US2189071A

US2189071A - Apparatus for the manufacture of concrete pipe

Info

Publication number: US2189071A
Application number: US106747A
Authority: US
Inventors: George W Kopp
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-10-21
Filing date: 1936-10-21
Publication date: 1940-02-06
Anticipated expiration: 1957-02-06

Description

Feb. 6', 1940. 2,189,071

APPARATUS FOR THE MANUFACTURE OF CONCRETE PIPE i G. w. KOPP 2 Sheets-Sheet 1 mm NM mN 0 @M "U T mw L wt 5 s 5 a .A rm k m W n n t n vz Feb. 6, 1940. s. w. KOPP APPARATUS FOR THE MANUFACTURE OF CONCRETE FIFE Filed Oct. 21, 1936 2 Sheets-Sheet 2 by centrifugal processes.

of myimproved mold is that itcan bestripped Patented Feb. 6, 1940 I APPARATUS ort THE MANUFACTURE OF oononn'rn PIPE George 'Kopp, Hicksville, N. Y.

Application October 21,

v :15 Claims.

This invention relates to improvements in apparatus for making concrete pipe by centrifugal processes.

Large amounts of concrete pipe, both plain and reinforced, are successfully made by such processes. The molds are .filled with concrete and rotated by machines which cause the concrete to be formed into a pipe in a very short period of time. It is a long time after the pipe and 'mold are removed from the machine, however, before the moldcjan -be strippedjfmm the" pipe and used again. f r I mold is lined with a thin layer of wax beforebeing filled with concrete. .Afte r a pipe has been formed,-the mold is put .in a steamheated kiln which curies the concrete and melts the wax so that the pipef i s not" tight in the mold, and'the'mold can be removed from the pipe, cleaned, and prepared for use again. Large, pipes remain in the kiln for many hours and each mold cantherefore be used only onceor twice a day. This makes a large number of molds necessaryand materiallyincreases the cost of the pipe by requiring excessive capital investment in molds and kiln equipment. l f It is an object of thisinvention to provide improved mold equipment for making concrete pipe One of the advantages from the pipe immediately after it comes from the mold-rotating machine andhefore the .pipe has been cured. This makes it possible to put the mold back into use on the machine without hereof v delay. I

The economicadvantages of the new design are found in the great reduction in capital investment from that required forthe .solid or onepiece forms of the usualtype, saving of fuel necessaryto generate steam .for curing, the saving of expense for wax, the much less kilnequipment, required, and a general speeding up of production. Other features of the invention relate to the use of the same mold for pipes of diiferent size by changing an inner shell which holds the concrete; to the support of the concrete pipes while they are being cured; and to the retention of moisture in the mold during the spinning opera-, tion. 1

Other objects, features and advantages of the. invention will appear or be. pointed out as the specificationproceeds. I I I In the accompan 'ngdrawingsflforming part N Fig. l is a diagrammatic view of apparatus for making concrete pipe by a centrifugal process;

1936, Serial No. 106,747

Fig. 2 is a longitudinal-sectional view through a moldmade in accordance with this invention;

' Fig. 3 is an enlarged transverse sectional view taken on the line 3-3 of Fig. 2; I Fig. 4 is an enlarged fragmentary, transverse sectional viewtaken on the line 4-4 of Fig. -2; Fig. 5 is a' bottom plan view of the seam cover plate. on a reduced scale; and K Fig. dis a reduced-scale diagram illustrating the operation'of the invention.

Apparatus for making centrifugal pipe is shown diagrammatically in Fig. l, and comprises a mold ll having a running ring l2 by which one end. of them'o-ld is supported from rollers I3. The other end of they mold H has a similar ring M which maybe supported on rollers, or held in a chuck l5 of the spinning and troweling machine. The chuck l5 ,is carried by a shaft ll journaled in afbearing [Band driven through speed reduction gearing" I9 bya motor 20. V

Concreteis put into the mold ll by a trough 22, the end portion of which is shown to the right of the moldin Fig. 1. The trough enters the mold and extends forthe full length of the mold After being pushed all of the way into .the mold the trough is rotated and dumps the concrete which it contains .into the mold.- The trough is then moved into a position where one of its edges bears against the concrete as a trowel to spread it evenly fand'dress its inside surface. The mechanism for moving the trough Z2 isnot shown in Fig. 1 because it is not necessary tov a complete understanding of this invention.

