US2870513A

US2870513A - Pipe making apparatus

Info

Publication number: US2870513A
Application number: US504413A
Authority: US
Inventors: Archie R Gagne
Original assignee: Individual
Current assignee: Individual
Priority date: 1955-04-28
Filing date: 1955-04-28
Publication date: 1959-01-27
Anticipated expiration: 1976-01-27

Description

Jan. 27, 1959 A, GAGNE 2,870,513

PIPE MAKING APPARATUS Filed April 28, 1955 4 Sheets-Sheet 1 IN VEN TOR.

)0 6 I fl PML Jan. 27, 1959 A. R. GAGNE 2,870,513

PIPE MAKING APPARATUS Filed April 28, 1955 i 4 Shets-Sheet 2 l 4 Ma? PM on MW.

Jan. 27, 1959 A. R. GAGNE PIPE MAKING APPARATUS Filed April 28, 1955 4 Sheets-Sheet 3 Jan. 27, 1959 A. R. GAGNE PIPE MAKING APPARATUS 4 Sheets-Sheet 4 Filed April 28, 1955 8 3 o ww 1.50 0 .0 o 9. 6 2.0. 0.

United States Patent PIPE MAKING APPARATUS Archie R. Ga gne, Homewood, Ill.

Application April 28, 1955, Serial No, 504,413

9 Claims. (Cl. 25-30) This invention relates to pipe making apparatus and more particularly to apparatus for casting concrete pipe.

The apparatus forming the subject matter of this invention is principally applicable to the manufacture of large size concrete pipe of the order of 50" or more in diameter and having a length of the order of five or six feet. The dimensions herein given are exemplary and as v is well understood, the apparatus embodying the invention may be used for the manufacture of pipes larger or smaller in diameter than specified above and having any desired length.

At the present time, concrete pipe of this character is manufactured with a pair of vertically positioned concentric forms disposed on a turntable. The inner form is ordinarily stationary while the outer form is rotated on its axis. During rotation, a damp concrete mix is introduced into the annular region between the opposing form surfaces and the mix is tamped by vertically reciprocated beaters. These beaters tamp the mix as the outer form rotates and carries the mix with it. When the space between the forms is filled with concrete mix, rotation of the outer form is stopped. The inner form and tamping means are raised clear of the machine and the outer form together with the uncured but self-supporting concrete cylinder within the same is taken from the turntable upon which the forms had originally rested. The outer form may then be separated from the concrete and the concrete cylinder may then be cured.

This apparatus, is objectionable for a number of reasons. During the time that the space between the forms is being filled with concrete mix, the outer form is being rotated while the inner form is stationary. This results in relative movement between the inner form and the concrete mix disposed between the concentric forms. The tamping tends to force the mix against the forms while the tendency of the mix to rotate with the outer form tends to create a clearance between the mix and the outer surface of the inner form.

The above action results in considerable wear on the surface of the inner form. This wear requires replacement of forms with consequent expense and also has a tendency to increase the distance between the opposing form surfaces, thus increasing the thickness of the concrete pipe as manufactured. Hence a compromise between undesirable wall thickness of the pipe and increased inside diameter of the pipe on the one hand and the expense incident to replacing the inner form must be effected.

Another serious objection to this general type of pipe making apparatus resides in the fact that the concrete mix can be compacted only by tamping. As is well known in the industry, vibration of the concrete is more effective than tamping, resulting in a denser concrete I having greater strength and less porosity.

2,870,513 Patented Jan. .27,

ICC

the machine.

In general, a machine embodying the present invention utilizes concentric inner and outer forms. However, no attempt is made to move the inner form during the pouring of the concrete mix. Instead, the apparatus embodying the present invention provides means for distributing the mix around the space between the ,forms and also makes it possible to compact the mix during pouring by form vibration. In accordance with the present invention, means are provided for moving the inner form relative to the outer form about the form axis and relative to the mix between the forms just long enough to secure a smooth inner pipe surface. The inner form may be removed from within the concrete cylinder and the outer form and the contained concrete cylinder may then be handled in conventional fashion.

