US 3263431 A
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L. J. PHARES Aug. 2, 1966 INSTALLATION OF FILE SHELLS AND APPARATUS THEREFOR 2 Sheets-Sheet 1 Filed July 5, 1963 2, 1956 L. J. PHARES 3,263,431
INSTALLATION OF FILE SHELLS AND APPARATUS THEREFOR Filed July 3, 1965 2 Sheets-Sheet 2 FIG. .54 1t 1 i 2%. 5B
U \fli United States Patent 3,263,431 INSTALLATION OF PILE SHELLS AND APPARATUS THEREFOR Lindsey J. Phares, Butler, N.J., assignor to Raymond International Inc., New York, N.Y., a corporation of New Jerse y Filed July 3, 1963, Ser. No. 292,704
7 Claims. (Cl. 6153.5)
This invention relates to methods and means for driving shells into the earth for use in the formation of concrete piles, the invention being more particularly concerned with the driving of relatively inexpensive sheet metal tapered shells, this application comprising a continuation-impart of application Serial No. 255,562, filed February 1, 1963 and now abandoned.
Heretofore efforts in driving such tapered shells have been made as by the use of a one-piece mandrel tapered closely to fit the shell, but the heavy and repeated driving blows applied to such a mandrel fitting within such a tapered shell, have under some circumstances involved difficulties in that the shell becomes very tightly engaged on the mandrel, thus presenting a serious problem in withdrawing the mandrel due to the friction thereby established between the shell and the mandrel.
Furthermore if collapsible types of mandrels are attempted to be used for driving such plain sheet metal tapered shells, some troublesome difficulties may be incurred due to breakage of the mandrels or parts of the mechanism thereof under continued driving conditions.
Another difficulty which has been encountered in the use of plain steel tapered pile shells has involved the expense of the heretofore proposed welded constructional features at the ends of the shell sections and the possibilities of ruptures and leakages at such welded joints.
In accordance with the present invention, the abovenoted difficulties may be avoided while still being able to utilize plain steel tapered pile shell sections of fairly light gauge metal and hence relatively inexpensive, and while avoiding, if desired, the expense of using welded joints between the shell sections, and while minimizing the likelihood of leakage at such joints, as may have heretofore tended to occur in certain types of ground.
These advantages are made possible with the present invention by utilizing a simple form of rigid non-collapsible steel mandrel which is in effect tapered, with the taper corresponding generally to that of the desired shell which is to receive same, but the taper, instead of being continuous and uniform, is formed by reason of a succession of preferably cylindrical surfaces, each succeeding one of which, from the lower end of the mandrel to the upper portion thereof, being of slightly larger diameter than the preceding one. That is, at the upper end of each of these surface portions, there is a step or corner lformation demarking the lower end of the portion which is next above on the mandrel.
The shell may be formed of two or more steel sections which have a plain or straight-sided taper corresponding substantially to the above-described overall tapered effect on the mandrel. The upper end of one shell section may be made to embrace and slidably overlap the lower end of the section next above without being welded thereto; and the lower end of the lowermost shell section may be similarly overlapped and embraced by a skirt portion on the boot for the shell. The upper end of the upper 3,263 ,43 l Patented August 2, 1966 shell section may be similarly positioned to overlap and slidably embrace a short tapered skirt depending from 7 another and upper portion of the pile, for example such as a so-ca'lled adapter.
In preparing to drive such a pile shell in accordance with the invention, such mandrel is shelled up, that is, positioned within a surrounding shell having preferably a plurality of shell sections as above referred to and with a. boot at the bottom and whatever adapter means, if any, as may be desired to be used at the top. Then the assembly is driven into the ground by pile-driving hammer blows applied to the mandrel in the usual way. As a result, the abovementioned corners formed on the mandrel where each cylindrical portion is interrupted and succeeded by a slightly larger cylindrical portion thereabove, will act to engage and in effect tend to catch on the shell and pull the same downwardly as the assembly is driven. Each such circumferential corner will tend to drag down principally the portion of the shell between such corner and the next such corner above. And due to stretching of the metal that will tend to take place in the shell as the driving progresses, the shell may assume a slightly corrugated effect at the location of each of such corners on the mandrel. As a result of such engagements of the mandrel with the shell, the frictional effects between the shell and the mandrel will be concentrated at the corner formations and so minimized as greatly to facilitate the withdrawal of the mandrel after the shell has been driven, and without incurring any troublesome or prohibitive friction against such withdrawal. The small circumferential corrugation effects produced on the shell walls will tend to strengthen the shell and enable same better to resist collapse due to external pressures.
