Welch Allyn 49540 User manual

Welch Allyn Multi Fiber
Illumination Headlight
System
Service Manual
Models: 49540,49520,49522,49524, 49526
Copyright 1997
Welch Allyn Inc.
4341 State Street Road
Skaneateles Falls, NY 13153-0220
Part Number 495623 Rev A.

Service Manual Welch Allyn Fiber Optic Headlight System
Introduction Page 2
Revision (History) Page
Rev. Description of Change ECN # Date Initial
A New Release 5-34457 1/14/97 JSJ/MD

Service Manual Welch Allyn Fiber Optic Headlight System
Introduction Page 3
To Service Personnel:
The information in this manual is subject to change without notice and should
not be construed as a commitment by Welch Allyn, Inc.
Welch Allyn assumes no responsibility for any errors that may appear in this
manual. If the product and/or its operation varies significantly from any
description herein, please contact the Welch Allyn Product Service Department
at 4341 State Street Road, Skaneateles Falls, New York 13153-0220, 1 800 669-
9771, [phone]
This product has been designed to provide a high degree of safety and
reliability. However, we can not guarantee against the deterioration of
components due to aging and normal wear.
All service and repairs must be performed by authorized Welch Allyn personnel
or agents, using Welch Allyn replacement parts. Failure to do so will invalidate
the product warranty.
Authorized service centers should refer to repair specification for proper test
and device history record requirements.
Please refer to the product warranty for specific coverage.
Welch Allyn, Inc.
Medical Products
4341 State Street Road
Skaneateles Falls, New York 13153-0220
USA
1 800 669-9771
[phone]

Service Manual Welch Allyn Fiber Optic Headlight System
Introduction Page 4
Service Manual
Welch Allyn Fiber Optic Headlight System
Table of Contents
Part Number Model name Section Page
49540 Luminaire
Disassembly / Repair 1 6-11
49540 Suspension Repair/Adjustment 1 11
495591-502 Headband Assembly 2 12
49543 Fiber optic cable 2 12
all Required tools 3 13
all Problem Solving 4 14
all Recommended spare parts Appendix A 15-16
all Drawings and Figures Appendix A
If you have technical questions, or need other assistance, call Welch Allyn
customer service personnel at 1-800-669-9771.
Cleaning Warnings:
DO NOT IMMERSE the Luminaire in any type of liquid. Do
not spray it heavily with any type of liquid. The liquid might enter the Luminaire
and create a service problem. DO NOT AUTOCLAVE the whole Luminaire. Only
the Joystick is autoclavable separately.
Follow Cleaning and Maintenance instructions in Owner's Manual PN495608.
Caution: Turn off light source before disconnecting fiber optic bundle from headlight or
light source. Clean exterior surfaces of Luminaire, headband, and fiber optic bundle by
wiping clean with any of these solutions: Banicide, Cidex, Cidex Plus, Cidex 7,
Metracide, 10% Wescodyne, 10% chlorine bleach, 70% Isopropyl alcohol, Wavecide-
01, mild soap and water solution.

Service Manual Welch Allyn Fiber Optic Headlight System
Introduction Page 5
Table of Reference Drawings (Appendix A)
Drawing # Description
495540 Welch Allyn Headlight Main Assembly . . .
495570
495550
Suspension / Luminaire Assembly ......
LuminaireAssembly .................
Note that drawings within this manual are for reference only. Consult factory for
current revisions.