A machine embodying the present invention makes it possible to manufacture larger pipe in longer lengths .in addition to reducing wear on the form, and permits vibration instead of conventional tamping of the concrete mix.

In order that the invention may be understood, it will now be explained in connection with the drawings wherein an exemplary embodiment is illustrated. It is understood that variations may be made within the scope ofv the invention as defined by the appended claims.

Referring to the drawings,

Figure 1 is an elevation of the pipe-making apparatus embodying the present invention, certain parts being cut away for purposes of illustration, the apparatus having concrete and having the top of the concrete shaped.

Figure 2 is an elevation of the apparatus illustrated in Figure 1, the inner form being. elevated in preparation for removal and curing of the concrete.

Figure 3 is a sectional detail on line 33 of Figure 2.

Figure 4 is a transverse section of the inner and outer forms-showing concrete mix disposed therebetween.

Figure 5 is a perspective detail with certain parts broken away illustrating the part of the apparatus for feeding concrete mix to the annular space between the inner and outer forms.

Figure 6 is a detail showing a portion of the inner form and the mold ring in elevated position, clear of the mix, between the inner and outer forms.

Fig. 7 is a detail similar to Figure 6 but showing the mold ring in operating position for shaping the concrete mix to generate the desired pipe end shape.

Figure 8 is a detail illustrating the manner in which the mold ring is supported from an annular angle iron.-

Figure 9 is a perspective detail illustrating a modified form of means for shaping the top end of the mix.

Figure 10 is a detail illustrating the concentric pipe construction for feeding compressed air to the cylinder strength and be capable of absorbing vibration. Base plate 13 supports pallet ring 15 of steel or anyv suitable .material. This ,pallet ring may-be .in one piece orwmay consist of a number of pieces adapted to form a continuous circular structure. Supporting pallet ring are angle blocks 18 bolted at 19 to base plate 13. Angle blocks 18 have flange 2i? projecting into an annular undercut 17 of the pallet ring for engaging the pallet ring and supporting the same. As many angle blocks 18 may be provided as are necessary and in fact, angle blocks 13 may form a generally continuous ring for supporting the pallet ring.

Pallet ring 15 may have any desired shape, depending upon the shape of the end of the pipe to be cast. As illustrated in Figures 1 and 2, pallet ring 15 is shaped to provide a spigot construction for one end of a concrete pipe length.

Between angle blocks 18 and pallet ring 15 is disposed the bottom end of outer casting form 22. Casting form 22 is preferably of steel and may consist of any number of pieces. As illustrated in Figure 4, outer casting form 22 consists of

semi-cylindrical parts

23 and 24 having abutting flanges bolted together.

Attached to the outside of outer form 22 are a number of vibrators 26 each of which is connected by electric cable 27 to control switch 28, the control switch being mounted upon vertical steel tracks to be described later. There may be as many vibrators 26 as are neces sary, each of these vibrator being used for generating vibrations in outer form 22. Such vibrations are communicated to the mix to be disposed within outer form 22 for the purpose of tamping the concrete to insure a dense mix. Inasmuch as such vibrators are well known in the industry, it is unnecessary to describe the same in any detail. Outer form 22 has any desired length axially of the form, the outer form having top free edge 30.

Base plate 13 carries fixed pivot pin 32 located to be coaxial with cylindrical outer form 22. Cooperating with pin 32 is vertically movable shaft 33.- whose bottom end 34 is suitably recessed for accommodating pin 32. Bolted to shaft 33 near the bottom thereof is circular plate 35. Inner cylindrical form 36 is joined to the edge of bottom plate 35, inner form 36 being of steel. The outside diameter of inner form 36 and the inside diameter of outer form 22 are selected to provide proper pipe diameter and pipe wall thickness. It is understood that for different size pipe, it will be necessary to have different size inner and outer forms. To this end, therefore, inner form 36 is so constructed as to be removed from shaft 33 and replaced by a different size form. The outer form may be easily changed, base plate 13 being constructed so that angle blocks 18 may be bolted at various positions.

