US1542590A - Forming cast-in-place piles - Google Patents

Description

June 16,-1925.

' J. H. THORNLEY FORMING CAST IN PL'ACE FILES 2 Sheets-Sheet 1 Filed March 6, 1923 avwewco'c June 16, 1925. 1,542,590

J. H. THORNLEY FORMING CAST IN PLACE FILES Filed March 6, 1923 2 Sheets-Sheet 2 Patented June 16,- 1925.

PATENT i ms.

JosErn nann THORNLEY, or new YORK, N. Y.

i FORMING CAST-IN-PLACE FILES.

Application filed liarch 6, 1923. Serial No. 623,097.

To all whom it may concern.

Be it known that I, JosErH HARRY THORN- LEY, a citizen of the United States, and a resident of the city of New York, county of- Kings, and State of New York, have invented new and useful Improvements in Forming Cast-In-Place Piles, of which the following is a specification.

My invention apparatus for driving cast-in-place concrete piles. It has for its object the providing of an improved means for the withdrawing of the form surrounding the formed concrete pile after the concrete has been deposited. It has been found that if the casing is withdrawn through means located on the frame, the reaction pressure from the withdrawal will tend to force the frame into the ground. Inasmuch as the piles are frequently placed in marshy ground this has been a serious defect in the past methods of placing piles and withdrawlng the forms. On the other hand, I have found that the best results are not'obtained by placing the reaction pressure entirely upon the concrete pile alread formed as in that case the latter has a ten ency to mushroom out at its base as the form is withdrawn, more concrete being forced downward than is needed to fill in the space left by the withdrawal of the form. My

invention relates to an improved method of withdrawing the form and apparatus for doing the same which will so divide the reaction pressure between the concrete pile and the ground surrounding the frame that only -enough concrete mixture will be forced downward as the form is withdrawn to compensate for the vacancies caused by such withdrawal. Great advantages are derived from the use of my dnvenpresent ti'on, particularly in that a pile will be formed of uniform cross-section throughout, that the vacant spaces left by the wlthdrawal of the form will be properly filled and there will be no gaps, nor will the concrete in the pile mushroom. Another advantage of the invention will be the avoiding of the uncertainty as to the final height of the concrete pile. If the concrete should mushroom to a large extent under the pressure ofv the rammer, the pile will necessarily be shortened, but in my invention the rammer forces the concretedownward only sufficiently to fill the vacancies and therefore the height of.

the concrete pile can be accurately deterrelates to improvements in mined by the amount of concrete mixture placed under the rammer before the withdrawal of the form takes place. The use of the invention also avoids the danger of arching and amming of the concrete pile by the placing of excessive pressure on it in the course of the withdrawal of the form.

I secure the foregoing advantages by means of the novel devices hereinafter shown and described. In the accompanying description I disclose my method and apparatus as shown in their preferred forms. It is understood, however, that my invention is not to be limited to the forms shown but is to include the various mechanical methods and means whereby the pressure reaction from the withdrawal of the form can be apportioned between the concrete pile and the surface of the ground.

In the accompanying drawings,

Fig. 1 is a side elevation of an apparatus embodying my invention; Fig. 2 is a front elevation of the same. Bothpf these figures show the form surrounding the concrete pile, partly in section. The form is partly withdrawn. Fig. 2 is a plan view of the top of the frame structure shown in Figs. 1 and 2. It serves to illustrate the relative arrangement of pulleys and blocks supported at the upper end of the frame. Figs. 1 and 2 likewise show the preferred form of the mechanical device or mechanical power for the regulation of the downward movement of the rammer in predetermined proportion to the upward withdrawal of the form. In Figs. 3, 4 and 5 I have shown other mechanical devices or powers which could be substituted for the one shown in Fig. 2- for the aforesaid purposes. Although I have shown these mechanical devices or mechanical powers as those best suited for purposes of this invention I do not intend to limit myself to the devices shown, but the use of any wellknown mechanical equivalent for the same purposes shown is within the scope of my invention.