Section 1 Disassembly & Reassembly
Service Manual Welch Allyn Fiber Optic Headlight System Page 6
Abstract of disassembly and reassembly of 49540 Luminaire:
The whole luminaire can be disassembled with the exception of the Mirror and
back plate which are pinned and glued to the bottom housing. If moisture is
present in the luminaire, replace the iris assembly and clean the lenses by
following instructions in this manual. With the exception of the mirror, all
components can be replaced as necessary.
The following is the process for completely disassembling and reassembling the
luminaire for 'O' ring replacement. "O" rings are used not to seal out moisture
but to provide a smooth moveable connection between parts. Only replace 'O'
rings if they are worn, cracked, stretched out or missing. If the iris control sleeve
is too loose, then the O rings have failed.
1.1 Removing O rings:
__Unscrew joystick from the lower housing.
__Unscrew the bezel from the luminaire. Use the appropriate collet
or equivalent. The bezel is glued on.
__Unscrew the top nut. Use collet or equivalent.
__Pull the top cap off of lens housing.
__Remove O rings.
1.2 Remove Bottom Housing:
__Unscrew bottom housing from lens housing. These parts are
held together using a thread locking adhesive. Use of a collet
will be needed to break the bind of the thread locker.
Note: the back plate and the mirror can not be replaced as they are pinned and
glued into the bottom housing. If the mirror is broken or loose, replace the
complete bottom housing assembly.
1.3 Remove Iris Assembly:
__Unscrew the small pin in the side of the control sleeve.
Use 1/16" flat blade screwdriver.
Note: If the iris pin is sheared, it might be removed by grabbing it
with a small diagonal cutters and unscrewing it. If not, replace lens
housing Asy.
__Pull control sleeve from the lens housing.
__Remove 'O' rings.
__Unscrew the iris retaining nut using the Welch Allyn tool
T-14452 or equivalent.

Section 1 Disassembly & Reassembly
Service Manual Welch Allyn Fiber Optic Headlight System Page 7
__Heat the 2-56 setscrew holding the iris in place before
attempting to loosen it. The setscrew can be heated by
inserting the hex key into the setscrew and applying heat from a
soldering iron to the hex key wrench.
__Unscrew the 2-56 setscrew holding the iris in place. Use a
.035" hex key.
__Remove the iris.
1.4 Remove Condensing
Lenses and spacers
__Heat the three 2-56 setscrews before loosening due to the
threadlocker that is used. The setscrew can be heated by
inserting the hex key into the setscrew and applying heat from a
soldering iron to the hex key wrench. If the set screws become
stripped, then the entire lens and iris assembly will need to be
replaced.
__Unscrew the three 2-56 setscrews from the lens housing. Use a
.035" hex key.
__Remove: the spacer, condensing lens, spacer, and small
condensing lens.

Section 1 Disassembly & Reassembly
Service Manual Welch Allyn Fiber Optic Headlight System Page 8
Re-assembly of model 49540 Luminaire
Special notes for reassembly of Luminaire:
Refer to assembly drawing 495550 in this manual.
Use new set screws and 'O' rings when reassembling luminaire.
Remove any threadlocking adhesive from parts by chasing threads with taps or
dies.
Do not touch lenses or mirror with fingers. Clean them with cotton swabs and
lens cleaner.
1.5 Install Condensing
Lenses and spacers
__Insert clean condensing lens into the lens housing so that the
convex portion is up.
__Insert a condensing lens spacer into the Lens housing so the
large diameter is facing up. Push it down onto the condensing
lens.
__Insert the next lens (This lens is the same on both sides) into
the lens housing on top of the condensing lens spacer.
1.6 Install Iris assembly
__Insert the Iris Spacer into the Lens housing chamfered end first.
Push it down so it seats on the lens fully.
__Compress the spacers and lenses together using T14601 or
equivalent. At the same time, dip a set screw into the Loctite 425
threadlocker and Install it into one of the three holes in the Lens
housing using a .035" Hex wrench.
__Install the Iris into the lens housing, with the retaining clip of the
Iris assembly facing upwards. There is a slot in the side of the Iris
which has a tapped hole located in it. Align this tapped hole with
the slot in the Lens housing.
__Screw T14600 through the slot in the lens housing and into the
Iris; finger tighten. Note: This is temporary and will be removed
after the Iris is locked into place with the Iris retainer.
__Insert T14448 into the Lens housing so that the pin in the center
of the tool is in the Iris opening and the rubber part of the tool rests
on the Iris. Apply light downward pressure to T14448 and at the
same time, rotate the tool clockwise. Rotating the tool will cause
the Iris pin tool 14600 to rotate until it contacts the end of the slot in
the lens housing. Continue rotating the tool until the Iris opening
closes down onto the pin of T14448.
__Rotate the Iris counter clockwise using T14600 until the tool
contacts the opposite side of the slot. Hold 14448 steady while
performing this operation.

