US2425137A

US2425137A - Core form for casting concrete

Info

Publication number: US2425137A
Authority: US
Publication date: 1947-08-05
Anticipated expiration: 1964-08-05

Description

Aug. 5, 1947. A. E. TROIEL I 2 ,1

CORE FORM FOR CASTING CONCRETE TUBES Filed Jan. 13, 1945 2 Sheets-Sheet l INVENTOR.

ARTHUR E. TPO/EL ATTORNE KS Aug. 5, 1947. A. E. TROIEL 7 CORE FORM FOR CASTING CONCRETE TUBES Filed Jan. 13, 1945 2 Sheets-S heet 2 IN VEN TOR.

ARTHUR E. T/PO/EL ATTORNEYS patented Aug. 5, 1947 UNITED STATES PATENT OFFICE CORE FORM FOR CASTING CONCRET-E TUBES Arthur E. Troie'l, Berkeley,..Calif.

Application January 13, 1943, Serial No. 472,'283

3 Claims. ((125-128) The .present invention relates to forms for casting concrete tubes, and particularly to forms formakingpile caps.

Pile caps, sometimes referred to as pile jackets, are usually square tubular reenforced concrete castings which are placed over the upper ends of concrete piles after they have been .driven, the caps being cemented in place. The upper endsof the caps support the floor or wharf for which the piles serve as a foundation and may be fixed at a uniform height, though the piles themselves are driven to different depths.

Such pile caps are preferably cast with rounded corners to prevent chipping away of sharp .edges. They are usually approximately two feet in breadth and may be used in any desired lengths, but are seldom over eight feet long. Because of their size and shape, it is expedient to cast the pile caps horizontally in layers, one on top of another, so that forms used for one layer may be raised and positioned for casting directly on top of the first castings as soon as the concrete has set.

It is the object of the present invention to provide forms for casting concrete pile caps or the like which are simple in construction and easy to strip and set up. 7

A further object is the provision of a form for casting a rectangular tubular shape with an inner form member which may be easily collapsed for withdrawal when the forms are to be stripped.

A still further object of the inventionis-a provision -in the form of the character described of members for producing rounded outside corners,

which members will not interfere with upward stripping of the vertical form walls by which they are carried, and will also leave a slightpimpression in the casting to aid in the positioning of the forms for successive casting in vertical tiers.

Further objects and advantages of the invention are made apparent in the following specification wherein detailed reference is madeto the accompanying drawings.

In the drawings:

Fig. 1 is a central vertical section taken transversely of a form embodying the present invention and illustrating the manner in which itis supported bypreviously made castings;

Fig.2 is a fragmentary perspective view,;i1lustrating certain details .of construction of the form illustrated in Fig. 1;

:Fig. 3 l is a horizontal sectional view taken on lineIII-JII of Fig. 1;

Fig. A -is avperspective view illustrating oneha'lf-ofone of theform'ends shown'in Fig. 3; and

ZE'ig. .;5 is .an enlarged fragmentary perspective view showing a locking device used for securing the v.endjforms to the main inside and outside form members.

InjFig. laconcrete pile, capA D is shown as having gbeen poured in a "form which is set up on topof ;a layer of previously. cast pile caps, portions =of whichyare indicated .at l l. The form inxzwlhi'oh thelcap .liflyhasbeen pouredincludes a pairofus'ide walls J12 (see .also Fig. 3) whichwalls are constructednf relatively thin,metal,,-plate and serve .as ,forms vvfor the adjacent sides of pile capsxwfhich are castin a group-or layer. .Being perfectly flat on :both surfaces .and preferably 'beingsprayedwith alubricant before theconcrete poured, ;the walls 12, after the poured .concre'terhasv set, may be stripped by being raised yertically. 'As the lower :ends of the .wallsextendlbelow {the bottom :ofthe casting, they may heretained, ;a s.shown,.with a few inches of their edge in :place between the caps :previously cast SOiaS..-;tO guide :and support them. In order that the putside. corners .of .th e..cap wi1l be rounded, eachjofnthe sid walls I22 is. provided with .a .pair of concave fillets. at its upper. end, and a similar'ly shaped, though differently constructed, pair of.:fi11etsl:M.:at its lowerend. The upper fillets il:3.=are.'.bent to.;a shapewhich enables them to :be securely riveted, welded, or .otherwise fastened to the Walls 12 in a,. permanent manneras, :being positioned adjacent: the :top of the form, they .do not preventthe :formwallfrom-being stripped upwardly from between adjacent castings. They are preferably bent .upwardly as indicated at 15 :where they v:are .securedto the opposite sides of .thevimembers zl'z/and. where'they are pierced with lhQ'lBS" indicatedat :l 6, which also pass through the members .I2.:to :proyidea purchase: by means of which the .walls may :be pulled upwardly. The lower :fillets zlikflfiSGCllTfid permanently to the side walls, :would :prevent-their .being stripped from between-thecastines, :and therefore, are "formed asseparat memberswhich, as'shown in ig. 1 *aneh l inrlac a th rupper edge by clipsx ;These clips-straddle both of the fillets I l andare shaped :to;;ret ain .-.them against the wall I2 the clips l li-beingreceived in: notches -I8;formed at .the ;upper ends ;of slots -I*9 --which, are somewhat ,widerthan thGEILOtChBS.