The mold l I may be constructed as shown in Fig. 2. Running rings I2 and M are rigidly connected to opposite ends of longitudinal structural members comprising channels 25. These channels are angularly spaced around the rings [2, l4 and are fastened to the rings by screwsZ'l extending through endplates 28welded to the ends of the channels. The screws 2! thread into the sides of therunning rings. designed to have one end always supported by a chuck, the running ring Mrnay be replaced with an end casting. of smaller diameter than the running ring for insertion inthe jaws of a chuck. The runningrings l2 and M are, solid. In moldshaving running rings split to permit'the mold to On small-size molds nected to the channels by angles 32 prevent the channels from being bowed by centrifugal force when the 'mold is spinning.

An end member 34 is recessed into a face of the running ring I 2 and welded to that ring. The running rings I2 and I4, spigot end ring 29, channels 25, hoops 3|, end member 34, and their respective fastenings comprise a rigid frame which is the runner or carrier form of the improved mold shown in the drawings.

The channels 25 are made thicker at spaced points along their length by welding nuts 36 to the webs of the channels. channels in alinement with the holes through the nuts 36 are tapped to receive pressure screws 38. The end member 34 has threaded holes in line with the channels 25 for receiving pressure screws 38, which may be of somewhat smaller size than the pressure screws 38.

An inner form or shell 42 is constructed of resilient sheet metal or thin plate, andit is this inner form42 that holds the'concrete. The inner form 42 is split and has edges 43 abutting along a longitudinal seam 44, shown at the bottom of. the form in Fig. 3.

A cover plate 46 is connected to the shell 42 by rivets 41, 48 (Figs. 3 and 4) along one side of the seam 44 and this cover plate extends across the seam to prevent the escape of water from inside the shell when the form is rotating. 'That side of the cover plate 46 which is not riveted to the shell 42 isv held against the shell by buttons 50 (Fig. 4) which have stems with reduced ends threaded into the shell. The stems 5| extend through slots 52 in the cover plate 46. These slots are best shown in Fig. 5. The cover plate is free to slide circumferentially with respect to the buttons 58. v I

Referring again to Figs. 2' and 3, the shell 42 has lugs 55 riveted to it close to the pressure screws 38. A portion of each lug 55 is spaced from the surface of the shell 42 and has a slot through which the cooperating pressure screw 38 extends. Each of the pressurescrewshas a block 51 pinned or otherwise secured to its inner end. These blocks 57 pull against the lugs 55 to expand the shell 42 when the pressure screws are turned in a direction to back them away from the shell. When' the pressure screws are turned the other way, the blocks 51 serve. to increase the area of contact for'the pressure, screws 38 against the shell. The pressure screws are in effect means reacting between the carrier form and the inner shell to hold the inner shell to a substantially circular contour and to prevent distortion of the inner shell by centrifugal force when the mold is being turned during the centrifugal operation rf forming a pipe within the shell.

The shell 42 can be removed from the carrier form by relaxing the pressureof the screws 38 and then causin relative rotation of the shell 42 and carrier form so that the screws 38 move beyond the ends of the slots in the lugs and leave the shell free to move axially out of the carrier frame; Inner forms or shells of different diameter can be put'in the outer or carrier form in place of the shell 42. The limits on the shell sizes which can be accommodated in the carrier form shown in the drawing depends upon the inside diameter of the running rings I2, I 4 and upon the length of the pressure screws 38. i A centering ring 59 fits within the spigot end of the shell 42. to permit access to the inside of the mold for measuring. With large size molds using a wet Holes through the This ring is preferably annular mix, the centering ring 59 is replaced with a solid disk to prevent water from being thrown-out of the mold.

An end former ring or pallet 6| fits into the bell end of the shell 42 and has a shoulder abutting against the end of the shell. The' pallet 6| is firmly clamped in the shell when the pressure screws 38' are turned down into contact with the shell, but further insurance against displace,- ment of the pallet is obtained by holding a clamping ring 63 against the end face of the pallet.

