US1736793A - Pipe-making machine - Google Patents

Description

Nov. 26, 1929. e. c. MARTIN PIPE MAKING MACHINE Filed Oct. 26, 1926 Patented Nov. 26, 1929 siren STATES GEORGE C. MARTIN, OF LOS ANGELES, CALIFORNIA PIPE-MAKING MAGHIN E Application filed October 26, 1926. Serial No. 144,263.

This invention relates to pipe-making machines, particularly to that class of pipe-making machine adapted to rapidly form pipe of concrete and like materials. The machine 5 about to be described will densely pack the pipe-making material throughout the length of the pipe. This is particularly important because the pipe ends often differ as to form. Some pipes are belleended, while others may have different forms of flanged ends, and it is sometimes a difiicult matter to properly form such ends. The present machine about to be described will manufacture straight-sided or so-called tongue and groove pipe as sat- 5 isfactorily as it will form bell-ended pipe.

Furthermore, the present invention can be adapted to specifications and requirements in the making of pipe. For instance, certain specifications may require that the pipe ends whether of the tongue and groove type or bell-end type should be not too dense in na ture, all to the end that cement and like material may readily secure a hold in the interstices of such ends. On the other hand, the requirement may be that such ends be closely packed so as not to readily permit water to seep therethrough. Regardless of the require ment, the present machine will accommodate itself to any specification in the making of a pipe. If a bell-ended pipe is to be formed it is customary to provide an outer mold having a bell form at one end and an inner mold with a packer head for forcing the cement concrete or other material into the pipe mold. If we start at the bell-end and rapidly rotate the packer head, at the same time pouring the cement, concrete or the like into the mold, the packer head if it rotates at a constant rotative speed will so rapidly act upon the plastic material that the plastic material practically bridges the gap between the molds and does not properly form the bell-end. In this particular it is similar to a high speed propeller, in that any material striking the same would be thrown directly outwardly with great force, and this is exactly what occurs in pipe-making machines where the packer head is rotated at a constant speed during the making of the entire pipe. A packer head consists in the present invention of propellers or wings mounted above trowelers and with a casing known as a smoothing cylinder immediately below the trowelers. These three members constitute the packer head and are mounted upon a shaft which is adapted to reciprocate and rotate. When the plastic material is poured within the outer mold to be acted upon by the wings which force the plastic material outwardly between the molds, the said casing forming one of said molds, what- 60 ever plastic material, drops between the wings is immediately sent outwardly with great force against the inner surface of the outer mold. If, now, the packer head is rotated at its usual'rotative speed of 200 revolutions per minute or over, very little of the plastic material would fall by gravity between the wings or propellers, and that which did fall therebetween would be so forcibly moved outwardly from said wings as to prac- 7 tically bridge any gap that might exist between the inner moldand the outer mold, with the consequence that the end of the pipe would not be properly formed, or if formed at all under ordinary circumstances, would be of little strength and density. Using'the same rotative speed for the packer head throughout the making of the length of pipe it takes approximately as much time to form the end of the pipe as it does to form the entire body of the pipe. In other words, the body of the pipe is formed in some twelve to fourteen seconds.

My invention has for an object the overcoming of the difficulties above enumerated and 85, to provide a pipe of great strength through out its length, and likewiseprovide a pipe having any density desired.

Another object is the provision of a device for forming pipe from plastic material which is simple of construction, superior in operation, economical, and highly eflicient in use and service.

With the above and other objects in view, the invention consists in the novel and useful provision, formation, construction, association and relative arrangement of parts, members and features, as well as. a method and process of use, all as shown in acertain embodiment in the accompanying drawing, de-

is a packer head, I) anouter inoldmembe'r, c

means f r ren g th realm ead Flemin for varying the S368l of rotationbf the means 0, and 6 means for raising and-lowering r st r e d, l o which e en s may be utilized in practicing an embodiment of the invention 7 More particularly the device A in the present instance includes frame-work 1 mounted upon a suitable base 2, which frame-work is adapted to carry the various elements enterinto the invention, Thebase 2 is adapted to support a rotatable turn-table 3 provided with annular flange members 4, which flange members accommodate and pesitienthe outer mold b as well as an inner mold f. The base 2 is provided with rollers 5 whereby the turntable may be readily rotated to any desired position by graspinga handle 6. The packer head a is mounted on a shaft 7, in the present instance the shaft being squared, and which shaft is passed through bearings 8 and 9,, and into a cylinder 10, where it connects with a piston. A. beveled gear 11 forming a part of the means c is mounted above the hearing 8 and is carried uponthe shaft '7 whereby rotation of said gear would produce rotation of the said shaft. i

The 6 includes source of fir-aid supply which in the present instance would be contained in a chamber member 12 with pipes 13 and 14 communicating with said chamber member and the fluid therein, and another pipe 15 communicating with said chamber member and with a pump 16. A pipe 17 leads from pump and .to thecylin'der 10 at one end of said cylinder, as shown at 18, while the pipe'l3 leads to the topof the cylinder at 19. The exact operation of -the means 6 will not be detailed at, present;

