom against said sectors to move them into engagement with the form, whereby the escape of air between said tubular member and the form may. be prevented.

3. In apparatus for sinking forms, the combination of a tubular member adapted to be lowered into a form, said member having a plurality of nozzles therein concentrically disposed about a centrally locatedv discharge opening, means forming a passage in the tubular member for directing air to said nozzles, a conduit within the form for directing air under pressure to said passage in the tubular member, a second conduit within the form for directing excavated earth from the discharge opening, a plurality of movable resilient cylindrical sectors disposed about said air directing conduit, each of said sectors having an aperture therein, a plurality of spaced guide pins on said last-named conduit, adapted to be receivedA within said apertures, means on said air directing conduit for limiting the extent of movement of said sectors and forming therewith a substantially airtight assembly and a plurality of air check valves in said last-named conduit for directing air against said sectors to move them outwardly on the guide pins into engagement with the form whereby the escape of air between the tubular Amember and the formA may be prevented. A

i 4. In apparatus for sinking forms, the combination of a tubular .member adapted to be W- ered into a form, said member having a plurality of nozzles therein concentrically disposed about a centrally located discharge opening,

tubular member and the air inlet, the lower portion of said second conduit being concentric with means forming a passage in the tubular member for directing air to said nozzles, a conduit within the form vfor directing air under pressure to said passage in the tubular member, a second conduit within the form for directing excavated earth from the discharge opening, a plurality of movable resilient vcylindrical sectors disposed about said air directing conduit, means on said air directing conduit for limiting the extent of movement of said sectors and forming therewith a substantially airtight assembly, a plurality of check valves in said last named conduit for directing air therefrom against said sectors` to move them into engagement with the form, said sectors having a plurality of longitudinal recesses formed in the surfaces thereof, communicating at their upper. extremities with the space between the form and the tubular member,` and being less in length thanl the length of said sectors, an'air inlet for introducing air under pressure into the form above the tubular member to move the sectors away from the form, and a plurality of air vents for venting air trapped behind said sectors, whereby the sectors may be moved out of engagement with the form to facilitate the removal of the tubular member therefrom- 5. In apparatus for sinking forms, the combination of a tubular member adapted to be lowered into a form, said tubular member vbeing of lesser diameter than the diameter of the form, and having a plurality of nozzles therein concentrically disposed about a centrally located discharge opening, means forminga passage in the tubular member for directing air to said nozzles, a cover member on the form,- having an air Vand of greater diameter than said rst conduit,

a plurality of resilient sectors disposed about the lower portion of said secondY conduit, each having an aperture therein, a-plurality of guide pins on the lower portion of said second conduit, adapted to be received Within said apertures, means on the lower portion of said conduit for limiting the extent of movement of said-sectors and forming therewith a substantially airtight assembly and a plurality of air check valves in the lower portion of said second conduit for directing air therefrom against said sectors for moving them outwardly into engagement with the form, whereby the escape of air between the tubular member and the form may be prevented.A

6. In apparatus for sinking forms which includes a hollow member adapted to belowered into a form, said hollow member having passages therein for directing air againt earth at the bottom of the form, and having a centrally disposed discharge opening therein, the combination of a bearing member on the form, a driving head mounted on the bearing member, said driving head having an air inlet and a discharge outlet associated therewith, a substantially airtight, telescoping conduit connected to said air inlet and communicating with the passages in the hollow member, and a second substantially airtight, telescoping conduit connected between said discharge outlet and discharge opening, whereby the hollow member may move relatively to the driving head during the sinking of the form.

EMANUE'L T. BEPLAT.

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