Numa Patriot RC50 Maintenance manual

MANUFACTURER OF DOWN HOLE HAMMERS AND BITS
©2020 Numa All Rights Reserved
P.O. Box 348 •646 Thompson Road •Thompson, CT 06277 USA
US Toll Free: (800) 356-NUMA •Tel: [phone] •Fax: [phone]
E-mail: [email protected]
Website: www.numahammers.com
Patents 4,530,408 4,919,221 4,962,822 5,205,363 5,984,021 5,992,537 6,021,856 7,422,074
PatriotRC50
CARE & MAINTENANCE
INSTRUCTIONS

Patriot®RC50
TABLE OF CONTENTS Page
Section I Description ..................................................................... 1
Functional Description ............................................................. 2
1. Connector Tube .............................................................. 2
2. Collection Tube ............................................................... 2
3. Backhead ........................................................................ 2
4. Pin ..................................................................................... 2
5. Backhead Bearing.......................................................... 2
6. Check Valve Seat........................................................... 2
7. Check Valve ................................................................... 2
8. Check Valve Spring ....................................................... 2
9. Feed Tube ........................................................................ 3
10. Piston ................................................................................ 3
11. Case ................................................................................. 3
12. Snap Ring......................................................................... 3
13. Bit Bearing........................................................................ 3
14. Bit Retaining Rings........................................................... 3
15. Chuck............................................................................... 3
16. Metering Sleeve .............................................................. 3
Section II Maintenance......................................................................... 4
Disassembly .............................................................................. 4
Hammer Disassembly .............................................................. 4
Inspection.................................................................................. 6
General Hammer Assembly.................................................... 9
Hammer Assembly ................................................................... 9
Section III Parts Identication ............................................................. 12
Patriot RC50 Exploded View .................................................. 12
Part Number Reference ......................................................... 12
Section IV Air Consumption Charts ................................................... 13
Section V Lubrication .......................................................................... 14
Section VI Storage............................................................................... 15
Short Term................................................................................ 15
Long Term ................................................................................ 15
Restarting................................................................................. 16
Section VII Button Bit Maintenance ................................................... 17
General.................................................................................... 17
Sharpening .............................................................................. 17
Section VIII Patriot RC50 Recommended Spares............................. 18

04/23/10
MANUFACTURER OF DOWN HOLE HAMMERS AND BITS
WARRANTIES AND REMEDIES
LIMITED WARRANTY
Numa warrants that the Product will be new and free from defects in material and workmanship
under normal use as contemplated by this Contract for a period of six (6) months from the date of
shipment.
Except for the foregoing warranty, Numa disclaims all warranties and representations wherever
made, including warranties of merchantability, durability, length of service, or tness for a particular
purpose.
Any alteration or modication of the original product without the express written consent of
Numa will void this warranty.
REMEDY
If, during such warranty period, Buyer promptly noties Numa in writing of any defect and
establishes that the above warranty is not met, Numa shall either repair or replace the Product or
credit the customer, as it deems necessary to meet the warranty.
Such repair, replacement, or credit of Product shall constitute complete fulllment of Numa's
obligation under this warranty, and upon the expiration of the original warranty period, all of Numa's
obligations hereunder shall terminate.
LIMITATION OF LIABILITY
Numa shall not be liable to Buyer whether in contract, in tort (including negligence and strict
liability), under any warranty or otherwise, for any special, indirect, incidental or consequential loss
or damage whatsoever, including (without limitation) loss arising from delay, cost or capital and loss
of prots or revenues. The remedies set forth in this Contract are exclusive, and the total cumulative
liability of Numa under this Contract or for any act or omission in connection therewith or related
thereto, whether in contract, in tort (including negligence and strict liability), under any warranty or
otherwise, is limited to the price paid by Buyer for the Product.
The WARNINGS, CAUTIONS and NOTES used throughout the text of this
instruction book are dened as follows:
WARNING A specic procedure or practice that must be strictly followed,
or a specic condition that must be met, to prevent possible
bodily harm.
CAUTION A specic procedure or practice that must be strictly followed,
or a specic condition that must be met, to prevent damage
to the equipment.
NOTE Important supplemental information.
Numa®,Champion, and Patriot
are registered trademarks of Numa.

