contained within the load cell to 0 pounds this same electrical signal resets the revolution counter 31 to 0 revolutions when the shaft 12 has turned sufficient revolutions to cause the crosshead 19 to compress the ball 22 exactly one inch or other specified distance from the point of initial contact by the crosshead the preset counter 31 stops the drive motor 10 the same electrical signal which stops the motor also operates the solenoid valve 34 to activate the piston of air cylinder 36 and this immediately forces the two needles 25 and 26 through the wall of the hollow ball 22 as shown in fig3 when the upward travel of block 38 causes it to engage a limit switch on the rest plate 21 not shown a timer switch not shown is activated to open a solenoid valve in the cement line 44 pressurized cement of the type described flows through the passage 43 and needle 26 into the ball 22 to form a puddle around the two needle punctures approximately 1 2 1 cc of cement per ball is used when the cement has been injected the cement solenoid valve not shown is closed automatically by a delay timer arresting the flow of.