US2549686A

US2549686A - Apparatus for the extrusion of pipe

Info

Publication number: US2549686A
Application number: US115974A
Authority: US
Inventors: Julius A Hjulian
Original assignee: Crane Co
Current assignee: Crane Co
Priority date: 1949-09-16
Filing date: 1949-09-16
Publication date: 1951-04-17
Anticipated expiration: 1968-04-17

Description

April 1951 J. A. HJULIAN 2,549,686

APPARATUS FOR THE EXTRUSION 0F PIPES Filed Sept. 16, 1949 2 Sheets-Sheet l INVENTOR.

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APPARATUS FOR THE EXTRUSION 0F PIPES Filed Sept. 16, 1949 2 Sheets-Sheet 2 IN VEN TOR.

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Patentecl'Apr. 17, 1951 APPARATUS FOR, THE EXTRUSION OF PIPE Julius A. Hjulian, Palos Heights, Ill., assignor to Crane 00., Chicago, 111., a corporation of Illinois Application September 16, 1949, Serial No. 115,974

This invention relates to a new and improved apparatus for the compression and extrusion of flowable materials and more particularly to apparatus adapted for the manufacture of cement asbestos pipe or other continuous forms made from a cement asbestos mixture or similar material.

In the manufacture of cement asbestos pipe or the like, the basic material used is a fluid slurry comprising mainly cement, asbestos fibres and water. It will be understood that additional ingredients may be used if desired such, for example, as coloring materials, materials for rendering the product more waterproof or materials adapted to accelerate the setting of the cement. Another constituent of. the slurry is a small percentage of entrained air which becomes entrained in the material during the mixing of the slurry.

In order to make a hard and dense product, it is necessary to eliminate the major portion of the entrained air anda substantial portion of the water content of the slurry.

It is an object of the present invention to provide new and improved apparatus for the extrusion of cement asbestos pipe or the like.

It is a further object to provide apparatus of this character which is mechanically operated and extrudes the product by a pulsating or intermittent pressure.

It is also an object to provide apparatus which eliminates substantial portions of air and water entrained in the slurry while minimizing loss of solids suspended in the water.

It is another object to provide apparatus for v extrusion of a continuous length of the product while providing adequate resistance to said extrusion throughout the process so that the product is properly compacted.

It is an additional object to provide apparatus in which. additional slurry is fed into the compression chamber between the intermittent compression cycles of the operation.

It is a further object to provide apparatus which is simple in design and construction and adapted for commercial production and use.

Other and further objects will appear as the description proceeds.

I have shown certain preferred embodiments of the invention in the accompanying drawings, in which- V Figure 1 is a vertical section, partly in elevation, showing somewhat diagrammatically the elements of the apparatus;

Figure 2 is an enlarged section taken on line 2--2 of Figure l;

Figure 3 is a fragmentary view, partly in section, showing a modified form of construction;

Figure 4 is a cross-section taken on line 44 of Figure 3; and

Figure 5 is a fragmentary diagrammatic showing of abrake control system. c

. 5 Claims. (eras-) pressure chamber ll.

As shown in the drawings, the apparatus com"- prises a tubular compression chamber ll into the left end of which is fitted a cylindrical pressure member or piston [2. This member l2 is shown as secured to a slide l3 which is limited to a linear movement by the guides indicated at M. The slide l3 has a connecting pivot pin at l 6 upon which is pivoted a pitman H8. The pitman I8 is fitted on an eccentric crank 20, which crank is carried by a shaft 22. The shaft 22 is carried in the heavy bearing member 24, and this shaft is driven by any suitable power producing or transmitting apparatus. The compression member I2 is shownas connected by rod 25 to a piston head 26; This piston head 26 has the cup-shaped washers 28 secured to its opposite faces by plates 29, these plates being held in position by bolts 30,

The mandrel 33 is supported axially in the compression chamber H from the reduced forward section 34 of the mandrel, which portion has spaced legs 36 secured to the inner face of the An axial bore 38 extends through the center of the member 34 and communicates with the radial bore 39 extending through a lower supporting leg 40. This bore 38 connects with a drain pipe 42 which may be connected to a sump for receiving fluid and air forced or drawn from the pressure chamber. It is to be understood that the pipe 42 may communicate with a source of suction or reduced pressure, which Will assist in withdrawing the fluid and air,

The mandrel 33 is provided with a section 44 for withdrawing the fluid and air. This section 34 contains a number of narrow slits which communicate with the tubular drain passage 38. The particular construction of this drain section forms no part of the present invention and is fully disclosed in my co-pending application, Serial No. 101,346, filed June 25,1949.