The upperend of the shaft 7 may or may not hesquared after it leaves thecylinder 10. Howeyer, said: upper end of theshaft carries a cross yoke 20 formed with, end guides 21, th rc be ng a pair of standards 22 passed t rough sa 1- end guides and with the said standards fastened to the framing 1. Thus as theshaft 7V is raised by the means 6 the cross yeke and the standardsQQ will hold the said shaft rigidly and prevent side move he eet The drawing of Fig. 1 shows that the outer mold b is provided wit-h what may be termed a bell-end 23. The opposite end of said mold is straight as shown at 24 and is adapted to carry a hopper 25, which hopper is formed with a mold portion 26 for forming an inner flange on. the pipe-making material. In order to form the bell-end, the mold f is like wise provided and which mold is substantially an annulus the periphery of which is formed with a base portion 27, an inclined side wall 28, and a top wall 29 substantially paralleling the bottom wall. In the present instance an, inner annular wall 30 joins the top tan The packer head a includes wings 31, trowelers 32, and a casing 33. The casing is substantially an annulus and acts to smooth the inside of the material forming the pipe. This casing is provided witha casting 34, which casting is secured to the shaft 7 The trowelers 32, of which there is a pair in the present instance, are secured to a spider, which spider is likewise secured to the T, and the said wings L are secured by belts or otherwise to the spider. Each of the trowelers, as may be seen from inspection of the drawing, is provided with a wiping edge or troweling edge 36. In other words, the trowelers may be described best by saying that the wiping edge 36 thereof has a constant contact surface working against the inner wall of the pipe during its formation and with a receding wall leading from said wiping edge, which has a constantly changing radius, as the drawing indicates. The wings 31 may be termed propellers in that they will act upon any plastic materialpoured within the outer mold to force said plastic material against said outer mold during the formation of the plastic material into pipe form.

The means 0 includes a shaft 37 carrying a bevel gear 38 which meshes with the gear 11, and the said shaft is conveniently carried in bearings in theframework 1. It will be noted thatfa standard 39 is secured to top and bottom portions of the framework 1 and that said standard is provided with a bearing portion 40 within which portion is received an end of the shaft 37. Loosely mounted and carried upon the shaft 3'? are pulley wheels 41 and 42 respectively. Spaced from the shaft 37 is a shaft 43 suitably j-ournaled in bearings 44 and 45 respectively, carried by the framework 1 into standard 39. Mounted upon the shaft 43 are a pair of pulley wheels 46 and 47, respectively; the pulley wheels 42 and 46 are of small diameter, and the pulley wheels 41 and 4'? are of larger diameter with respect to the pulley wheels just mentioned. A continuous belt 48' is passed between the pulley wheels 41 and 46, and a continuous belt 49 between the pulley wheels 42 and 47. Such shaft 43 likewise carries a ve Pul1ey5 nd wh d ve p l ey would be associated with any drive belt communicating with a source of motive power. A clutch g is associated with the drive shaft 37 and such clutch is of the saw-tooth type, and includes saw- tooth plates 51 and 52 secured to the pulley wheels 41 and 42 respectively, with a shiftable saw-toothed member 53, keyed to the shaft 37 and adapted to engage one or the other of the plates 51 or 52. This shifting of the member 53 is accomplished by means it constituting a lever 54 provided with a forked end for engaging the member 53, and which lever is pivoted at 55 to an extension 56 upon the standard 39. The end of the lever opposite the forked end is connected to a link 57 which link in turn connects to an end of a bell-crank lever 58, which bell-crank lever is pivoted to the standard at 59. The opposite lever of said bell-crank has a link 60 secured thereto, which link 60 has a handhold 61. Pulling downwardly upon the link 60 will cause the member 53 to engage the teeth of the member 51, while pushing upwardly upon the link 60 will cause the member 53 to engage the teeth of the plate 52.

Mounted upon the shaft 43 is a sprocket wheel 62 and the pump 16 is driven by a shaft 63, which shaft carries a sprocket wheel 64. A continuous chain 65 is passed over and between the said sprocket wheels 62 and 64. The operation of the device is as follows: The link 60 is pushed upwardly to the position where the shiftable member 53 is out of engagement with either of the plates 51 or 52. Assume that the drive pulley 50 is being rapidly turned, which would of course rotate the shaft 43. Upon pulling downwardly upon the link 60 the shiftable member 53 would engage the plate 51 and rotation of the shaft 37 would occur. The rotation of said shaft, however, would be at a considerably lesser rate than the rate of rotation of the shaft 43, due to the difference in diameter between the pulleys 41 and 46 respectively. The shaft 7 is first lowered so that the packer head will be at its lowest operating position and this is conveniently done by opening a valve 66 in the by-pass line 14, which line by-passes any liquid within the lower portion of the cylinders 10 back into the compartment member 12. During this time the packer head 1s rotating at a determined rotative speed, say fifty revolutions per minute. The plastic material for forming the pipe which may be concrete aggregate of water, hydraulic cement, sand, broken rock and the like, is poured into the hopper 25 and drops from said hopper by gravity within the outer mold b and contacts with the packer head a. Due to the fact that the packer head is rotating comparatively slowly, the plastic material is able to fall between the space included between the two wings 31, whereby the wings will act upon said material and force the same outwardly and downwardly. The shaft 7 is not elevated until the bell is properly filled with the plastic material, and which plastic material is being acted upon at slow rotative speed by the packer head. After the bell-end is properly filledthe member 53 of the clutch is shifted so that the shaft will commence rotating at a high speed. It is necessary that the high speed be obtained in the packer head in order that the material be tightly packed. When the high speed rotation is commenced the valve 66 is opened to pump oil or other material back of the pistons in the cylinders 10 in order to slowly elevate the packer head, and this opening of the valve will also permit the oil to by-pass above said pistons back through the pipe 13 to the chamber member 12.