QWhen" the concretegis, poured into the form, it isqscreededsflushwyith the top-edgesof the upper fillets ;so= thatwdueto the double thickness of the metal of which these fillets are bent, a slight shoulder, shown at H], is left on the top surface of the casting. As the upper fillets l3 and the lower fillets I4 are of the same dimensions, this shoulder is so positioned that when the forms are stripped upwardly and the lower fillets reset, it supports their lower edges, and when the clips ll have been inserted in a manner to embrace their upper edges, the form walls maybe pressed downwardly and will come to rest on top of the clips; thus the weight of the walls holds the fillets E4 in place while the fillets in turn support the walls at their proper elevation. The reason for the slots l9 being somewhat wider than the notches IS in which the clips I! are received is to facilitate stripping of the side walls 12. When these walls are moved vertically upwardly a short distance, say a half inch or so, the clips I! are released from the notches l8 and as the wider slots l9 pass over the clips, there is no tendency for them to bind or become jammed in the event that the upward movement of the wall is not absolutely vertical at all times. The inner walls of the mould are made up of a substantially square collapsible tube which is formed of four generally right angular members 20. These members are flanged inwardly as indicated at 2| intermediate the corners of the tube and the flanges are connected together by pins 22 which also serve as pivotal supports for sets of links 23 (see also Fig. 3) which are pivoted at their inner ends by pins 24 to the four radial webs of castings 25. Th links and castings are spaced throughout the length of the tubular form member and the castings are connected by rods 26, the ends of which are threaded for reception by the threaded interiors of the castings.

The tubular form may be collapsed sufficiently to permit it to be withdrawn from th interior of the pile cap by means of a jack screw 21 at its forward end which is threaded through a nut 28 supported and braced by links 29 connecting it with the tube by the foremost pins 22, This jack screw is connected through a swivel joint 30 with a short rod 3| which is threaded into the foremost of the castings 25 and retained therein by a lock nut 32. Upon turning of the jack screw, which may be accomplished by application of the wrench to its outer squared end, all of the links 23 will be moved to an inclined position and efiectively shortened with the result that the form walls at which their outer ends are secured will be drawn inwardly. Were the angular sections 20 of the form each made in a single piece projecting the full distance fully into its respective corner, this inward contraction, particularly where relatively stiff metal must be used to support the weight and pressure of the concrete, would cause the corners to be forced outwardly and would eifect binding that would prevent extraction of the tubular form member from the interior of the casting. Consequently, the corners have been constructed in the manner illustrated in Fig. 1 where they are shown as bent on a diagonal indicated at 33 with a central raised or outwardly curved portion 34. A false corner member 35, which is formed of a separate piece of metal and in no way attached to the member 20, is used to complet the corner of the form which was lost in bending it to the plane illustrated at 33. Sufiicient clearance is left between the outwardly curved portion 34 and the member 35 so that when the form is drawn inwardly or collapsed, its corners may expand slightly without causing binding, and it may be Withdrawn leaving the corner form members 35 in place until after the main portion of the form has been completely removed. These corner members 35 may then easily be loosened and extricated. In setting up the form, the lower corner members 35 are first put in place receiving their support from end members presently to be described. The main rectangular member made up of the four angular members 20 is then inserted and thereafter the upper members 35 are slid into place. With this construction, a collapsible inner form member is made practical and simple to remove. The false corner members 35 may be bent to produce any degree of rounding of the inside corners of the casting, or any other desired shape, and the slight Wedge shaped beads 36, which are formed where the false corners join the members 20, may be so small as to be unnoticeable, and do not constitute a disadvantage.