A slurry support sleeve 4'! isshown fitted between the inner wall of the pressure chamber ll and the mandrel 33. This sleeve is used only in the start of operation of the apparatus, as will be explained hereafter.

A separate support dscarried by a frame mem ber 50 is provided adjacent the open end of the pressure chamber H to receive the pipe as it is extruded from the pressure chamber. It will be understood that this support 49 may be of any desired length.

A slurrysupply chamber 52 is connected by lower conical section 53 to tubular section 54, this section 54 discharging into the pressure chamber ll adjacent thereduced section 34 of the man drel. A valve seat 56 is provided surrounding the opening 54 into the pressure chamber to ac' commodate a valve 5'11 which is carried byvalve stem 58. Valve stem 58 is guided inspider 59 carried in the chamber 52. A compression spring? 58 is fitted aroundthe valve stem 58, its lower 3 end bearing on spider 59 and its upper end engaging va disc 52 secured to the valve stem. The upper end of the valve stem 58 is shown as provided with a knob 53 for manual operation. A cup 65 for providin lubricant is shown secured to the left end of pressure chamber 1 l and communicating through bore 66 with the inner face of the chamber adjacent the outer surfaceof the pressure piston member l2.

The form of construction shown in Figure 1 is provided with an adjustable brake at the right end of the mandrel. This brake comprises a central cone 75 connected by neck H to the end of the mandrel 33. The free end of the cone has a threaded extension 34 upon which is fitted the bearing washer 75 which is adjusted by nut it. A plurality of cam sectors 7! are fitted about the cone 19, being held against the cone by an expansible sleeve 19. This sleeve 79 may be formed of rubber or other stretchable material having a suitable frictional surface upon its outer face. As shown in Figure l, at the start of operations this sleeve '19 engages the inner face of the slurry support sleeve 47.

The form of construction shown in Figures 3 to inclusive is generally similar to the construction of Figures 1 and 2 except for the additon of a power actuated brake carried by the wall Bl of the compression chamber. The brake comprises a plurality of radially reciprocatin shoes 83, which are normally held in their outer positions by the springs 84 fitted about the studs 85 and bearing against the nuts 86 and the bottom of the recesses 88. Each shoe 83 is provided with a floating operating piston 9|], the piston pressing against a ball 91 which fits in a recess in the outer face of the shoe 83. Each piston 90 is provided with a cup-shaped washer 93 on its outer face, this washer being held in place by a plate 94 and bolts 96.

The pipe 98 introduces fluid under pressure into the brake assembly and into a chamber I03 which communicates by passages I92 with similar chambers HM behind the several pistons 90. It will be understood that these chambers H34 are similarly connected to another such chamber for operating the upper brake shoe shown in Figure 4.

An automatic system of brake operation control has been shown diagrammatically in Figure 5. The fluid supply pipe 98, connected to the brake operating chambers, is supplied with fluid under pressure, such as compressed air, through a rotary valve 86. In one position of the valve, the pipe 98 is connected to a supply pipe l0! while, in the other position, it is connected to an exhaust pipe Hit. The valve m6 is operated by the two solenoids Hi and H2 which are controlled by switches H3 and H4. These switches are shown as actuated by the lugs II? and H55 on the slide rod 125. This slide rod I may be connected to the drive mechanism in any desired manner so that it reciprocates with the piston rod and piston 26.

In the operation of either form of the apparatus to produce extruded pipe, the slurry chamber 52 is supplied with a slurry consisting of water, cement asbestos and other ingredients as desired. It will be understood that the valve 51 is normally closed by means of spring 68. The support sleeve 4'. is introduced into the right end of the pressure chamber around the mandrel to the position shown in the drawings. The apparatus is then placed in operation, the pressure cylinder I2 and piston head 26 being reciprocated from right to left as shown. A movement of the piston to the left reates a reduced pressure in the pressure chamber and this serves to open the valve 5'! and pull the slurry into the chamber. As the piston moves to the right, material in the chamber is compressed. This compression is resisted by the support sleeve 41, which is frictionally held by the grip of the expansible sleeve 19 as shown in Figure 1. As the reciprocations continue, the pressure chamber is filled and, as the material is compressed, the sleeve 47 is gradually forced to the right. As this sleeve uncovers the slits in the water-removing portion 44 of the mandrel, the pressure forces water and entrained air through these slits. As previously stated, the Withdrawal'of this water and air may be facilitated by creating a suction within the water-removing section.