The clamping ring 63 is held against the end member 34 and the pallet 6| by wedges 65 driven through pins-86. These pins extend through the end member 34, and the wedges 65 provide a quickermeans for fastening and unfastenin'g the clamping ring than if bolts were used in place of the pins 66.

rivets 48 hold the plate 46 against the shell 42 on v one side of the seam and the buttons 50 hold the plate against the shell .onthe other side of the seam. As the shell is pulled away from the pipe it is, of course, necessary for the edges of the seam 44 to move apart, and such movement 'is possible because of the fact .that thestems 5| of the buttons extend through slots 52 which permit relative movementof the plate 46 and the'stems 5|. 'I'he cover plate 46 .is omitted from Fig. 6 in order to make the diagram clearer andt'o show. the separation of the seam edges. v v

After the pressure screws 38 along'fthe seam 44 have been operated to pull the adjacent portions Y of the shell 42 away from the pipe'68, the pressure screws along the two channels 25'next n'earest'to the seam 44 are backed away, from the pipev to g pull more area of the shell 42..ou t of contact with the pipe. v

As each pressure screw 38is operated to pull the portion of the shell beneath it. away from the pipe88, the stiffness of the shell causes it to pull away from the pipe over considerable area beyond that screw so that after. the pressure screws along the seam and those along the nextchannel on each side of the seam have been operated to pull the shell 42 away from the pipe 68, more than half of the surface of the shell is outof contact with the pipe and the mold can be freely removed from r the pipe unless stuck to the pipe.

If the shell sticks to the pipe; more pressure screws can be backed away from the pipe to pull the shell loose, but such sticking of the pipe and shell is not ordinarily encountered,v and'with mixe or molds where it does occur it. can be avoided by greasing the insideisurface of the shelljbefore filling it with concrete.

The mold is preferably stripped from the pipe with the pipein an upright position and the; pallet 6| at the, lower end of the pipe. The clamp-- ing ring 63 is removed before the mold and pipe are turned upright and the mold is then lowered to rest the pallet on .some supporting surface.

The pressure screws 38 are operated to' loosen the shell 42 from the pipe in the manneri'already described. The backing-01f ofthe screws 38' .re;

leases the pallet 6 I, and since the pallet is removablelongitudinallythe mold can be lifted from the pipe, leaving the piperesti-ng on the-pallet, which serves. asasupport for the freshlytmade pipewhen placed in the curing room. Thus-the entire mold,

with the-exception oi the pallet, is removed as a unit from the pipe, and the mold is made ready to use again immediately by returning the pressure screws to their original positions and replacing the pallet. A new pallet .isput :on the mold forcma'lcing the nextrsection of .pipe because the curing operation requires a substantial lengthof means on the frameadapted to connect with the split inner form and operable to pull at least a part of .said inner form away from the surface of a pipe torfacilitate stripping of the-form from theapipe.

2. Improvements informs for the manufacture, centrifugally, of concrete pipe or the like,

comprising a split sheet metal inner form surrounded by a rigid rrunning form with bolts extending between the forms, and connections be.

tween the bolts and inner form for spreading theinner form to strip it from a pipe.

3. A form for making concrete pipe or the like by a centrifugal process, said form comprising a split, resilient, inner form in which the concrete is held during spinning operation, a rigid, outer form adapted to be supported by the spinning into contact with the outside of the inner shell apparatus, connecting means between the inner and outer forms for expanding the inner form to pull it away from the surface of a pipe made in said inner form, the connecting means in-' cluding lugs on the outside of the inner form,

and screws held by said lugs and extending through the outer form.

4. A form for the manufacture, centrifugally, of concrete pipe or the like, comprising a resilient inner shell for holding the concrete, said inner shell having abutting edges forming a seam lengthwise of the inner shell, a frame surrounding and spaced from the inner shell, a plurality of pressure screws extending through the frame at pointsf spaced lengthwise of and angularly around the shell to prevent any substantial distortion ofthe shell by centrifugal force, and lugs on the outside of the shell in positions to be pulled toward the frame to expand the shell and strip it from the pipe when the screws are turned in one direction.

5. A form for themanufacture, centrifugally, of concrete pipe or the like, comprising a resilient inner; shell for holding the concrete, said inner she-ll having abutting edges forming a seam lengthwise of the inner shell, a frame surrounding and spaced from the inner shell, said frame including end rings connected by a number of angularly-spaced, longitudinal structural members, screws-extending through each of said members at spaced points along its length and into This invention has been described in conneccontact with the resilient inner :shell "to hold :it against distortion by centrifugal force, and lugs secured to the shell under each :of the. screws in position to be pu lled outward when the screw is turned in :a direction to back it away from the shell. h

6. A mold for the manufacture of concrete pipe at the like by the centrifugal process, including combination .za carrier "form adapted to .be rotated, a split shell in the carrier form for holding the. concrete, an end former ring detachably held at one end of the shell, and

means :for stripping the mold from a :pipe including devices on the carrier form operable to release the shell from the pipe whenthe mold is in an upright position with the former ring :un-

.der the lower end of the pipe, said former ring serving as a support on which the pipe can rest during the curing operation.

