MANUFACTURE OF CEMENT PIPE 



THE Mccracken pipe machine 



The pipe machine at the Continental Ranch is known as the 

 McCracken machine, after the designer. It is made at Sioux City, 

 Iowa. A view of the machine and ecpiipment is given in Fig. 4. A 

 cut showing all features of the McCracken mechanism is shown in 

 Fig. 6. The main frame is bnilt of angle iron and is strongly braced. 

 The frame of the No. 2 machine at Continental is 7 feet 6 inches long 

 by 3 feet 8 inches wide by 10 feet high. The pulley shown at the 

 extreme right is the main pulley, driven by belt, at a speed of about 

 225 R.P.M. The heavy vertical shaft at the front of the machine is 

 called the packer shaft. It rotates at 330 R.P.M., meanwhile rising 

 and descending through the pulley at the top. The vertical motion 

 is given to the packer shaft by a powerful lever, hinged at the back 

 and operated by a slow-moving crank on the large gear wheel. The 

 outside form, or jacket, rests on a table, which is revolving for all 

 sizes up to 14 inches, and is stationary for larger sizes. The cement 

 mortar, after being transferred from a concrete mixer, is fed into 

 the hopper seen at the extreme left. The mortar is carried up by 

 the link bucket elevator and discharged through a chute into the 

 pipe mold. The size and number of buckets is determined by the 

 size of the pipe. The operation of the machine is controlled by a 

 clutch on the main pulley. 



On the lower end of the packer shaft is the packer-head, shown 

 separately in Fig. 5. It consists of a cylinder made of the hardest 

 grade of white iron surmounted by backward-curved vanes, either 

 two, four, or five, depending on the size of pipe being made. The 

 vanes (often called wings) catch the mortar as it falls into the form 

 and plaster it rigidly against the form. The rotating cylinder, 

 called the trow^el, follows, and increases the density, and, at the 

 same time, gives the interior of the tile or pipe a smooth uniform 

 glazed surface. The packer rod makes 50 revolutions during each 

 ascent. At least two sets of forms are used, so that while one is 

 being used at the machine, the other can be taken to the curing 

 shed, where it is "stripped" ofif from the tile and returned to the 

 machine. Two-wheeled carriers with long handles are used for 

 moving the tile, since even a 12-inch tile and mold are heavy, weigh- 

 ing about 150 pounds, and a 16-inch green tile and mold weigh about 

 240 pounds. 



The operation, then, is to set a form, or jacket, on the table, ro- 

 tate the table so that the jacket comes beneath the packer-head, and 