Inner form 36 has annular region 37 defining what is effectively the top end of the inner form. Inner form 36, however, continues above annular region 37, the extension being indicated generally by 38 and the inner form having top free edge 39. Rigidly attached to inner form 36 at the inside thereof at annular region 37 is top cover plate 41. Top cover plate 41 is suitably bolted to sleeve 42 disposed around the outside of shaft 33. Sleeve 42 may be joined to the shaft or free and as will be apparent later is rotatable therewith.

Inner form 36 is rotated by shaft 33 and is also to be elevated or lowered with the shaft as required. Shaft 33 is hollow for most of its length and is provided with spline 44 extending for a substantial portion of the shaft length. Shaft 33 is also provided with a pair of

collars

45 and 46 rigidly attached thereto. Shaft 33 passes through journal 48 carried by horizontal platform 50 vertically movable as by rollers 51 in a rigid, stationary vertical framework including steel tracks 52. Vertical tracks 52 are connected at the top by a cross beam construction 54 carrying

pulleys

55 and 56.

Pulleys

55 and 56

guide cables

57 and 58 going down to carriage 50 and attached thereto, these cables being adapted to control the vertical position of carriage 50. Any suitable means may be provided for operating

cables

57 and 58, such as for example a winch, so that carriage 50 may travel vertically between the position illustrated in Figure l and the position illustrated in Figure 2.

Cross beam 54 has journal 60 through which shaft 33 passes. Journal 60 rotatively supports bevel gear 61, the bevel being directed downwardly as illustrated in the drawings. Bevel gear 61 is rotatively locked to shaft 33 by means of a key cooperating with spline 44 so that bevel gear 61 may rotate with shaft 33 but will permit shaft 33 to move vertically with respect to the bevel gear.

Disposed within shaft 33 and extending upwardly therece-ncentric inner and

outer pipes

63 and 64 respectively. It is understood that

pipes

63 and 64 are concentric with shaft 33. Pipes 63 and 64- emerge from the top end of shaft 33 and are connected to rotatable coupling 65. Coupling 65 is connected to stationary

concentric hoses

66 and 67 of rubber or the like. Coupling 65 is of a type available on the market for providing a rotary connection between

pipes

63 and 64 on the one hand and stationary concentric pipes or

hoses

66 and 67 on the other hand. Instead of a ball type coupling such as illustrated, any other type of arrangement may be provided, such as for example a pair of stationary sleeves side by side over finished rotating members suitably connected to the respective pipes for establishing rotary con nections. As will be apparent later, except for the necessity for the concentric pipe arrangement on both sides of coupling 65,

concentric pipes

63 and 64 inside of the shaft proper may be replaced by two separate pipes side by side.

Pipes

63 and 64 are provided with

suitable fittings

69 and 70 at regions along shaft 33 disposed at a distance above top cover plate 41. From

fittings

69 and 70, a series of pairs of supply pipes 71 and '72 radiate outwardly. As illustrated in Figure 3, there are three pairs of pipes, the pairs being symmetrically disposed at angles of substantially 120. The number of pairs of pipes and the angular relationship are not important within substantial limits. Each pair of

pipes

71 and 72 extend toward air cylinder 75 disposed vertically and carried by angle iron 76 rigidly attached to the inside of portion 38 of the inner form. Air cylinder 75 is a conventional air cylinder having a piston within the same, the piston having piston rod 77. It will be noted that

pipes

71 and 72 are vertically displaced and enter each air cylinder at the bottom and top respectively. i /hen compressed air is supplied to each pipe 71, it is understood that each piston will be urged upwardly. The reverse will be true when compressed air is supplied to each pipe 72.