At the same time, the end portions of each shell section being arranged to embrace the next adjacent members of the construction, will be somewhat slidable in respect thereto and tend to become tight-fitting upon stretching of the shell metal, and thus form joints free of leakage possibilities without resorting to welded joints at the ends of the shell sections and thus without danger of disrupting any welded joints such as might permit leakage of the shell.
The successive portions of the mandrel, each of which is of slightly larger size than the next below, need not necessarily be cylindrical, but may, if desired, of course, be slightly tapered upwardly and outwardly in some cases, or otherwise shaped to be of successively larger and larger sizes, as long as there is a corner-like configuration for engaging the shell where each such mandrel portion joins the next larger one above.
While the mandrel in accordance with the invention may be made of a single hollow integral piece of steel, yet in some cases it may be preferred to make the same of a plurality of sections one above another and with suitable joints therebetween allowing for loose play between sections whereby upon removal of the mandrel, each succeeding section starting from the top may be dislodged against frictional engagement in the shell and at the same time apply an abrupt jarring impact to the section next below to aid in dislodging the latter from its frictional engagement with the shell.
Various further and more specific objects, features and advantages of the invention will appear from the description given below, taken in connection with the accompanying drawings, illustrating by way of example preferred forms of the invention.
In the drawings:
FIG. 1 is a side view showing the driving core or mandrel construction and showing in section the pile shell and associated parts as assembled on the core ready for driving;
FIG. 2 is an enlarged sectional view, partly broken away, showing the portions of FIG. 1 at the region where the upper end of the shell joins typical adapter means thereabove;
FIG. 3 is an enlarged sectional view showing portions of FIG. 1 where one of the shell sections joins another;
FIG. 4 is an enlarged sectional view, partly broken away, showing portions at the bottom region of FIG. 1;
FIGS. 5A and 5B respectively, are sectional views of the upper and lower portions of another embodiment of the invention; and
FIG. 6 is an enlarged cross-sectional view of one of the step or corner formations as above referred to.
Referring to the drawings in further detail, a steel driving core or mandrel is indicated generally at 10 comprised, as will be noted, of a series of portions, typical ones of which are indicated at 11 and 12 and others as at 13 and 14. If desired, such mandrel may be formed of one integral piece of steel with a hollow central portion. Each of the portions thereof as at 11, 12, 13, 14 etc. is preferably of cylindrical shape and each succeeding portion, one above the next, is of slightly larger diameter, so that circumferential corner-like configurations as at 15 will occur where each portions joins the next. Also, if preferred, the uppermost portions as at 11, 12 may have a greater vertical dimension than the lowermost portions such as at 13, 14 so that at the lower portions the corner configurations will occur at more closely spaced intervals. The bottom of the mandrel may be formed with a cylindrical portion 16 with a portion as at 17 protruding downwardly therefrom as indicated, these portions being adapted to be received within a boot construction indicated generally at 18 and hereinafter described in further detail.
The upper portion of the mandrel may continue on up through suitable adapter means for forming the upper part of the pile shell structure, such adapter means in the form shown comprising a step-tapered pile shell of known type, as indicated generally at 20, the lower end edge of which, as best shown in FIG. 2, may be welded as at 21 to a so-called collar ring 22, on the lower edge of which there is suspended a sheet metal, generally cylindrical skirt member 23, welded thereto as at 24. The mandrel 10, as indicated in FIG. 2, may be provided with a step, as indicated at 25, adapted to engage with driving pressure against the interior shoulder in the collar ring 22.
The bottom end of the mandrel may be received in the boot construction 18 of a form sometimes referred to as a milk can type of boot comprised of a rigid boot ring 26, formed with an internal flange 27, against which the peripheral bottom part of mandrel portion 16 bears with driving engagement, the bottom end portion 17 of the mandrel .being received within this ring, and the bottom of the ring being closed by a boot plate 28 which may be peripherally welded as at 29 to the lower edge of the ring 26. The upper portion of the ring 26 is formed with an upstanding flange as at 30, which is embraced by the lower end of a sheet metal tubular member 31, this member being welded in place as at 32 at its lower end edge, and extending upwardly about the lower end portions of one of the shell sections, as will be hereinafter further described.
With the particular example of the invention as here disclosed, the pile shell with which this invention is particularly concerned, is shown as comprised of a plurality of sections such as a lower section 35 and an upper section 36, each formed of tubular sheet steel and each being smooth-walled and nearly of cylindrical form, but tapered with a taper such as to correspond to the overall generally tapered effect on the mandrel. That is, the taper should be such that when the arrangement is initially shelled up, the shell sections will rather loosely fit at the various levels around the successive mandrel portions and contacting with the above-mentioned corner" configurations thereon, but upon the assembly being driven into the earth, such corners on the mandrel portions and closely adjacent regions just above each, will come into tight gripping engagement with circumferential areas around within the shell sections and cause or tend to cause same to be deformed somewhat outwardly and generally preferably so that there will even be a slight corrugation effect at each of such corners. Such engagement of the mandrel, with the shell construction embraced thereby, will cause that portion of the shell between each of such corners and the next above, to be forcefully drawn downwardly for driving the shell into the earth.