As the operation of the apparatus continues, the support sleeve 41 is forced from the right end of the chamber and from the mandrel and is followed by the formed pipe. The formed section of pipe takes the place of the support sleeve in that its frictional engagement with the mandrel and pressure chamber wall causes it to resist the pressure strokes of the piston, thus causing the compression of the material as it is added to the forming pipe by each stroke of the apparatus. Additional friction may or may not be applied to the pipe by the expansible sleeve 79. If it is not desired to apply frictional pressure to the pipe, the nut 15 may be backed away as soon as the sleeve 41 clears the sleeve 19 so that the sleeve 19 contracts and permits the formed pipe to slide over it.

In the form of construction shown in Figures 3 to 5, the brake shoe 83 frictionally grip the support sleeve 4'! when air or other fluid under pressure is admitted to the chambers behind the pistons $6. By the form of control shown, this pressure is applied to the brakes during the forward or forming stroke of the piston 26. Immediately upon the start of the reverse movement of the piston 26, the brake pressure is released. This permits the formed pipe to move to the right for a short distance under the influence of the residual pressure in the slurry before the piston 26 moves far enough to remove all pressure. While the main constituents of the slurry are not compressible, it contains a percentage of entrained air which is compressed and tends to expand as the piston starts back. This is an important factor in the movement of the formed pipe.

It will be apparent that the slurry chamber 52 may be supplied with the slurry when necessary, and that the operation may be continuous and pipes produced in any desired lengths. It will also be apparent that the relative shapes of the mandrel and compression chamber may be varied so that shapes other than circular tubular pipe may be produced by the form of apparatus shown. The length of coacting surfaces of the pressure chamber and the mandrel may be varied, if desired, so as to afford greater or less frictional resistance to the movement of the forming pipe. This frictional resistance co0p erates with the braking action of the different forms of brakes shown to provide greater or less compression in the finished product.

While I have shown and described certain preferred forms of construction, these are to be understood as illustrative only as the apparatus may be modified to meet differing conditions and requirements, and I contemplate such variations as come within the spirit and scope of the appended claims.

I claim:

1. Apparatus for the extrusion of pipe or the like from a water carrying slurry, comprising a pressure chamber having open ends, a pressure piston fitted into one end of the chamber, means for reciprocating the piston, the wall of the pressure chamber having an opening therein spaced from the inner limit of piston movement, means for supplying slurry through said opening, a-mandrel located within said chamber and supported by means connecting the mandrel to the inner walls of the pressure chamber, and a movable support sleeve fitted between the mandrel and inner wall of the pressure chamber, and braking means adapted to engage the support sleeve to restrain it against movement.

2. Apparatus for the extrusion of pipe or'the like from a water carrying'slurry, comprising a pressure chamber having open ends, a pressure piston fitted into one end of the chamber, means for reciprocating the piston, means for supplying slurry to the chamber in advance of the piston, means for withdrawing fluid from the chamber, and adjustable movable members internally of the chamber for restraining movement of the dewatered slurry from the end of the chamber opposite the piston.

3. Apparatus for the extrusion of pipe orthe like from a water carrying slurry, comprising a pressure chamber having open ends, 'a pressure piston fitted into one end of the chamber, means for reciprocating the piston, means for supplying slurry to the chamber in advance of the piston, means for Withdrawing fluid from the chamber, a mandrel in the chamber and expansible means carried by the mandrel for gripping the dewatered slurry and restraining movement thereof from the end of the chamber opposite the piston.

4. Apparatus for the extrusion of pipe or the like from a water carrying slurry, comprising a pressure chamber having open ends, a pressure piston fitted into one end ofthe chamber, means for reciprocating the piston, means for supplying slurry to the chamber in advance of the piston, means for withdrawing fluid from the chamber, a brake carried by the chamber walls, said brake being normally inoperative, and means for selectively moving the brake to gripping position upon the contents of the chamber to restrain-movement thereof from the end of the chamber opposite the piston.

5. Apparatus for the extrusion of pipe or the like from a water carrying slurry, comprising a pressure chamber having open ends, a, pressure piston fitted into one end of the chamber, means for reciprocating the piston, meansfor supplying slurry to the chamber in advance of the piston, means for withdrawing fluid from the chamber, a fluid operated brake carried by the chamber walls, means for supplying fluid under pressure to operate the brake to grip material in the chamber, and means for controlling the .flow of the fluid to the brake, said control means being operatively associated with the pressure piston to coordinate brake action with piston movement.

JULIUS A. HJULIAN.

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

UNITED STATES PATENTS