US1629622A - Construction of concrete piles or columns - Google Patents

Description

1927. May A. HlLEY CONSTRUCTION OF CONCRETE FILES OR COLUMNS 3 Sheets-Sheet 1 Filed Jan. 25. 1923 Gam M I nwmi A. HILEY CONSTRUCTION OF CONCRETE FILES OR COLUMNS Filed Jan. 25. 192FS W 24 A. HILEY CONSTRUCTION OF CONCRETE FILES 0R COLUMNS s Sheets-Sheet 3 Filed Jan. 25, 1923 Patented May 24, 1927.

UNITED STATES PATENT orrlcs.

ALFRED HILEY, OF RICKMANSWOBTH, ENGDAND, ASSIGNOB OF ONE-HALF T EDWARD LE DAB, 0] LONDON, ENGLAND.

CONSTRUCTION OI CONCRETE DILES OR COLUMNS.

Application filed January 25, 1823, Serial No. 615,482, and in Great Britain February 17, 1922.

upwardly and downwardly striking hammer, the pile being built up by a succession of operations each of which involves the depositing of a portion of the concrete from the tube by an upward movement of the latter occasioned by the upward blow of the hammer which frees the concrete so that it falls down the tube by gravity, and the tamping of the deposited concrete by a downward movement of the tube under the combined influence of gravity and the force exerted by the downward blow of the hammer. Or, stated more precisely, the proposed method comprises placing a tube in a ile hole, filling the tube with concrete, and imparting upward and downward impacts to the tube to cause it to vibrate vertically, whereby a portion of the concrete is freed by the upward motion of the tube and falls by gravity and the deposited concrete is then tamped and consolidated by the downward movement of the tube under the influence of gravity and the downward impact, and the pile thus built up by successive operations. During these operations the tube, whose weight is approximately sustained throughout by the pull exerted through suspension ropes put in tension from a purchase or winch. rises in the hole upon the concrete pile that is being built up. The said hammer is preferably the one used for driving the tube when forming the hole and is so constructed as to enable it to furnish energy to the oscillating mass of the tube principally by the sharp impact. of forcible blows exerted in the upward direction against resistance of the ground friction and of gravity, and to give, after each upward blow, a-blow of -moderated force in the downward direction which, aided in this case by the force of gravity, need only be sufiic ent to overcome any excess of ground friction on the tube and cause the tube to plunge sufiiciently energetically on the top of the concrete already deposited to mechanlcally stir or displace it and press itto give the desired degree of consolidation.

In order that the said invention may be clearly understood and readily carried into effect, the same will now be described more fully with reference to the accompanying drawings, in which Figure 1 is a side view showing one form 0% apparatus for'carrying the invention into e ec Figure 2 is a side view showing how the tube is driven into the ground, this tube serving both as the driving tube and as the concrete depositing and tamping tube.

Flgure 3 is a section on a larger scale showing the preferred shape of the driving shoe and the lower end of the tube,

Figure 4 is a front view of the essential parts of Figure 1,

Figure 5 is a side elevation on a larger scale than Figure 1 showing the upper portion of the hammer and the parts associated with it, and

Figure 6 is a side elevation on a larger scale than Figure 1 showing the lower portion of the hammer and the parts associated with it.

Figures 7 and 8 are front elevations on a larger scale than Figure 4 showing the upper and lower ortions of the hammer and the parts assoclated therewith.

A is the aforesaid tube operated upon by a hammer which in the example shown is of the semi-automatic type, viz, one in which steam or other motive fluid is admitted to the heavy vertical cylinder B and by acting on the upper surface of a stationary piston B (Fig-7) causes the cylinder to perform its upward stroke on the completion of which the steam is exhausted and the cylinder falls under the action of gravity and strikes its blow on the helmet or cap A of the tube A, When the tube has been driven in this manner until a safe bearing re- 'sistance below the shoe A has been reached,

' through an aperture a in the casting A while its head is conveniently near the ground.

The hammer and cap are then lowered into their places on the tube and a pair of strong steel links C, C are fitted on to the tube casting A which is provided with suitable projections a a to engage with and take the pull from the links. The upper parts. of the links carry blocks C, C

- which serve the function of an anvil to receive the upward blows imparted by the cylinder head I). The stroke for the purpose of extracting the tube is made approximately only one fourth of the length of the stroke used in the hammer for the purpose of driving. Consequently a convenient space remains at the upper ends of the connecting links to allow of the fitting of relief springs C C connected to the suspension ropes C C The links C, C are provided with tie bolts 0, c at their lower ends to bind them firmly to the aforesaid projections a a The links at their upper parts fit along the opposite sides of the cylinder head I) and extend some distance clear above it and at these free upper ends cross connections a, c are provided to retain the links correctly in their working positions. The links thus function as transmitters of upward impulses to the tube and may be regarded as a portable skeleton -framework or cover within which the kinetic member of the hammer travels to and fro in its successive strokes. As stated before, the upward velocity of the hammer is arrested by impact against the anvil blocks 0, C of the links (preferably through pads C Figures 5 and 7of comparatively soft metal or hard wood) the force of the downward blow being simply delivered in the ordinary manner on the cap A of the tube assisted by the steam pressure above the piston transmitted to the cap A by the piston rod.