Referring particularly to Figs. 1 and 2, my apparatus is carrie on a frame 1 and is provided with the usual upright portions or leads 2 which carry a steam hammer 3.

" vided a mechanical or rammer into the ground at the desired point. The dolly or rammer is then removed and the hollow form filled with freshly mixed concrete. The problem then is to properly withdraw the form without injury to the formed concrete pile. As shown in Fig. 2, I provide a collar 6 which is adapted to fit under a shoulder 7 of the form 5. Pulleys 8, 8, operated by cables 9, '9, are hooked onto the shoulder 7 and also onto a cross arm which bears on the hammer 3, which in turn bears on the dolly or rammer 4 placed upon the top of the already formed concrete pile. The ends of the cables 9 are suitably secured to the pulley blocks as, for example, being attached to the connection 12 or otherwise in any well-known manner. When it is desired to withdraw the form 5 the cables 9, 9, are operated in the direction of the arrow in Fig. 1 by means of a hoist engine or any other means of power. The cross arm 10 and the collar 6 are thereby drawn together, and the casing 5 withdrawn from the ground. The reaction pressure from this withdrawal will in this case be borne through the cross arm 10 and the rammer 4 directly onto the already formed concrete pile. As previously stated certain disadvantages result from the placing of all the reaction pressure upon the concrete pile, in that the concrete is forced downward too rapidly and tends to mushroom at the base of the pile. In order to prevent this, I have prodevice or mechanical power attached atone end to the rammer and at the other end to the form. This mechanical device or mechanical power consists of a cable 11 capable of being attached to the block 8 by a hook 12. The cable 11. runs over a sheave 13 and a numberof times around sheaves 14, 14, finally being carried to a hammer drum 15. The cable 11 operated by the hammer drum 15 can function as the hammer line during the process of pile driving. When the form is to he withdrawn the hammer drum 15 is dogged and becomes a dead-end to cable 11. It can be seen that cable 11 when dead-ended at 15 operates as a mechanical device or mechanical power regulating the amount of downward movement permitted to the cross arm 10 and the rammer 5 in proportion to the amount of upward movement of the form 5 during its withdrawal since the end 12 of the cable llmoves upwardly with the collar 6 and form 5. The pulley block 14, cross arm 10 and rammer 4 are accordingly drawn downwardly a fraction of a distance through which the form is raised. The right proportion can be secured by a suitable arrangement of thecable 11 and the number of sheaves 14, 14. The form 5 as it is withdrawn leaves certain vacancies surrounding the formed concrete pile, such as at 16 in Fig. 2. The rammer should be permitted a downward movement just sufiicient to force enough concrete into these vacancies at 16 to fill them. If this is done a concrete pile of uniform cross-section will be formed. There will be no mushrooming at the base, nor will there be any jamming or arching due to excessive or insufficient pressure applied to the pile. The amount of reaction pressure not applied to the concrete pile on account of the mechanical device or mechanical power described will be borne by the frame itself and-transmitted to the surface of the ground at the top of the pile. Since a substantial part of this reaction pressure is transmitted to the concrete pile, the react-ion pressure carried through the frame to the surface of the ground will be lessened and there will be less tendency for the frame to sink into the ground.

In Fig. 3 a substitute form of mechanical device or mechanical power for regulating the proportion of downward movement: of the rammer, is shown. A cable 20 is attached to the collar of the form at 21 and is wound around the large portion of a drum 22. Another cable 23 is wound around the small portion 24 of the same drum and is dead-ended on the hammer at 25. A sepa rate hammer line would be necessary with this modification. The drum 22 is free to revolve. The proportion of downward movement of the rammcr allowed to the upward withdrawal of the form is regulated by the size of the respective portions of the drum 22 and 24.

In Fig. 4 the mechanical device or power consists of a chain 30, which engages with a toothed sheave 31 in the upper pulley block 8'. This wheel can'be keyed to the shaft of block 8 as can any of the other sheaves. The cable 9 will rotate the locked sheave and with it the toothed sheave 31, and thereby cause a movement of chain and of screw and nut 33 slackening off cable 34. By this means the downward movement of the rammer is proportionate to the upward withdrawal of the casing. Cable 34 can be used as the hammer line if desired.

