Welch Allyn 49540 Multi Fiber Illumination Headlight System

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 4619 Jordan Road, Skaneateles Falls, New York 13153-0187, 1 866-801-8428, 315-685-2993 This product has been designed to provide a high degree of safety and reliability. However, we cannot 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 specifications for proper test and device history record requirements. Please refer to the product warranty for specific coverage.
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, Wavecide01, mild soap and water solution.

Table of Reference Drawings (Appendix A)

Drawing # Description

• 495540 : Welch Allyn Headlight Main Assembly . . .
• 495570 : Suspension / Luminaire Assembly ……
• 495550 : Luminaire Assembly ……………..

Note that drawings within this manual are for reference only. Consult factory for current revisions. 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.

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.

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 threadlike.
  Note: The back plate and the mirror cannot 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.

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.

• Heat the 2-56 set screw 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 set screw holding the iris in place. Use a .035″ hex key.

• Remove the iris.

Remove Condensing Lenses and Spacers

• Heat the three 2-56 set screws before loosening due to the thread locker that is used. The set screw 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 set screws from the lens housing. Use a .035″ hex key.
• Remove: the spacer, condensing lens, spacer, and small condensing lens.

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 thread locking 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.

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.

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 T14448 steady while performing this operation.
• Install a set screw with thread locker 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 thread locker 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.

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 threadlike 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.

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 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 Thread locker 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.

Abstract of disassembly and reassembly of 49540 luminaire suspension: The following is the process for adjusting or repairing the luminaire suspension. In most cases the end user will probably indicate that the luminaire no longer stays where it is put. This condition is caused by wear to the friction washers in the suspension mechanism or loosening of the assembly screws. The assembly screw(s) can be tightened to compensate for the wear of the washers or in severe cases, the washers will need to be replaced.
Special notes for Repairing the Luminaire Suspension:

•  Refer to assembly drawing 495570 in this manual for proper reassembly and torque specifications.
•  Reapply thread locking adhesive (Loctite 425) to any screws that are tightened or loosened.
  • Remove the set screws located inside the three pivot nuts, using a 1/16″ hex key.
  • Loosen the three pivot nuts to break any of the thread locker free so that the nut turns freely, and blow out any loose debris left from the old thread locker.
  • Tighten the three pivot nuts to the specified torque as described on drawing 495570.
  • Apply a drop of Loctite 425 thread locker onto the threads of a set screw and install it into one of the pivot nuts. Tighten with a 1/16″ hex wrench. Repeat for the remaining two screws.

Abstract of adjustment / repair of the Headband:
The following is the process for adjusting or repairing the headband. There are only two replaceable components of the headband assembly, the three vinyl pads (1set) and the fiber-optic clips. The fit adjustment controls can be adjusted if the knobs are too hard to turn or if the headband will not maintain its fit (Loosens).

• Refer to assembly drawing 495540 in this manual for further details.
• If the vinyl pads need to be removed and reused, be sure to release snaps by pushing a fingernail or equivalent between the two halves of the snap. The vinyl is extremely thin and will tear if pulled on directly.

Comfort/Fit Adjustment Knob:

• Tighten the screw in the center of the adjustment knob if the headband continues to loosen.
• Loosen the screw in the center of the adjustment knob if the knob is too hard to turn.

Fiber Optic Clips:

• Remove the vinyl pad on the top support of the headband assembly. See note above.
• Unscrew the two screws that hold the respective clip in place and Remove the clip.
• Reassemble in reverse order.

Special Notes for the Fiber Optic Bundle:

The Fiber optic bundle (49543) is a multi-fiber cable which transmits the light generated at the light source into the luminaire assembly. There is no repair for this item. It must be replaced if the fibers become damaged.
Note: Refer to owner’s manual (495608) for cleaning and disinfection.
Broken Fibers:

• Hold one end of the fiber bundle up to a light and look at the other end. Dark areas are broken fibers. The fiber optic cable will need to be replaced if the dark area covers 20% or more of the entire bundle surface.

Tools and Equipment List:

• 1/16″ hex key
• General purpose tools / supplies:
• .035″ hex key
• Peer #7 tweezers

• 4 Flat Blade screwdriver

• 2 Phillips screwdriver

• 1 Phillips screwdriver

• Collet Block
• 5C Collet for Top Nut Cap (.382″)
• 5C Collet for Lens Housing (.438”)
• 5C Collet for Bezel (1.06″)
• Jeweler’s’s flat-blade screwdriver (1.5mm x 40mm) for Iris Pin.
• Aero Duster (“canned air”) or equivalent. Compressed air is not recommended due to oils and
• moisture that are often found in compressed air.
• T14600: Extended iris pin.