The various piston rods 77 are suitably attached to annular angle iron 78 disposed around the outside of portion 38 of the inner form. It will be noted that the lower part of portion 38 of inner form 36 is provided with a series of spaced windows 80. Vertical flange 79 of annular angle iron 78 has a width (the dimension parallel to shaft 33) somewhat greater than the width of windows 80. As illustrated in Figures 6 and 7, annu lar angle iron 78 may be moved vertically. In its bottom position as illustrated in Figure 7, vertical flange 79 will cover windows 80 while the horizontal flange will be about even with the free edge 33 of the outer form. In the top position of the annular angle iron, as illus trated in Figure 6, the angle iron is above windows 80.

The horizontal flange of annular angle iron '73 has bolted thereto at spaced points 32 annular shaping or pallet ring 83. This pallet ring extends outside of portion 38 of the inner form and when the pallet ring is in the position as illustrated in Figure 7, the top end of the mass of cement mix will be shaped to provide a bell.

It is'understood that the mass of shaft 33 and inner form 36 and associated apparatus will be sufficiently great so that when the air cylinders are energized to force pallet ring 83 into the position illustrated in Figure 7, there will be negligible tendency to raise inner form 36 from its bottom position as illustrated in Figure 1. Any elevation of the' shaft and inner form'asscmbly should be accomplished only through

cables

57 and 58.

Rotatively disposed around shaft 33 and within inner form extension 38 and just above top plate 1 is sleeve 85 carrying bevel gear 86 and spider 87. Spider 87 has adjustably attached thereto a number of paddles 88 operating along the top surface of top plate 41. Paddles 88 have a width of about the same order as the width of windows 80 or these paddles may be somewhat wider. Paddles 88 and the spider are adjustably secured by bolts in elongated slots so that these paddles may be adjusted or replaced by difierent paddles for different size pipe. It is clear that paddles 88 will be rotated with bevel gear 86. Cement mix chute 90 pivoted on platform 50 has a discharge end which is adapted to feed cement mix on top of top cover plate 41.

Cooperating alternatively with

gears

61 and 86 are bevel pinion gears 95 and 91 respectively. Bevel gears 95 and 91 are rigidly secured to shaft 92 having spline 93 extending along a substantial portion of the length thereof. Shaft 92 is rotatively coupled to bevel gear94 as by a key, it being understood that shaft 92 is longitudinally movable with respect to bevel gear 94.

The vertical position of shaft 92 may be controlled by any suitable manual means such as, for example, member 96 having a collar portion disposed around shaft 92. Member 96 is here illustrated as being attached to cable 97 so that by pulling on cable 97, shaft 92 may be pulled to its top vertical position as illustrated in Figure 2. Release of cable 97 will permit shaft 92 to drop to its bottom position as illustrated in Figure 1.

In practice, spring means for biasing the shaft to either one of its two positionsmay be provided and more elaborate means for moving the shaft vertically from one position to the other may be provided. It will be noted that member 96 here illustrated as controlling the movement of shaft 92 is also coupled by cable 98 to chute 90 so that the cement mix supply chute may be moved simultaneously with the shaft. It may be desirable to move chute 90 through a different vertical distance than necessary for shaft 92 and if-this should be necessary, then suitable leverage means may be provided.

Bevel gear 94 is here shown as being journaled in bracket 100 bolted to frame 50. Bracket 100 may journal shaft 92. provide another bearing for shaft 92 in addition to the hearing at bracket 100 so that two spaced bearings for shaft 92 will be provided. These bearings may be spaced a sufficiently great distance along the shaft 92 to insure that the shaft will be amply supported for proper engagement with each of the bevel gears 61 and 86. It is clear that gears 61 and 95 may be replaced by conventional gears rather than bevel gears. The same is true of

gears

86 and 91. Instead of gears, friction members may be used. The gears may be rubber coated metal to minimize wear.