Section 1 Disassembly & Reassembly
Service Manual Welch Allyn Fiber Optic Headlight System Page 9
__Install a set screw with threadlocker Loctite 425 into the top
threaded hole on the Lens housing using a .035" hex wrench; while
at the same time, apply firm pressure downward with T14448.
Note: Over tightening of this set screw will cause the Iris to bind.
__Remove tool T14448.Apply 2 to 3 drops of Loctite 425
threadlocker to the Iris retainer threads, then Install the Iris retainer
using T14452.
Note: When the Iris is at full closed position, a .090" diameter pin should not go through
the hole in the center of the Iris. Open and close the Iris; the operation should be
smooth.
1.7 Assemble Bottom Housing to Lens Housing
__Open the Iris to full open position and blow out any dust in the
lens housing assembly using an Aero duster or equivalent.
__Close Iris.
__Blow any dust out of the bottom housing assembly with an aero
duster.
__Apply 3 to 4 drops of Loctite 425 threadlocker to the large
external threads of the lens housing, and screw it into the bottom
housing. Tighten the assemblies together with the appropriate
collet.
__Place the fiber optic cable leading from the Solarc Light Source
into the top of the luminaire assembly.
__Inspect the spot for any dirt or dark spots by shinning onto a
white piece of paper. Also Rotate the Iris and check for proper
operation. Any small dust spots not noticed within 2 seconds are
generally acceptable. Large, dark or hair-like spots are not
acceptable.
1.8 Control Sleeve and Top Cap
__Install (2) large O-rings into the lower grooves on the Lens
Housing.
__Install (1) large O-ring onto the top of the first shoulder of the
Lens Housing.
__Apply a light coat of Grease to all (3) O-rings.
__Assemble the Control Sleeve over the Lens Housing and down
to the O-rings. Rotate the Control Sleeve so that the hole in the
side of it is positioned above the threaded hole in the Iris; seen
through the slot in the Lens Housing.
__Push Control Sleeve down over the O-rings until seated; being

Section 1 Disassembly & Reassembly
Service Manual Welch Allyn Fiber Optic Headlight System Page 10
careful not to rotate the parts.
__Apply (1) drop of Loctite Adhesive to the threads of an Iris Pin
and install through the hole in the Control Sleeve and into the Iris.
Tighten w/ a screw driver until flush or just below.
__Rotate Control Sleeve back and forth to spread grease and
check for freedom of movement.
__Install (1) large O-ring onto the Lens housing and push down until
seated on top of the Control Sleeve.
__Install (2) large O-rings into the lower exposed grooves on the Lens
Housing.
__Install (1) small O-ring onto the Lens Housing so that it sit on the
shoulder just above the last Large O-ring.
__Apply a generous coat of Grease to the 2 lower O-rings.
__Apply a coat of Grease to the inside of the Top Cap.
__Install a Top Cap onto the Lens Housing so it rests on the O-rings.
Rotate the Top Cap while pushing it down over the O-rings. Continue
until seated.
__Install (1) Small O-ring down on top of the Top Cap.
__Apply 2-3 drops of Loctite 425 Threadlocker to the Lens Housing
threads.
__Install the Top Cap Nut onto the Lens Housing and tighten with the
appropriate collet or equivalent.
__Rotate the Top Cap a few turns to make sure it rotates smoothly.