It will be noted that where the lower shell section 35, for example, joins the upper shell section 36, the lower end of the latter is initially closely embraced by the upper end portions of the shell section 35 and the uppermost portions of the latter may, if desired, flare outwardly somewhat, as indicated at 35 in FIG. 3, with somewhat of a space as at 40 between the two shell portions. However, as the driving proceeds, the forceful downward pulling impacts which are applied at spaced-apart levels to the sheet metal, will cause the latter to be progressively stretched substantially. For example, if the shell as shown is of a length of some fifteen feet, such stretching may amount to as much as eight to nine inches, and during the process of stretching, the upper portion of shell section 35, for example, will become constricted in diameter to an extent such that same will somewhat slidably come into tight gripping and substantially watertight sealing and embracing engagement with the lower portion of shell section 36, thus providing a shell, although made of sections, in a form which will be free of leakage of ground water into the pile shell, but without the necessity of welding one shell section to the next and thus not only avoiding the labor and expense of any such welding, but avoiding any danger that there will be a welded region which might become disrupted during driving of the shell.
At the upper end of the shell structure shown in FIGS. 1 and 2, the skirt 23, as suspended from the collar ring 22, may have a telescopic and somewhat slidable engagement with the upper end portion of shell section 36, so that here, as in the case of the parts indicated at 35, 35', 36 and 40 in FIG. 3, there will similarly be an arrangement whereby the upper end of the shell section 36 comes into watertight engagement with the skirt portion 23. The same effect is also accomplished at the lower end of the shell with respect to its engagement with the upstanding sheet metal tubular portion 31 of the boot construction. The similarity of the engagement of the sheet metal parts at the juncture of the shell sections at the midportion of the shell with those at the upper portion and at the lower portion, will be apparent by comparing the upper portion of FIG. 4 with FIG. 3, and the lower portion of FIG. 2 with FIG. 3.
Thus provision is made that, as the shell structure is being driven by the core of mandrel therein, the entire shell from the adapter 20 down to the boot, becomes stretched and constricted at the juncture regions of the parts so that same come into watertight relation without the necessity of any welded joints where the shell sections fit into each other or fit the other parts at the top and bottom.
The embodiment of the invention shown in FIGS. 5A and 5B may be similar to that of FIG. 1, except here the mandrel is formed of a plurality of sections, for example an upper section 45a, an intermediate section 45b, and a section 45!) is shaped to receive a tenon portion 46 having a flange 47 welded as at 48 to the upper end of section 45b. Above the flange 47 another tenon portion 49 extends slidably up into a socket portion 50 within the lower end of mandrel section 45a. Tenon portion 49 may be slidably secured in the socket 50 as by a pin 51, the ends of which are welded in place, this pin passing through a slot 52 in tenon portion 49. Thus, when mandrel section 45a is pulled up for purposes of Withdrawing the mandrel, this upper section alone may be quite easily dislodged against frictional engagement with the shell so that the pin 51 will strike against the upper wall of the slot 52 and apply a suflicient impact thereto to aid substantially in dislodging the next lower mandrel section 4511 from frictional engagement with the shell. Similarly, as section 45b is then drawn up, its tenon and socket joint connection to the lower section 45c will cause an impact to be applied to the latter, aiding in the easy withdrawal of the mandrel from the shell. The tenon and socket joint between sections 45b and 45c may be like or similar to the joint between the two upper sections, although other formations of loose-play joints for the purpose may, of course, be used.
While the configurations, as shown at 15 and 15 in the drawings, are referred to as corners, yet preferably same are not formed as sharp corners, but may be very slightly rounded, as indicated in FIG. 6, and so as to have a radius of the order of A or and so that same will not tend to cut into the sheet metal of the shell. The base portions of each of these steps may be formed with small fillets having a radius, for example, of about 4;", such fillets contributing to the strength of the mandrel.
Although certain particular embodiments of the invention are herein disclosed for purposes of explanation, further modifications thereof, after study of this specification, will be apparent to those skilled in the art to which the invention pertains. Reference should accordingly be had to the appended claims in determining the scope of the invention.