Bevel gear 94 meshes with bevel gear 102 driven by electric motor 103 supported on frame 50. A clutch between the motor and bevel gear 102 may be provided if desired.

When it is desired to move splined shaft 92 to its downward position as illustrated in Figure 1, it will be necessary to have shaft 33 oriented so that

pipes

71 and 72 are cleared by shaft 92 and bevel gear 91. In practice, thevarious parts rotate relatively slowly, of the order of about three or four revolutions per minute, so that the proper positioning of the parts for clearance purposes may be readily obtained.

When it is desired to operate the machine, the various parts are disposed in the position illustrated in Figure 1. Cement mix from a suitable supply is fed by chute 90 to the region within extension 38 of the inner form. At the same time motor 103 is-operated. Windows 80 are open so that cement mix fed to top plate 41 will be distributed In practice, it may be desirable to' f3 by the paddles through the windows to the space between the inner and outerforms. During this operation, vibrators 26 may be energized.

It will be observed that inner form 36 will not be rotating. After sufficient mix has been run into the space between the forms, motor 103 is stopped or suitable clutch means may be provided to stop rotation of shaft 92. Shaft 92 is then moved to its top position so that bevel gear engages gear 61. Inner form 36 is still in the position illustrated in Figure l. Shaft 92 is rotated and drives shaft 33 and inner form 36. Vibrators 26 are still operating. While inner form 36 is being rotated, compressed air to, pipes 72 is provided by suitable valves on the proper hose. This causes shaping ring 83 to be moved downwardly from the position shown in Figure 6 to the position shown in Figure 7. Since the inner form is rotating, shaping ring 83 will also rotate and shape the end of the mix. Excess mix will be forced out through the clearance between angle iron 78 and the top edge 30 of outer form 22.

It is necessary to turn inner form 36 for a few turns, such as about three or four, after which the inner form may be raised. Before elevating the inner form, vibrators 26 are stopped. Preferably inner form 36 is rotated while being elevated until the inner form is clear as'illustrated in Figure 2. At that time, compressed air may be fed to pipe 71 to raise shaping ring 83 to the position illustrated in Figure 6. The drive for shaft 33 is stopped at a proper point so that later shaft 92 and lower gear 94 may go down and mesh with bottom gear 86.

After the inner form has been raised clear of the mix, as illustrated in Figure 2, the outer form with its mix may be removed. The outer form may be opened and separated from the mix. As a rule, the mix is sufliciently dense so that it is a self-supporting mass and may be cured.

Because of the possible wear and tear on the various gears, the various gears may be made of rubber or other material or instead of gears, friction members of rubber may be provided.

The shaping ring illustrated in Figures 6 to 8 inclusive and also shown in Figures 1 and 2 may be dispensed with for certain types of work and instead the modification illustrated in Figure 9 may be used. Thus referring to this figure, inner form 36 carries bolted thereto shaping plough 83'. As many of these may be bolted to the outside of the inner form as are necessary. In practice, only one may be necessary since rotation of the inner form will cause plough 83' to impart the desired shape to the top end of the mix. If this modification is used, shaping ring 83 may be retained in the elevated position as illustrated in Figure 6 so that it is inoperative, or the shaping ring may be removed from annular angle iron 78.

It is not necessary that gears 61 and 86 be similar. The same is true of

gears

95 and 91.

In the form of the invention so far described, means have been provided for 360 rotation of the inner form. While it is possible to provide means for rotating the paddles and means for rotating the inner form so that there will be no conflict due to radiating

pipes

71 and 72, a simple means is illustrated in the modifications shown in Figures 11 and 12 whereby desired movement of the inner form is provided independently of the paddle rotating means. In general, this modification retains the paddle rotating means previously described in connection with Figures 1 to 10 inclusive and provides means for oscillating the inner form through an angle less than 360.