In Fig. 5 the construction is similar that in Fig. 4 in that the cable or chain 36 is operatedby having the pulley therefor keyed to the same shaft as one of the other pulleys in block 37. The raising of the pulley blocks 37' as the form is withdrawn thus causes a rotation of the upper pulley 37, which rotation is transmitted through the reduction gears to the drum carried by the gear wheel 35, whereby the hammer 3 is allowed to descend to some extent as the form is withdrawn.

From the foregoing modifications it can be seen that the downward movement of the rammer may be proportionate directly to the upward withdrawal of the form or indirectly thereto, and my claims of invention are expressly intended. to cover the relative movements of the rammer and the form whether controlled directly or indirectly one to the other.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. The process of withdrawing from the ground a form surrounding a formed concrete pile, and dividing the reaction pressure from said withdrawal between the formed concrete pile and the surface of the ground in a substantially constant predetermined proportion.

2. The process of withdrawing from the ground a form surrounding a formed concrete pile and dividing the reaction pressure from said withdrawal between the formed concrete pile and the surface of the ground so that the downward movement jof the concrete in the concrete pile is substantially proportional to the upward movement of the form.

3. The process of withdrawing from the ground a form surrounding a formed concrete pile by transmitting the reaction pressure from said withdrawal through a rammer to the said concrete pile and by using means between said rammer and said form whereby the rammer is permitted a downward movement in a predetermined proportion, to the upward withdrawal lof the form. 4. The process of withdrawing from the,

a form surrounding a formed con crete pile by transmitting the reaction pressure from said withdrawal through a rammer to the said concrete pile and by mean'sof a mechanical device automatically regulating the amount of downward movement of the rammer in a predetermined proportion; to the upward withdrawal of the form.

5. In' a concrete pile forming apparatus of the character drawing from the ground a form surrounding a formed concrete pile, said means ground adapted to divide the pressure reaction accompanying said withdrawal in a substantially unvarying predetermined proportion between the formed concrete pile and the surface of the ground.

6. In a concrete pile forming apparatus of the character described, means for withdrawing from the ground a form surrounddescribed, means for withing a formed concrete pile, said means adapted to divide the pressure reaction accompanying said withdrawal between the formed concrete pile and the surface of the ground so that the concrete in the pile is forced downwardly ata substantially uniform rate whereby to compensate for the vacancies caused by the withdrawal of the form.

7 In a concrete pile forming apparatus of the character described, means for withdrawing from the ground a form surrounding a formed concrete pile comprising means adapted to withdraw said form and to transmit the reaction pressure through a rammer to said concrete pile, and means dividing said reaction pressure between said concrete pile and the surface of the ground in a substantially constant predetermined proportion.

8. In a concrete pile forming apparatus of the character described, means for withdrawing from the ground a form surrounding a formed concrete pile comprising means adapted to withdraw said form and to transmit the reaction pressure through a rammer to said concrete pile, and means dividing said reaction pressure between said concrete pile and the surface of the ground so that the concrete in the ile is forced downwardly with a substantially constant pressure as said form is raised whereby to compensate for the vacancies caused by the withdrawal of the form. v 1 9. In a concrete pile forming apparatus of the character described, means for withdrawing from the ground a form surrounding a formed concrete pile comprising pulle s adapted to withdraw said form and a apted to be attached to said form and to a rammer resting on said concrete pile, and a mechanical device regulating the downward movement of the rammer in a definite predetermined proportion to the upward movement of the form.

10. In a pile forming apparatus of the character described, means for withdrawing from the ground a form surrounding a formed pile, a rammer adapted to rest on said pile, mechanical connections causing said rammer to descend in substantially constant predetermined proportion to the distance said form is raised,

In testimony whereof, I have signed my name to this specification.

JOSEPH HARRY THORNLEY.

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