11/06/20 Page 1
Patriot®RC50
SECTION I
DESCRIPTION
GENERAL DESCRIPTION
The Patriot RC50 is a valveless, pneumatically operated reverse circulation drill designed
to utilize Numa 5-1/4" to 5-3/4" (133 mm to 146 mm) diameter reverse circulation bits in a
wide range of rock sampling applications.
The Patriot RC50 hammer design incorporates a hardened reversible case and a large
diameter collection tube. Backheads having threads compatible with the major reverse
circulation drill rods are available for the Patriot RC50. The large bore design of the Patriot
RC50 provides uncontaminated rock sampling without sacricing the high performance levels
associated with Numa down hole hammers.
The Patriot RC50 was specically designed to provide maximum performance on the
drill rigs most commonly used in rock sampling applications. The Patriot RC50 hammer
is designed to operate using air pressure from 150 PSI to 500 PSI (10.2 Bar to 34.5 Bar) with
compressors ranging in size from 425 CFM to 1050 CFM (201 to 496 Litres/Second). When
drilling conditions require supplementary hole cleaning, additional hole cleaning air can be
passed through the feed tube by removing the o-rings from the end of the feed tube which
seals on the collection tube. Refer to page 13 for the air consumption charts and pages 5
and 9 to facilitate the removal and installation of the o-rings.
Patriot RC50
Weight w/o Bit: 156 lbs. (71 kg)
Outside Diameter: 4-7/8" (124 mm)
Hammer Length:
Shoulder to Shoulder 41-13/16" (106 cm)
Shoulder to Bit Face 46-15/16" (119 cm)
Backhead API Thread Available for Reverse Circulation
4-1/2 OD Drill Rod
Table 1-1 General Hammer Specications
5-1/4" (133 mm) 33 lbs. (14.9 kg) 5-5/8" (143 mm) 34 lbs. (15.4 kg)
5-3/8" (137 mm) 33 lbs. (15.0 kg) 5-3/4" (146 mm) 35 lbs. (15.8 kg)
5-1/2" (140 mm) 34 lbs. (15.2 kg)
Table 1-2 General Bit Specications
NOTE
NUMA 5-1/4" TO 5-3/4" (133 MM TO 146 MM) BITS ARE AVAILABLE IN A
REVOLUTIONARY CONCAVE FACE DESIGN TO TAKE ADVANTAGE OF THE PATRIOT
RC50 PERFORMANCE. OTHER SIZES MAY BE AVAILABLE UPON REQUEST.

Page 2 11/06/20
Patriot®RC50
FUNCTIONAL DESCRIPTION
1. CONNECTOR TUBE
The connector tube ts in the backhead and on top of the collection tube to connect
the drill to those reverse circulation drills rods that use connector tubes.
2. COLLECTION TUBE
The collection tube extends from the check valve seat to the bit and transfers the
collected formation sample to the inner drill pipe of the reverse circulation drill rod.
The collection tube is designed to be easily replaced.
3. BACKHEAD
The backhead connects the hammer to the drill rod. Standard backheads are
available with threads that are compatible with most 4-1/2 reverse circulation drill
rod. Wrench ats are provided for disassembling.
4. PIN
Two pins align the feed tube into the backhead. They are made of hardened steel to
ensure long life.
5. BACKHEAD BEARING
The backhead bearing alligns and seals the backhead into the case bore.
6. CHECK VALVE SEAT
The check valve seat provides the sealing surface for the check valve and is located
in the backhead. The check valve seat locates the collection tube in the proper area.
7. CHECK VALVE
The check valve maintains pressure in the hammer when the air supply has been shut
off. The pressure in the hammer balances the hydrostatic pressure in the hole thereby
preventing contaminants from entering the hammer.
8. CHECK VALVE SPRING
The check valve spring provides tension under the check valve to keep it closed. It
is compressed as the air is turned on.