Referring to Figures 11 and 12, the general construction providing for the vertical framework, vertically movable carriage, inner and outer forms, and the bevel gear drive for the paddles is similar to the construction previously described and need not be set forth in detail. Air cylinders 75' in Figures 11 and 12 are provided with vertically spaced

pipes

71 and 72 extending around in a region generallyab ove the top end of the inner form.

gamers

Flexible hoses

95 and 96 may be provided for feeding compressed air to the pipes for the cylinders. It will be noted that shaft 33' in this modification is solid and does not require any piping therein In order to oscillate shaft 33 and the inner form coupled thereto, cross bar 8 is rigidly attached to shaft 33. Cross bar 98 has pivotally secured thereto at opposite ends piston rods int) and 101. Piston rod Tilt) is attached to piston 102 operating in cylinder 193. Piston rod M31 is similarly connected to cooperate with cylinder 1595. Cylinders 103 and 165 are pivotally secured at we and Th7 so that the cylinders may oscillate about a vertical axis perpendicular to the travel of the respective pistons. Cylinder 13 has

flexible hoses

109 and 110 coupled to the opposite ends thereof. Cylinder 105 has fiexible hoses 111 and 112 similarly connected. Hoses T39 and 111 are connected together to pipe 115 while

hoses

110 and 112 are connected together to pipe 116. Pipes H and 116 are connected to two-way valve 118.

Pipes

117 and 119 are also connected to valve 118. Two-way valve 118 is of the rotary type controlled by the position of cross bar 98. The two-way valve is adapted to supply either compressed air or a fluid such as oil under pressure to one side of the pistons in the cylinders and exhaust the region on the other side of the pistons.

Flexible hose 117 is connected to valve 120, adapted to be supplied from pump 121. Hose 119 is connected to the intake of pump 121. Pump 121 may be driven by any suitable means such as by electric motor or gasoline engine and is adapted to maintain a satisfactory pressure of liquid.

Thus for example, referring to cylinder 103, it is clear that in the position illustrated in Figure 12, liquid under pressure will be provided in hose 110 to force piston 102 to the end of its stroke. exhaust the cylinder. Assuming that the end of the stroke een reached, two-way valve 118 will reverse the hose connections. Piston 1435 will operate in a similar manner, both pistons 1133 and 105 being coupled to exert force on the opposite ends of cross bar 98 and thus reciprocate rt e,

ShBLL so The angle through which the shaft and the inner form may be reciprocated will be governed by the piston stroke, the radius arm from shaft 33 to the piston rod. in general, the shaft and inner form may be oscillated over an angle up to as much as 60 if desired. In practice, however an angle of or of travel of the inner form is ample.

Where a continuous annular shaping form similar to 83 in Figure 7 is used, then satisfactory shaping will occur. Where an individual plough 83 such as illustrated in Figure 9 is to be used, then a number of such ploughs angularly spaced around inner form 36 will be required. The number of such separate shaping ploughs will depend upon the angle of oscillation and in general there should be enough shaping ploughs so that the angular range covered by one shaping plough will overlap the angular range covered by the adjacent shaping plough to provide substantially uninterrupted shaping.

Hydraulic pump 121 may also function as a source .5.

of power for winch 123 for operating on cables 57 and S8 for controlling the elevation of carriage A valve will be provided for controlling the winch.

It will be noted that in the modification illustrated in Figures ll and 12, shaft 33 requires no splines and operates within bearing the shaft being adapted to move longitudinally as well as rotate in the bearing.

