﻿CLAYS 
  OF 
  ^•EW 
  YORK 
  ^BH^B^^^^ 
  

  

  The 
  molding 
  macliine 
  consists 
  of 
  a 
  massive 
  frame 
  of 
  forged 
  steel 
  

   about 
  8 
  feet 
  high. 
  3 
  feet 
  up 
  from 
  the 
  gTound 
  is 
  the 
  delivery 
  

   table, 
  into 
  which 
  the 
  press 
  box 
  is 
  sunk. 
  Connected 
  with 
  the 
  hopper 
  

   above 
  the 
  machine 
  by 
  means 
  of 
  two 
  canvas 
  tubes 
  is 
  the 
  charger. 
  

   This 
  slides 
  back 
  and 
  forth 
  on 
  the 
  table. 
  It 
  is 
  filled 
  on 
  the 
  backward 
  

   stroke 
  and 
  on 
  its 
  forward 
  stroke 
  lets 
  the 
  clay 
  fall 
  into 
  the 
  mold 
  

   box. 
  The 
  chai'ger 
  then 
  recedes 
  to 
  be 
  refilled 
  and 
  at 
  the 
  same 
  time 
  a 
  

   plunger 
  comes 
  down 
  pressing 
  the 
  clay 
  into 
  the 
  mold. 
  As 
  the 
  upper 
  

   plunger 
  descends, 
  a 
  lower 
  plunger 
  which 
  forms 
  the 
  bottom 
  of 
  the 
  

   mold 
  moves 
  upward, 
  so 
  that 
  the 
  clay 
  receives 
  pressure 
  from 
  above 
  

   aid 
  below. 
  The 
  upper 
  plunger 
  then 
  rises, 
  and 
  the 
  lower 
  plunger 
  

   ascends 
  till 
  the 
  lower 
  surface 
  of 
  the 
  brick 
  is 
  even 
  with 
  the 
  table. 
  

   Again 
  the 
  charger 
  comes 
  forward, 
  shoving 
  the 
  green 
  brick 
  for- 
  

   ward 
  on 
  the 
  table, 
  the 
  lower 
  plunger 
  drops 
  and 
  the 
  mold 
  box 
  is 
  

   once 
  more 
  filled 
  with 
  clay. 
  The 
  faces 
  of 
  the 
  mold 
  are 
  of 
  hard 
  steel 
  

   heated 
  by 
  steam 
  to 
  prevent 
  adherence 
  of 
  the 
  clay. 
  Air 
  holes 
  are 
  

   also 
  made 
  in 
  the 
  dies, 
  but 
  are 
  apt 
  to 
  become 
  clogged 
  up. 
  The 
  pres- 
  

   sure 
  from 
  above 
  is 
  applied 
  by 
  a 
  toggle-joint 
  arrangement, 
  and 
  it 
  is 
  

   maintained 
  by 
  the 
  manufacturers 
  of 
  the 
  Boyd 
  dry 
  clay 
  presses 
  that 
  

   the 
  pressure 
  exerted 
  on 
  each 
  brick 
  is 
  150 
  tons. 
  One 
  to 
  six 
  bricks 
  

   can 
  be 
  molded 
  at 
  a 
  time, 
  according 
  to 
  capacity 
  of 
  machine. 
  On 
  a 
  

   four 
  brick 
  machine 
  about 
  20,000 
  are 
  molded 
  in 
  a 
  day. 
  

  

  The 
  hydraulic 
  dry 
  press 
  machine 
  is 
  in 
  use 
  at 
  Canandaigiia, 
  

   X. 
  Y. 
  In 
  this, 
  the 
  pressure 
  is 
  produced 
  by 
  a 
  pair 
  of 
  hydi'aulic 
  rams, 
  

   acting 
  from 
  both 
  above 
  and 
  below. 
  The 
  pressure 
  delivered 
  at 
  first 
  

   is 
  light, 
  being 
  only 
  240 
  pounds 
  the 
  square 
  inch 
  (Missouri 
  clays. 
  

   Mo. 
  geol, 
  sur. 
  11: 
  502), 
  and 
  this 
  is 
  followed 
  by 
  a 
  pressure 
  of 
  

   S700 
  pounds, 
  which 
  completes 
  the 
  pressing. 
  

  

  A 
  difficulty 
  encountered 
  in 
  the 
  dry 
  press 
  and 
  semi-dry 
  press 
  

   methods 
  is 
  the 
  imprisonment 
  of 
  air 
  in 
  the 
  brick 
  under 
  pressure, 
  

   with 
  the 
  result 
  that 
  the 
  compressed 
  air 
  tends 
  to 
  split 
  the 
  brick 
  when 
  

   the 
  pressure 
  is 
  released. 
  This 
  can 
  be 
  ob"\"iated 
  partly 
  by 
  allowing 
  

   the 
  plunger 
  to 
  descend 
  very 
  slowly, 
  gi^dng 
  the 
  air 
  time 
  to 
  escape, 
  

   and 
  also 
  by 
  leaving 
  small 
  vent 
  holes 
  in 
  the 
  top 
  and 
  bottom 
  of 
  the 
  

   mold. 
  

  

  