MaXL'FACTI'RIv of CKMIvNT Pll^g 



87 



The ordinary forms, consisting of core, jacket, and tongue and 

 groove rings, such as are used for hand-tamped pipe, are used with 

 the Sanders machine. Thus, a contractor who has an equipment of 

 forms for hand-made pipe need not buy a new equipment. The 

 packer is a long revolving cylinder which is lowered into the space 

 between the core and jacket. On the bottom of the packing cylin- 

 der and held by rivets, there are three or more chilled iron flat- 

 bottomed "shoes" which are tilted at a small angle. When the 



Fig. 11. — The Sanders (Pomona) pipe machine. 



cylinder reaches the bottom, shovelers begin to throw mortar into 

 the forms. The mortar accumulating and passing beneath the re- 

 volving shoes raises the cylinder and the mortar is packed into the 

 form densely, the pressure being downward rather than outward as 

 in the McCracken system. When the cylinder reaches the top it is 

 held by a band brake while the table is rotated so as to bring another 

 (empty) jacket under the packer, and the cylinder is then lowered 

 again by partially releasing the brake. Meanwhile the top, or 

 tongue, joint is made on the cement pipe by workmen, and the core 

 is removed. The form containing the pipe is wheeled away to the 

 curing floor, where the jacket is stripped ofY. The packing cylinder 

 makes about 40 revolutions per pipe, the number depending upon 

 how fast the mortar is fed, and about 30 seconds of time is required 

 in this operation. 



The table on which the forms rest has three grates for forms, 

 so that while one pipe is being made, another is being removed and 