This slow rotation permits the packer head and the troweling head'to properly act upon the plastic material in such a manner as to permit the plastic material to be directed into the space included between the curved end of the outer mold and the inner mold f, and thus properly form the bell-end. As illustrative of what is accomplished, the plastic material has an opportunity to fall and likewise be driven into the space included between the mold f and the bell-end of the mold b. If the packer head were driven at a high speed, say two hundred revolutions per minute or over, a minuteportion of the plastic material would fall between the wings 31, and this minute portion would be driven outwardly by said wings with great force. The efiect'of this action would be to build up a bridge at the zone marked 70, which would make it im possible or extremely difficult to force the plastic material, either through action of the wings or the trowelers 32 in a compact mix as far down as the base member 27 of the mold f. That material which would fall down to this point would be of loose formation and of practically no strength.

In order tomake pipe properly as far as the body of the pipe is concerned, actual eX- perience has taught that the packing mechanism must rotate at a relatively high rate of speed and that this speed is measured more as a peripheral than as a rotative speed, and

as has been previously pointed out it takes practically twelve to fourteen seconds to make the body of the pipe, this being because the pipe-making material is driven directly out wardly with great force by the wings. If the packer head were to be rotated slowly at all times during the making of the pipe, it would be necessary as far as the body portion was concerned, to raise the packer head at greater speed between each revolution and the extent of lift between each rotation would be more than is desirable in the making of good pipe. It has been found from experience that it is most practical to have one complete rotation of the packer head for about each one-quarter inch ofrise. Thus if the trowelers 32 are two inches wide, and the packer head is raised one-quarter inch at each revolution thereof, each particle of pipe is troweled eight times. It is this excessive troweling which has the effect, first, of making dense pipe, and second of pulling a little water out of the mix to the surface of the pipe.- WVith this water comes a little cement. The eifect of this water and cement is to reduce the friction of the packer head parts and to leave a thin skin of material, rich in cement, on the inside of the pipe.

Thus in the making of the pipe the packer head will first be run at a slow speed until the bell-end is filled, and the wings 31 are crowded or packed full of the pipe-making material, whereupon the link 60 is pushed upwardly to shift the clutch and cause a more rapid rotation'of the shaft 37, and as a consequence more rapid rotation of the shaft 7 with its packer head.

In Fig. 2 an ordinary form of tongue and groove type of mold is provided in the rotary turn-table 3, and the shaft 7 would be rotated at differential speeds as before.

I do not Wish to confine this invention to the making of bell-endpipe alone, as it is adaptable for the making of any form of pipe regardless of the shape of the ends thereof. Furthermore, I do not wish to be confined to the change speed mechanism illustrated in the drawing, as other forms" of change speed mechanism may be utilized such as a planetary type of transmission on the drive shaft 37. Furthermore, it is not especially important where the chain speed device is'placed exceptv that it must be somewhere between the motive power and the packer head. It is obvious that various changes and modifications and variations may be made in practicing the in vention, in departure from the particular showing of the drawing and the description as given without departing from the truev spirit of the invention.

Having thus disclosed my invention, I claim and desire to secure by Letters Patent:

1. In a machine for making pipe from plastic material which subsequently liar-dens, a mold, a packer head rotatably supported and longitudinally movable within said mold, and having a troweling portion, and means for imparting variable speed rotation to said packer head whereby the preliminary rota tional speed of the packer head will be less than the subsequent speed thereof.

2(In a machine for making bell-end pipe from plastic materialfwhich subsequently hardens, comprising a mold having a bellend, a packer head having troweling means:

thereon, means for moving the packer head longitudinally through the mold, and means for rotating the packer head during said 1on gitudinal movement, said means including manually shiftable change speed gearing for causing relatively slow rotation of the packerhead while it is operating on the plas tic material in the zone of thebell of the mold, and then causing a rapid rotation of the packer head as it proceeds toward the opposite end of the mold.

3. In a machine for making bell-end pipe from plastic material. which subsequently hard-ens, comprising a mold having a bellend, a packer head having troweling means thereon, means for moving the packer head longitudinally through the mold, means for rotating the packer head at a slow speed and means for rotating the packer head at a faster. speed during its longitudinal movement. y

In testimony whereof, I name to this specification.

have signed my I] ii

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