What is claimed and desired to be secured by Letters Patent is:
1. Method for driving a substantially smooth-walled tapered sheet metal pile shell section into the earth, the shell having its smaller end lowermost, which method comprises: placing a mandrel therein to be embraced thereby, which mandrel has an overall taper generally corresponding to that of the shell section and occurring by reason of the mandrel being formed with a succession of mandrel portions one above another and of slightly larger and larger sizes respectively, whereby circumferential corner configurations occur at the junctures of such mandrel portions; driving the assembly of such mandrel with the shell section embraced thereon into the earth, the shell section being formed of a metal of a gauge such that the driving forces cause such corner configurations at each thereof, to outwardly and circumferentially deform somewhat the shell section, the corner configurations respectively causing the shell portions therebetween to be each forcefully pulled downwardly, the frictional engagements between the shell section and the mandrel being largely concentrated at the regions of said configurations; and thereafter withdrawing the mandrel from the driven shell section.
2. Method for driving into the earth a plurality of substantially smooth-walled tapered sheet metal pile shell sections which are assembled by way of having end portions in freely fitting telescopic engagement, the smaller end of the shell being lowermost, which method comprises: placing a freely fitting mandrel therein to be embraced thereby, which mandrel has an overall taper generally corresponding to that of the shell sections and occurring by reason of the mandrel being formed with a succession of mandrel portions one above another and of slightly larger and larger sizes respectively, whereby circumferential corner configurations occur at the junctures of such mandrel portions; driving the assembly of such mandrel with the shell sections embraced thereon into the earth with forces causing such corner configurations oircumferentially to engage frictionally the shell sections and by reason of such engagements, forcefully to pull and somewhat stretch the successive portions of the shell sections, with the frictional engagements largely concentrated at the regions of said corner configurations, such stretching being suflicient to cause the telescopically engaging end port-ions of the sections to become forced into tightafitting engagement; and thereafter withdrawing the mandrel from the driven shell sections.
3. \Apparatus for forming and installing pile shells comprising in combination: a sheet metal substantially smoothwalled pile shell formed of a plurality of sections tapered With their smaller ends lowermost and which are assembled by way of having end portions in telescoping relatively slidable engagement with the lower end of each higher section fitting within the upper end of the next lower section; and a non-collapsible mandrel embraced thereby, said mandrel being formed of a succession of portions one above the next and each slightly larger than the one below, circumferential corner configurations being provided at the juncture of each such portion with the next, said corner configurations being of sizes firmly to engage the interior wall surfaces, at least one of such configurations engaging each of said sections of the tapered shell sections and said shell sections being formed of metal of a gauge such that upon driving blows being applied to the mandrel, each corner configuration will firmly engage and thereby apply driving forces to the respective portions of the shell sections between said configurations and the telescoping ends of the sections will be forced into tight fitting engagement.
4. Apparatus in accordance with the foregoing claim 3 and in which adapter means is provided above the upper end of the pile shell and having a tubular sheet metal skirt depending therefrom which is embraced by the upper end portions of said pile shell.
5. Apparatus in accordance with the foregoing claim 3 and in which the bottom end of said pile shell is closed by a boot means including a tubular sheet metal portion extending up therefrom and embracing the lower end portion of said pile shell.
6. Method for driving a substantially smooth walled tapered sheet metal pile shell section into the earth with its smaller diameter end lowermost, said method comprising the steps of positioning said pile shell section to be driven into the earth, applying to the interior of said pile shell at discrete levels therealong a succession of driving forces which are directed parallel to the longitudinal axis of said shell at a fixed distance therefrom about its entire internal pheriphery at each level simultaneously, and by means of such driving forces operating in conjunction with the tapered shell section, causing a circumferential outward bulging of the shell at each level and the development of circumferential internal shelves which absorb further downward forces.
'7. Apparatus for forming and installing pile shells comprising in combination: a sheet metal substantially smooth-walled tapered shell having its smaller end lowermost, a non-collapsible mandrel embraced thereby and formed of a succession of portions one above the next and each slightly larger than the one below, circumferential corner configurations being provided at the juncture of each such portion with the next, said configurations being of size firmly to engage the entire wall surfaces of the tapered shell for applying driving forces to the respective portions of the shell between said configurations, said mandrel being formed of a plurality of sections, one above another; and means interconnecting said sections, said interconnecting means comprising tenon and socket portions positioned respectively, on adjacent ends of the sections, the tenon portions each being formed with a transverse slot and the socket portions each having a transverse pin affixed therein and extending through an associated slot, the slot being of a length permitting vertical movement of the pin therein and thus also permitting relative longitudinal movement between adjacent mandrel sections whereby eaoh succeeding section, starting from the top, may be individually dislodged against frictional engagement in the shell, and thus may apply a jarring impact to the section next below to aid in dislodging the latter from its frictional engagement with the shell.
References Cited by the Examiner UNITED STATES PATENTS Pierce 61-53.7
Upson 6153.7 Caudill 6153.7 -Rice et al 61-53] Fiore 61-53] X CHARLES E. OCONNELL, Primary Examiner. 0 J. SHAPIRO, Examiner.