The inner form member and the outer walls ID are held in properly spaced relationship by means of end members which are illustrated at 31 in Fig. 3. These end members, the construction of which is shown in Fig. 4, are formed of a rectangular plate 38 which has its central portion cut out and its inner edges flanged inward- 1y, as shown at 39, to form a complete rectangle, while its outer edges are flanged as indicated at 40, except at the corners which are rounded as shown at 4| to conform in contour to the fillets l3 and I4 which overlap them. These end wall members receive the inner tubular form member and are embraced on two sides by the outer members l2. They are so constructed that they may be secured either to the inner member or the outer member, and by virtue of this arrangement, a tube of any desired length may be cast in a form of standard dimensions. To determine the length of the tube, the forward end member 31 is secured to the outer walls I2 while the rear nd member 31 is secured to the inner members 20. The entire form is therefore in effect telescopic lengthwise so that it may be set up to cast a cap of any length.

While the end walls may be secured to the inner and outer form members in any desired manner it is preferred that the form clamp illustrated in Fig. 5 be used. In this figure one of the outer walls I2 is shown as disposed between flanges 40 of two end members which serve as the front walls of adjacent forms. The forward edges of the member 12 as well as the flanges of the end members are perforated as indicated at 42 in Fig. 4 or may in some instances be provided with elongated slots as shown at 43 to accommodate for slight misalignment. The clamp illustrated in Fig. 5 comprises a pin 44 secured to a plate 45. The pin is passed through aligned perforations in the members to be clamped together, and the plate 45 has a lower portion bent around the members to be clamped as indicated at 46 and a tail 4'! is bent outwardly from this lower portion for convenience in swinging the clamp about the axis of the pin 44 so that after the pin has been inserted, the clamp may be swung downwardly to embrace the members 40 and the member l2 and retain them together.

Reenforcing steel may be placed in the form but is conventional in its construction and arrangement, and is not here illustrated. When the castings are poured, however, it is necessary that the concrete be vigorously agitated to prevent the occurrence of voids, particularly in the bottom wall wherein the concrete must be poured into a horizontally disposed area, the top of which is covered by the lower wall of the inner tubular form. To insure that this lower wall is completely poured, it is preferable that the walls of the members 20 on the lower side be provided with small countersunk perforations as indicated at 48 in Figs. 1 and 3 so that when this wall space is completely filled, small portions of the concrete will ooze upwardly through these perforations where they will serve as visible indication that the space beneath them is full. These small perforations, which need not be more than a quarter of an inch in diameter, leave such a small area of roughness on the interior of the casting that it can scarcely be detected, and due to the fact that they are countersunk, the small quantity of concrete which flows through each perforation usually breaks away on contraction of the inner form without danger of filling the indicating perforations, thus making it unnecessary to clean the perforations before each casting operation. All of the form walls, as has previously been stated, are preferably sprayed with a lubricant before casting to facilitate their being stripped and this is particularly desirable of the vertical walls 12 which must be stripped upwardly from between adjacent castings. The bottom wall, however, which is provided by the top surface of a previously cast cap, except in the first instance where the original layer is cast upon foundation planks suitably arranged for that purpose, may be either covered with a layer of paper to prevent adherence of superimposed castings, or may be heavily lubricated for the same purpose.

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

1. Forms for casting rectangular tubular members including rectangular inner form members, means for contracting the walls of said members to permit them to be stripped from the castings, the corners of said inner form members being bent inwardly to clear the corners of the casting, and separable false corner forms overlying the inwardly bent portions.

2. An inner form for a rectangular tubular member comprising four plates bent to right angles and joined to form a generally rectangular tube, means for bending the walls of said tube inwardly to contract it before stripping it from the shape cast around it, the corners of said tube being bent inwardly to clear the corners of the casting, and false corner forms slidably separable from and overlying the inwardly bent corners.

3. An inner form for a rectangular tubular member comprising four plates bent to right angles and joined to form a generally rectangular tube, means disposed mainly within said tube and engaging said plates at their lines of juncture to draw the walls of the tube inwardly for contracting it before it is stripped from the shape cast around it, the corners of said plate being shaped to clear the corners of the casting, and corner form members slidably separable from and overlying said shaped corners.

ARTHUR E. TROIEL.

REFERENCES CITED The following references are of record in the file of this patent: