US1971088A

US1971088A - Apparatus for centrifugally molding concrete pipes and other tubular bodies

Info

Publication number: US1971088A
Application number: US625071A
Authority: US
Inventors: Williams Ralph
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-09-17
Filing date: 1932-07-27
Publication date: 1934-08-21
Anticipated expiration: 1951-08-21

Description

Aug. 21, 1934. R. WILLIAMS APPARATUS ROR CENTRIFUGALLY MOLDING CONCRETE PIPES AND OTHER TUBULAR BODIES Filed July 27, 1952 Patented Aug. 21, 1934 Unire 'stares' tries 'APPARATUS FORA CENTRIFUGALLY MOLD- ENG CNCRETE PIPES AND OTHER TUBU- LAR BDHES Ralph Williams, Sydney, New South Wales,

Australia Application July 27, 1932, Serial No. 625,071 lin Australia September 17, 1931 2 claims. (oies-.30)

This invention relates to improved centrifugal molding apparatus for the manufacture oi concrete pipes. and other tubular bodies in which molds containing concrete or like plastic cern action is applied to the concreteV or other material` in the molds so that the pipes or other articles produced are particularly dense in character and are :free from air bubbles and voids or cavities. f

Another object of the invention is to provide centrifugal molding apparatus in which generally the manufacture of concrete pipes may be more expeditiously effected, and in which special detachable molds are charged with cemn entitious material before they are inserted into a rotatable carrier to mold the contained mam terial into the required form. A

A further object resides in the provision of centrifugal molding apparatus in which the `mold carrier is mounted on adjustable antifriction bearing rollers and is adapted'to receive interchangeable holders for detachable molds of diierent sizes, and in which a' brake is provided to quickly arrest the rotation of the mold. carrier when required.

The invention also provides an improved pipe mold adapted to be Yreadily placed in and driven by the rotatable mold carrier and provided with a detachable former shaped to correspond with the interior oi a pipe faucet.

In the accompanying explanatory drawlngi- Fig. 1 is a side elevation of centrifugal molding apparatus according to Vthe invention.

Fig. 2 is an end elevation of the molding apparatus.

Fig. 3 is a transverse section of the molding apparatus.

Fig. 4 is a sectional View of a detail.

Fig. 5 is a transverse section of4 the antifriction bearing roller seen in Fig. fi.'

Fig. 6 isa view partly in elevation and partly insection of a pipe mold.

Fig. '7 is a section of portion of a modiiied pipe mold. p

In the drawing, 1 indicates a base or bed plate upon which are iXed axially aligned hollowbearing housings 2. These bearing housings are preferably made in two parts, the lower part 3 being bolted to the base or bed plate 1, and the upper part 4 being detachably secured to the lower part 3 by bolts rllhe bolts 5 are passed through franges c and 7 ormed respectively on the upper and lower parts of the housings 2, and removableshims or liners 3 may be inserted between the flanges 6 and i so that the parts 3 and Il of the housings may be brought more or lessclosely together.

The bearing housings 2 are of trough-shape or section-see Fig. 4-and mounted on spindles or bolts 9 extending `transversely through the housings 2 are vanti-friction rollers 10 fitted with' ball bearings as shown, or with roller bearings or other type of suitable antiefriction bearings.

The ball bearing rollers l0 are evenly spaced at equal radial distances from the axis oi the bearing housings 2 and their inner races 11 are eccentricaliy mounted upon the spindles or bolts 9 and are non-turnably fixed to the same as by keys i2; see Fig. 5. Accordingly, it will be observed thatby turning theY spindles or bolts 9v the rollers 10 can be adjusted towards or away from the axis of the housings 2 forV a purpose hereinafter referred to. The anti-friction rollers 1G Vare maintained in a central position in theV bearing housings 2 by collars 13 mounted upon thespindles or bolts 9.

The outer races 14 of the ball bearing rollers lo are encircled with annular hardened wearing bands 15 which iit and roll inv peripheral grooves 16 in annular bearing rings 17. These annular bearing rings rit ireelyvin the bearing housings 2 and are disposed peripherally about and fixed to` a tubular mold carrier 18.

`1n Figs. 2 and 3, three anti-friction rollers 10` are shown, the same being evenly disposed about the mold Vcarrier 18, butv a greater number of said rollers may be used if required. However, it will be understood that if less than three anti'- iriction rollers 10 are employed it will not be possible to avoid slackness oi the rotatable mold carrier 1S or to spin the same at high speed.v

The interior oi the Vmold carrier 18 is provided with mold supports or holders 19 which are bored at 20 to accommodate and accurately centre a. mold 21, see Fig. 3. The supports or holders 19 maybe conveniently formed as east ings, and they may be detachable andy nter# changeable -with othersof various sizes, so that molds of greater or less dimensions may beI readily accommodated'in the mold carrier 18.A

` The mold 21 (shown separately in Figs. 6 and 7) is preferably made in two semi-cylindrical portions or

halves

22 and 23 havingangle strips 24 Xed along their edges. The two halves or semi-cylindrical'portions 22 and 23 are'secured together to formthe mold 21 by bolts 25 passing through the adjoining angle strips 24.