In hammers of the type under consideration, a valve D" (Figure 7) actuated by a lever D is generally fitted at the head of the hollow stationary piston rod 6 and a downward pull of the lever by means of a hand line D admits the steam to the cylinder B through the hollow piston rod 12 to cause cylinder to fall. In employing the hammer for the purpose of extracting the tube A in accordance with this invention, an auxiliary check line D? connected to the lever D is operated by the engagement of a projection b (Figure 5) on the cylinder head I) with a nut or block d on the cheek line D to admit steam at a predetermined position during the downward stroke of the hammer so as to give the desired amount of cushioning. The operator pulling on the main hand line D has only to maintain the lever in its lowermost position until the upward blow has been delivered, after which by releasing his pull on the hand line D (which can for convenience when extracting be removed from the end of the lever D and be attached to the lower end of the check line D as in dicated in Figure 1) the valve moves back to the exhaust position; Thereupon the cylinder falls and the admission of the steam is again effected by the automatic actuation of the check line D which is in use only when the hammer is used for extracting. Automatic means of tripping the lever at the end of the upward stroke could be arranged to actuate the valve without the hand line D needing to be used but to preserve more latitude in the control it is pre-. ferred to utilize the hand line D as usuall fitted, and to also add the check line D to ensure the necessary precision for the inlet of the steam. Thus if it were desired to stop the hammer for a short interval, all that is necessary to do is for the operator to maintain a pull on the hand line D to keep ing the downward movement of the tube the aforesaid nut or block d on the check line can be adjusted to come into action a little later than would normally be arranged so that the hammer is allowed to get nearer to the end of its fall before being cushioned and this permits agreater downward blow to be exerted. The said check line D may have a spring or elastic connection D (see Figure 5) which permits the block (1 to be moved by the cylinder head to a greater extent than that necessary to open the valve. The hammer cylinder may have a small aperture B (Figure 7 in the side at a point such that it will be opened near the end of the upward stroke so as to permit the escape of any condensed steam that may lie above the piston. This aperture requires to be sealed when the hammer is being used for driving.

With small resistances which are appreciably less than the weight of the suspended oscillating parts of the tube and hammer, onl a moderately gentle downward blow will be required, and the degree to which the downward force of the blow is cushioned will correspond with the adjustment given to the check line D to open the steam inlet earlier in the downward stroke. In conditions where moderate resistances prevail a certain natural period of vibration of the suspended mass will tend to occur, and in this case the man actuating the hand line D can observe whether he is suiting his movements to the periodic time, and then act accordingly.

The lower end of the tube, which provides the tamping area for pressing on the concrete, may, in its simplest form, be provided by the area of the plain tube itself, as the thickness of the tube necessitated by the driving forces will generally give a suflicient tamping area. For long tubes :3. larger tamping area may be preferable and this can readily be obtained by locally thickening the tube, for example by fitting a metal band A (Figure 3) within the lower end of the tube A and shaping its upper edge so as to avoid any ledge to form an obstruction to the free flow of the concrete. This band may be introduced in segments and welded to the tube.

As the tube in its ascent has a large number of up and down movements, the ground will have pressed in upon the exterior of the tube and as in long tubes the vertical axis may not'be strictly perpendicular there exists a liability of the tube, when plain, scraping the soil during the downward movements. To press out smoothly and clear away any soil in the hole so that the concrete shall be able to emerge from the mouth of the tube into a neat cavity and preserve its good quality free from admixture of earth until it contacts with the walls of the hole, a smooth steel band A (Figure 3) having a convex outer surface is fitted on the exterior of the tube near its lower extremity. This band which is of substantially the same external diameter as the rim of the shoe may be welded on to the tube.

and acts in the manner of a smoothing iron to neatly finish of? the surface of the hole.

The pile shoe A is formed with a rim a (Figure 3) on its outer edge to allow the tube to fit therein, and aflords an uninterrupted passage for the concrete to flow outwards above the detachable shoe immediately any upward movement of the tube takes place under the blows of the hammer.

The suspension rope or ropes C, C which support theweight of the tube and hammer and their associated arts, are carried over the head pulley a o the pilin frame A and connected through a manifo d purchase to the drum of a winch E. The standin part of thepurchase is referably secure in a non-rigid manner t rough the intermediary of a sprin 6 (Figure 1). Extra resiliency is thus obtained in the hoisting tackle which protects the winch rope from receiving any undue pull and also enables the pull exerted on the suspended mass to.

be gauged by the winch man.

I or cases where piles are required to be made in water-covered grounda li ht steel casing may be fitted around the tu e A so that it can ,follow the shoe and enter the ground a suflicient distance with its u per end a suitable distance above water. ntil this position is reached the head of the said casing is kept clamped firmly on to the tube.

After this the clamp is released which allows the pile tube and shoe to continue to be driven downwards whilst the casing reconcrete and imparting upward and downward impacts to the tube to cause the tube to vibrate vertically whereby a portion of the concrete is freed by the upward motion of the tube caused by the upward impact and falls by gravity, and the deposited concrete is then-tamped and consolidated by the downward movement of the tube under the influence of gravity and the downward impact, and the pile is thus built up in suc- 1 cessive operations.

2. An apparatus for carrying out the process claimed in claim 1 comprising a tube, a hammer, an anvil for receiving the blows of the hammer in one direction, connections between the anvil and the tube for causing the blows on said anvil to exert upward pulls on said tube, a second anvil arranged to receive the blows of-the hammer in I the other direction, said second anvil being arranged to transmit said last named blows to the tube to impart downward movements thereto said hammer alternately transmitting blows to said upward anvil and said downward anvil.

3. An apparatus for carrying out the method of claim 1 comprising a driving tube, afiuid operated driving hammer, an anvil for receiving the blows of the'hammer in one dlrection, connections betweenthe anv1l 'and the tube for causing the blows on'said' anvil to exert upward pulls on said tube, a second anvil arranged to receive the blows of the hammer in the other direction, said second anvil being arranged to transmit said last named blows to the tube to impart downward movements thereto, a valve controlling admission of fluidtothe hammer, a valve lever and a check line adapted to be operated by a moving part of the hammer during its downward movement to open said valve and thereby cushion the downward impact of the hammer.v

' ALFRED HILEY.

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