What is claimed is:

1. Apparatus for casting concrete pipe comprising a horizontal base, means for supporting an outer cylindrical form vertically on said base, a platform, means for supporting said platform so that it may be moved vertically, a vertically disposed shaft carried by said platform, said shaft being rotatable with respect to said platform, an inner form rigidly secured to said shaft,

At the same time, hose 109 will said inner form being coaxial with said outer form and movable from a position within said outer form to a position clear of said outer form, said inner form having a top circular plate forming a cover for said inner form, said top circular plate having a top portion of the inner form extending upwardly above the same, said upwardly extending portion of said inner form having a series of discharge apertures therethrough so that cement mix resting on said top cover plate may be fed through said apertures to the space between the inner and outer form, paddle means rotatable around said shaft and disposed just above said top cover plate to distribute mix to said discharge apertures, means for supplying concrete mix to said top cover plate when said inner form is in its lower position within said outer form, means for rotating said paddles, means for moving said inner form around its axis, vibrating means coupled to said outer form for tamping concrete mix, means for cutting off the feed of concrete mix to the space between said forms when said inner form is being moved, and means supported by said inner form for shaping the top of the mix between said forms.

2. The apparatus according to claim 1 wherein said means for shaping the top end of the mix includes an annular shaping ring disposed around the outside of the inner form near the top end portion thereof, and power means for raising said annular shaping ring clear of the mix or lowering the same down against the mix as desired.

3. The apparatus according to claim 2 wherein said annular shaping ring is attached to an annular angle iron, said angle iron extending around the outer surface of the inner form and having a vertically disposed flange, said angle iron being adapted to close the apertures in the upper portion of said inner form when said angle iron and shaping ring are in the lower position for operating on the mix.

4. The apparatus according to claim 3 wherein the power means for moving said shaping ring and angle iron comprise a plurality of air cylinders carried by said inner plurality form, air pipes extending from said cylinders to the shaft interior and coupling means on the top end of the shaft for establishing connections between stationary and rotatable air pipes.

5. Apparatus for casting concrete pipe comprising a horizontal base, means for supporting an outer cylindrical form vertically on said base, a platform, means for supporting said platform so that it may be moved vertically, a vertically disposed shaft carried by said platform, said shaft being rotatable with respect to said platform, an inner form rigidly secured to said shaft, said inner form being coaxial with said outer form and movable from a position within said outer form to a position clear of said outer form, said inner form having a top circular plate forming a cover for said inner form, said top circular plate having a top portion of the inner form extending upwardly above the same, said upwardly extending portion of said inner form having a series of discharge apertures therethrough so that cement mix resting on said top cover plate may be fed through said apertures to the space between the inner and outer form, paddle means rotatable around said shaft and disposed just above said top cover plate to distribute mix to said discharge apertures, means for supplying concrete mix to said top cover plate when said inner form is in its lower position within said outer form, means for rotating said paddles when said inner form is not rotating, means for rotating said inner form when said paddles are not rotating, vibrating means coupled to said outer form for tamping concrete mix, means for cutting off the feed of concrete mix to the space between said forms when said inner form is being rotated, and means supported by said inner form for shaping the top of the mix between said forms.

6. Apparatus for casting concrete pipe comprising a horizontal base, means for supporting an outer cylindrical form vertically on said base, a platform, means for supporting said platform so that it may be moved vertically, a vertically disposed shaft carried by said platform, said shaft being rotable with respect to said platform, an inner form rigidly secured to said shaft, said inner form being coaxial with the outer form and movable from a position within said outer form to a position clear of said outer form, said inner form having a top circular plate forming a cover for said inner form, said top circular plate having a top portion of the inner form extending upwardly above the same, said upwardly extending portion of said inner form having a series of discharge apertures therethrough so that cement mix resting on said top cover plate may be fed through said apertures to the space between the inner and outer forms, paddle means rotatable around said shaft and disposed just above said top cover plate to distribute mix to said discharge apertures, means for supplying concrete mix to said top cover plate when said inner form is in its lower position within said outer form, means for rotating said paddles about the inner form axis, means for oscillating said inner form about its axis, vibrating means coupled to said outer form for tamping concrete mix, means for cutting off the feed of concrete mix to the space between said forms, and means supported by said inner form for shaping the top of the mix between said forms.