In order to permit the mold 21 to be inserted into the mold carrier 18 and to provide a driving connection between the latter and the former,

loo

rot

the holders or castings 19 are provided With opposed radial slots 26. These radial slots accommodate the angle strips 24, and the edges of said slots by contact with the angle strips provide a positive driving connection between the mold carrier 18 and the mold 21 and prevent independent rotation of the latter and the former.

The mold 21 at one end may be provided'with an angle ring or internal nan-ge 2'7 forming a circular opening 28 of somewhat less diameter than the interior of the mold 21.

The opposite end of the mold 21 may be provided with an enlargement 29 shaped to correspond with the external contour of a pipe faucet. Detachably tting the exterior of the enlargement 29 is an annular member or former 30 shaped to form the interior of the pipe faucet.

The annular member 30 may be secured to the enlargement 29 by a bayonet Vslot 31 made in the former and adapted for engagement with a projecting pin 32 xed in the latter. Alternatively, the detachable annular former 30 may be xed to the enlargement 29 by wing nuts 33 or other suitable fastenings.

In practice, the two

halves

22 and 23 oi the mold 2l are oiled and assembled by the bolts 25, and the mold is then placed on end with the faucet enlargement 29 downwards, the annular former 30 being suitably plugged. Suiiicient concrete or other cementitious material to form a pipe of required thickness is then placed in the mold 21 and the opening 28 is suitably plugged. The charged mold 21 is then placed in position in the mold carrier 18, and the latter is set in rotation, preferably by a driving belt 34 applied to its periphery.

The mold carrier 18 with the mold 21 therein is then slowly rotated for a short period to enable the concrete to become evenly distributed over the inner surface of the mold. The speed is then increased and the mold 21 is rotated for a suflicient time at nigh speed to consolidate the concrete material.

Trowelling means of well-known construction is quickly run over the interior of the pipe during the formation to withdraw the water and slurry separated by the compacting centrifugal action and to render the surface of the finished pipe hard and smooth.

A brake is provided toy enable the rapidly rotating mold carrier 18, mold 21 and the pipe therein to be quickly brought to rest, when required. The brake may be oi anyk suitable construction and hand or foot operated, and it may comprise a post 35 Xed to the base 1 and prou vided with a lever 36 and brake shoe 37 to be applied to the periphery of the mold carrier 18 by manual operation.

The interior of the bearing housings 2 may be subdivided into chambers 38 by transverse partitions 39 positioned `adjacently to and on opposite sides of the anti-friction rollers 10. The said chambers 38 may be packed with suitable semi-iluid lubricant and, theyrmay be provided with lubricatingqdevices e0. Accordingly, the anti-friction rollers 1G and the annular bearing rings 17 are at all times efficiently lubricated, thereby ensuring silent and smooth operation and minimizing wear. i v

At the conclusion of the spinning operation, the mold carrier 18 is stoppedby the brake shoe 37, and the mold 21Vis removedand set aside ,for

a sufficient time to permit the concrete material to properly set and harden. The annular faucet member or former 30 is then removed and the bolts 25 are withdrawn, thereby permitting the

semi-cylindrical portions

22 and 23 to be taken from the finished pipe.

Owing to the high speed made possible by the anti-friction rollers 10 and the eiiicient lubrication, the iinished pipe is very dense, smooth and hard. Moreover, it may be readily removed from the mold 21 without steaming, and generally in about live hours after the termination of the spinning operation, thereby permitting the molds 21 to be used twice daily.

The adjustable feature of the ball bearing rollers l previously described enables the mold carrier 18 to be accurately centered in each of the bearing housings 2, so that it may spin with minimum frictional resistance and without shake or looseness. Moreover, by adjustment of the rollers 10 and removal of one or more of the linersor shims between the lower part 3 and the upper part 4 of the bearing housings 2, wear of the rollers 10 and annular rings 17 may be compensated for and correct alignment of the mold carrier 18 and bearing housings 2 may be permanently maintained.

It will be understood that as the concrete material is placed in the mold 21 before the commencement of the spinning operation, the undesirable reduction of the water content brought about when the material is thrown in shovelfuls into the rotating mold is obviated.

What 1` do claim is:-

1. A centrifugal molding apparatus including a base, a plurality of two-part annular housings carried by the base, one part of each of said housings being Xed to the base, the remaining part of each of said housings being adjustably connected to the fixed part, ball bearing supports mounted in the respective parts of each housing, a mold carrier arranged within each housing and rotatably supported on the ball bearing supports therein, one of said ball bearing supports being ecoentrically mounted for adjustment toward and from the mold carrier, each ball bearing support including an annular member removably mounted on the ball bearing support and forming the bearing for direct contact with the mold carrier, and an element on the mold carrier disposed in an open inner periphery of each annular housing to provide bearing contact with the removable member of the ball bearing.

2. A centrifugal molding apparatus including` a base, a rotating mold carrier, an annular housing encircling the carrier adjacent each end thereof, each housing comprising a part xed to the base and a second part adjustably connected to the IiXed part, the parts of the housing being formed with chambers opening toward the carrier, a ball bearing in each of said chambers, means for eccentrically mounting atleast one of said ball bearings to provide for its adjustment toward and from the carrier, said ball bearings including an annular separable member formling the contacting element between the bearing and carrier, and an annular member securedto the carrier and formed with a channel to receive said separable member.

RALPH WILLIAMS.