Welch Allyn tools and fixtures:

• T14448: Iris aperture adjustment tool.
• T14452: Spanner wrench for iris retainer nut.
• 49501 Solarc Light Source
• 49543 MFI Fiber Optic Cable

Troubleshooting

Symptom| Possible Cause|

Procedure

---|---|---
Low Light

Output Light Spot not defined.

| Damage has occurred to the fiber optic cable.

The attenuator on the light source is turned counter clockwise.

The light source is defective.

The luminaire may be flooded.

| Replace the fiber optic cable.

Adjust the attenuator to full bright position.

Repair the light source per service manual 495621.

Disassemble the luminaire and repair as necessary.

Spot size control is hard to turn.| The O-rings are binding.| Replace and lubricate all O-rings.
Luminaire droops.| Friction washers in suspension are worn out.| Readjust suspension or replace washers if necessary.
Headband won’t keep desired fit.| The fit adjustment is slipping.| Tighten the adjustment screw on the appropriate adjustment knob

Bubble #

| Part Number| Description| Quantity Luminaire|

Drawing Number

---|---|---|---|---
| 495562| BUNDLE CLIPS| 4|
| 495594| WASHER, COUNTERSUNK| 2|
| 495608| MANUAL| 1|
| 49571| JOYSTICK ASSY| 1|
0002| 495591-502| HEADBAND ASSY TAMPO| 1| 495540
0004| 106102-25| FHPS 6-32 X.312| 2| 495540
0006| 495565-1| LABEL| 1| 495540
0007| 495596-502| PAD SET| 1| 495540
0001| 495573-4| MOUNT,HEADBAND-ANODIZED| 1| 495570
0002| 495572-3| LINKAGE, LONG-ANODIZED| 2| 495570
0003| 106142-8| WASHER, BELVILLE (.375 OD)| 6| 495570
0004| 106103-32| WASHER, FLAT FRICTION| 6| 495570
0005| 495571-3| LINKAGE, SHORT-ANODIZED| 2| 495570
0006| 495577| SPACER, HEADBAND MOUNT| 1| 495570
0007| 495575| NUT, PIVOT| 3| 495570
0008| 495574| SCREW, PIVOT| 3| 495570
0009| 106113-17| SET SCREW (#6-32 X .125)| 3| 495570
0001| 495507-3| TOP CAP NUT ANODIZED| 1| 495550
0002| 495506-2| TOP CAP ANODIZED| 1| 495550
0003| 495505-3| CONTROL SLEEVE ANODIZED| 1| 495550
0004| 106104-33| O-RING| 2| 495550
0005| 106104-32| O-RING| 6| 495550
0006| 495513| SPRING CLIP, FERRULE| 1| 495550
0007| 495504-1| LENS HOUSING| 1| 495550
0008| 495901| CONDENSER LENS #1| 1| 495550
0009| 495509| SPACER-CONDENSER LENS| 1| 495550
0010| 495902| CONDENSER LENS #2| 1| 495550
0011| 495510| SPACER-IRIS| 1| 495550
0012| 710114| 2-56 X 1/16 LG SET SCREW| 4| 495550
0013| 495515| IRIS DIAPHRAGM| 1| 495550
0014| 495517-1| PIN,IRIS| 1| 495550

Bubble #

| Part Number| Description| Quantity Luminaire|

Drawing Number

---|---|---|---|---
0015| 495516-1| RETAINER, IRIS| 1| 495550
0016| 495501-9| BOTTOM HSG-ANODIZED| 1| 495550
0017| 495512| JOYSTICK INSERT| 1| 495550
0018| 495903| OBJECTIVE LENS #3| 1| 495550
0019| 495502-3| BEZEL-OBJ LENS ANODIZED| 1| 495550
0020| 495904-1| MIRROR| 1| 495550
0021| 495503-6| MIRROR PLATE ANODIZED| 1| 495550
0022| 106126-22| SPIRAL PIN, (.033 DIA X .125)| 2| 495550
0023| M30397| LOCTITE 330| 0| 495550
0024| M30398| LOCTITE 738 ACTIVATOR| 0| 495550
0026| M30328| LOCTITE 262-31| 0| 495550
0027| M30373| LOCTITE 425 ASSURE THDLCKER| 0| 495550
0028| M40156| DOW CORNING 3452 LUBE| 0| 495550

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