7. Apparatus for casting concrete pipe comprising a horizontal base, means for supporting an outer cylindrical form vertically on said base, a platform, means for supporting said platform so that it may be moved vertically, a vertical shaft rotatively supported by said platform and movable therewith, an inner cylindrical form rigidly secured to said shaft, said inner cylindrical form being coaxial with the outer form and having a top portion formed as a shallow cylindrical region disposed above the top of the casting region between the inner and outer cylindrical forms, said inner form having a series of discharge apertures through the wall thereof located above the top of said casting region, a sleeve disposed about said shaft in the region adjacent the series of apertures, paddles carried by said sleeve to be rotated thereby, said paddles being disposed within said inner form above the top cover plate thereof so that said paddles may sweep concrete mix through said apertures into the space between said forms, means for supplying concrete mix to said region where said paddles operate, a first coupling member attached to said sleeve and adapted to receive power and transmit the same to said sleeve for rotating the paddles, a second coupling member disposed around said vertical shaft and spaced above said first named coupling member, said second coupling member being rotatively coupled to said shaft but being slidable with respect to said shaft, means for maintaining said second coupling member in fixed vertical position so that said vertical shaft may slide up and down with said inner form, a second vertical shaft, means for mounting said second vertical shaft so that it may move vertically, power means for rotating said second vertical shaft, means carried at the two ends of said second vertical shaft for engaging said two coupling members, said second vertical shaft being shorter than the distance between said two coupling members so that said second vertical shaft can drive only one coupling member at an one time, said second vertically disposed shaft being adapted to drive said first named vertical shaft and said inner form when said sec ond coupling member is engaged and to drive said paddles when said first coupling member is engaged, means interlocked with said second vertically disposed shaft for shutting off the supply of cement mix to said paddles when said second vertically disposed shaft is disengaged from said first coupling member and means supported by said inner form for shaping the top of the concrete mix between said two forms.

8. Apparatus for casting concrete pipe comprising a horizontal base, means for supporting an outer cylindrical form vertically on said base, a platform, means for supporting said platform so that it may be moved vertically, a vertical shaft rotatively supported by said platform and movable therewith, an inner cylindrical form rigidly secured to said shaft, said inner cylindrical form being coaxial with the outer form and having a top portion formed as a shallow cylindrical region disposed above the top of the casting region between the inner and outer cylindrical forms, said inner form having a series of discharge apertures through the wall thereof located above the top of said casting region, a sleeve disposed about said shaft in the region adjacent the series of apertures, paddles carried by said sleeve to be rotated thereby, said paddles being disposed within said inner form above the top cover plate thereof so that said paddles may sweep concrete mix through said apertures into the space between said forms, means for supplying concrete mix to said region where said paddles operate, motor means carried by said platform and including power transmitting means for rotating the paddles, and means carried by said platform and including cylinder and piston means with cranks coupled to said vertical shaft for oscillating said shaft over a predetermined angle.

9. The apparatus according to claim 8 wherein a hydraulic pump source of power is provided for the cylinders for oscillating the shaft, said pump source being connected by pipe to the cylinder load and wherein hydraulic motor means for moving said platform are provided, said hydraulic motor means having pipe connections to the same pump source.

References Cited in the file of this patent UNITED STATES PATENTS 1,473,969 Nichols Nov. 13, 1923 1,510,220 Heffer Sept. 30, 1924 1,961,981 Pechstadt June 4, 1934 2,204,020 La Due June 11, 1940 2,585,756 Eschenbrenner Feb. 12, 1952 2,605,533 Hirsh Aug. 5, 1952 2,712,679 Everhart et al. July 12, 1955 2,786,252 Curran Mar. 26, 1957 FOREIGN PATENTS 6,803 Great Britain Mar. 22, 1909 411,852 Great Britain June 12, 1934