GENERAL DESCRIPTION AND OPERATION
M 106
60
The Models8268-A( ) Dual Spindle Drills ore designed to automati-
cally feed to a preset depth, trip and return.
Thefollowing is a brief description of the various sections and their
function.
GEARING:Thegearing for these modelsis available in single or dou-
ble reduction planetary gearing assembliesto provide five (5) final
spindle speeds.
AIRMOTOR:Thevanetypeair motordevelopsa minimum of .7horse-
power.The motor will start within the first 1/4 inch of strokeand re-
main running thru the forward and retract stroke, automatically
shutting off upon completion of the cycle.
AIRPISTON:Theair piston is of the double acting type, providing the
forward and retract strokemovement.Thepiston has an area of 2.8
squareinchesand developsapproximately250 poundsofthrustwith
90 p.s.i.g.at the piston inlet.
VALVESECTION- Thevalve section housesthe SPOOLVALVE,BUT-
TONBLEEDVALVESandthe FEEDCONTROLVALVES.TheSPOOLVALVE
is a 4-way bleed type valve used to port air to the piston for the for-
ward and
retract
stroke.
Positioing
ofthespoolvalveis accomplished
by actuating the “F” or “R” Button BleedValves,located at the rear
of the head.
The BUTTONBLEEDVALVESexhaust air from the ends of the spool
valve,causingittoshifttotheforwardandretractpositions.Depressing
the Button BleedValve marked “F” shifts the spool valve to the for-
ward feedposition.Whenthedrill reachesthe preset depth,theStroke
Adjustment Screw will depressthe ButtonBleedValve marked “R”,
this shiftsthe spoolvalveto the retractpositionand retractsthe piston
completing the cycle.
Theneedletype FEEDCONTROLVALVESregulatethe flow of air from
the piston thus regulating the forward and retract roteof feed of the
piston.TheFeedControlValvemarked“F” regulatesthe forward feed
rate of the piston and the FeedControlValve marked “R” regulates
the retract feed rate of the piston.
TOOLRETRACTEDSIGNALPORT- this port is located in rear end of
PistonRod.Theportis pressurizedwhen the motorstartsand remains
pressurized during the drilling cycle until the motor shuts off when
the unit is fully retracted.
MANUAL OPERATION
Themodels8268-A() areshipped fromthe factory with the MANUAL
BLEEDVALVE(24130) installed in the “F” portatthe rearofthe Valve
Housing. If the unit is to be operated manually; loosen the two (2)
Screws(Y211-102)securing Cover(40582-) tothe ValveHousingand
removethe cover.Removethe ButtonBleedValve from the “F” port
atthe rearofthe ValveHousingand removethe PipePlug(Y227-2-L)
from the ”F” port at the top of the Valve Housing. Install the Button
BleedValve (24130) in the “F” port at the top of the Valve Housing
and seal off the “F” port at the rear of the Valve Housing using the
PipePlug(Y227-2-L).Replacethe Cover(40582-) and tighten Screws
(Y211-102)securing Coverto Valve Housing
Each time the BUTTONBLEEDVALVEmarked “F”
IS
depressedthe
unit will start in the advancing (forword) mode.Theunit will continue
to advance until the BUTTONBLEEDVALVEmarked “R” has been
depressed sufficiently to retract the unit. See SET-UPPROCEDURE,
PAGE4.Should on EMERGENCYRETRACTbedesired,install an addi-
tional Button Bleed Valve in the “R” port at the top Valve Housing.
TheEmergencyButtonBleedValvecon beusedto immediatelyretract
the unit in the event of a misaligned port or similar situation.
REMOTE CONTROL OPERATION
The Models 8268-A( ) con be used OSo single unit application or
in a multiple unit application. REMOTESTARTis accomplished by use
of a PressureBleedValve (port No.9600) installed in either the “F”
port at the rear of the ValveHousing or the “F” port in the top of the
Valve Housing.This pressurebleed valve is then connected, by me-
ansof 1/8” I.D.tubing, to a remoteoperatedvalve which, when actu-
ated, feeds air pressure to the PressureBleed Valve (9600). The
PressureBleedValvethen opens, bleeding air from “F’ part of Valve
Housing, causing Spool Valve to shift to the Forward Feedposition
thus starting the advancing (forward) mode of the unit.
REMOTERETRACTis accomplished by useof o PressureBleedValve
(port no.9600) installed inthe “R” portlocatedatthetop ofthe Valve
Housing. This pressure bleed valve is then connected to o remote
MANUALLYoperatedvalve in the some manner as the RemoteStart
circuit. This valve is used as an emergency Retractin the event of
a part misalignmentorsimilar situationonlyasthe unit,when properly
set-up and applied, will automatically retract and return to the start
position after reaching o pre-setdepth or stroke.SeeSet-UpProce-
dure page 4 and illustration on page 8.
SPECIALNOTE:Theair inlet and remoteportsof this tool hovetapered pipe threads and should not requirethread sealants,such as sealant
tapes or pipe joint compound. Thread sealants used improperly can cause valve or tool malfunction.
FORM 1824-2 PAGE 3 OF 20