7. Apparatus for the centrifugal manufacture ner form, an inner moldfcarried in "the runner vform and. adapted :to hold the concrete, said inher mold-being expansible radially of the pipe to strip-said :mold from .the pipe, :m-eanson therun- .ner'iorm operable to cause such expansiblemovement of the inner mold, and a pallet at one end of the inner mold )for forming one end of the pipe, said pallet being longitudinally releasable from the :mold so that the pipe :can rest on the pallet after the mold has been stripped from the pipe with the pipe in an upright position.

'8. Improvements in molds for manufacturing, 'centr-ifugally, concrete pipe or the like, comprisby a centrifugal process, comprising a runner form with longitudinally extending frame members angularly spaced around the form, a split shell. within the runner form, pressure screws threaded through the frame members at points along the length of the shell and extending radiof concrete, pipe or the like, including a runally intocontact with the shell to hold saidshell to a circular contour and hold the seam edges in substantial abutment, and a cover plate over theseam to prevent the escape of water from within the shell during a spinning operation.

1 10. A mold for making concrete pipe or the like by a centrifugal process, comprising a run- -ner form with longitudinally extending frame members angularly spaced around the form, a split shell within the runner form, lugs attached to the shell and having portions spaced from said shell and with slots extending circumferentially with respect to said shell, means carried by the frame members and extending through said slots to hold the shell against axial movement in the runner form, the shell being axially removable from the runner form by causing reli y f ative rotary movement of the shell and form to release the lugs from the means extending through the slots in the lugs, said means being radially adjustable toward and from the shell toaccommodate a shell. of different size within the runner form. I

11 A form for the centrifugal manufactureof concrete pipe or the like, said form comprising a rigid outer frame structure having one orv more, I

running rings, a split inner shell within the outer frame structure for holding the concrete during the spinning operation, and means 'for expanding carrier form, and means on the carrier form which contact with the split mold at several angularly spaced points around its outside'surface to hold the mold closedand substantially cylindrical in shape during the centrifugal operation of forming a pipe within the mold, said means reacting between the 'carrier form and the split mold and being movable with respect to the carrier form to permit the mold to be stripped from the pipe.

13. A form for the manufacture, centrifugally,

of concrete pipe or the like, comprising a one piece, sheet metal inner shell for holding the concrete, said inner shell having'longitudinally extending edges movable circumferentially with respect to one another to expand the inner shell when a pipe is to be removed from the mold, a frame surrounding and spaced from the sheet metal inner shell, a plurality of pressure devices on the frame extending into contact with the outside of the sheet metal shell at points spaced lengthwise of and angularly around the shellto give the shell a substantially circular contour and to prevent any substantialdistortion of the shell centrifugal force, ndlugs on the outside bf,

the shell m positions to be pulled toward the 1' frame to expand the shell andstrip it from the pipe when the pressure devices are moved in one direction. 1

14. A composite form for the centrifugal manufacture of concrete pipe or the like, said form comprising" a rigid outer frame structure having one or more running rings, a'split inner shell within the outer frame structure for holding the means holding the'outer' frame and inner shell 10 concrete during the spinning operation,- and in assembled relation, said means including de- I vices carried by the outer frame and extending inward to the split inner shell and operable to expand the split inner shell while the rigid outer frame remains unaltered.

, 15. A composite form for the centrifugal man'- ufacture of, concrete pipe or the like, said'form comprising a rigid outer frame structure having one or more running rings, a resilient inner shell within the outer frame structure for holding the concrete during the spinning operation, said resilient shell being split'lengthwise to permit it to open when a pipe is to be removed from the inner shell in assembled relation, said means including several devices reacting between the out apart points around the peripheral surface of the resilient inner shell, to give said resilient shell "25 mold, and means holding the outer frame and.

er frame and the resilient inner shell at spaced a substantially circularcontour and to prevent any substantial distortion'of the shell by centrifugal force.

I GEORGE W. KOPP;