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Patriot®RC50
9. FEED TUBE
The feed tube supplies the main air into the chambers located in the piston. It is
connected to the backhead by two pins. The feed tube is designed with a long
bearing surface to maintain alignment in the backhead.
10. PISTON
The piston functions as the only moving part in the hammer, controlling the operational
air cycle. The percussive action of the piston striking the bit transfers the energy
through the bit in order to fracture rock formations.
11. CASE
The case is designed to contain the internal parts which make up the hammer
assembly. The case is reversible and hardened to resist wear and to extend life in
abrasive conditions.
12. SNAP RING
A snap ring positions the internal parts in the hammer and prevents the piston from
falling out when the chuck, bit retaining rings and bit are removed.
13. BIT BEARING
The bit bearing guides the bit to insure proper alignment between the piston and the
bit. The bit bearing is a slip t with a bit bearing retainer o-ring in the chuck end of the
case. The bit bearing is located by a snap ring which is inserted into the main bore.
14. BIT RETAINING RINGS
The bit retaining rings are designed to allow the bit to move between the drilling and
cleaning positions and prevent the bit from coming completely out of the hammer.
The bit retaining rings consist of two matched halves and are held together with the
bit retaining ring o-ring.
15. CHUCK
The chuck threads into the bottom end of the case wit a large cross section thread
form. It has internal splines that mesh with the splines on the bit body to transmit
rotation. Wrench ats are provided for disassembling.
16. METERING SLEEVE (SOLD SEPARATELY)
The metering sleeve facilitates sample ow through the collection tube. It should
always be 1/8" (3 mm) smaller than bit diameter. The sleeve seats on a shoulder
located on the OD of the chuck.

Page 4 11/06/20
Patriot®RC50
SECTION II
MAINTENANCE
DISASSEMBLY
•If at all possible, the backhead and chuck / metering sleeve should be broken loose
on the drill rig; this is much easier than trying to do so after the drill has been removed
from the drill rig. The connector tube, if used, should be removed at this time. Cap
the backhead to reduce external contamination. Using a small screwdriver pick the
o-rings from the inside diameter of the small end of the connector tube.
CAUTION
USE CAUTION WHEN HANDLING DOWN THE HOLE HAMMER PARTS. NUMA HAMMER
PARTS ARE MANUFACTURED FROM HARDENED, HEAT TREATED MATERIALS. DROPPING
OR STRIKING THESE PARTS MAY CAUSE SEVERE DAMAGE. STRIKING THE HAMMER
PARTS WITH HAMMERS, CROWBARS OR LIKE INSTRUMENTS WILL VOID THE WARRANTY.
•Maintenance should be performed in a clean environment.
• Tools needed: overhead crane, hammer stand, chain vise, 2" (51 mm) diameter brass
rod, rubber mallet, snap ring pliers, press, a small screwdriver and a scribe.
•Clean the outside of the hammer. This will insure a good surface to clamp on.
•Using an overhead crane place the hammer horizontally on a hammer stand and
secure the hammer with a chain vise. Place the chain vise on the area of the case
where the bit bearing is housed when working on the chuck end of the hammer. When
working on the backhead end of the hammer, place the chain vise on the area of the
case where the backhead bearing is housed.
CAUTION
THE ACCEPTABLE CLAMPING AREAS START 4-1/2" (114 MM) FROM EITHER CASE END,
TO AN ADDITIONAL 2-1/2" (64 MM) BEYOND THIS POINT. PLACING THE CHAIN VISE
ON THE AREA OF THE CASE WHERE THE PISTON CYCLES OR ON THE THREADED AREAS
CAN DISTORT THE CASE AND THE CASE THREADS, RESTRICT PISTON MOVEMENT AND
VOID THE WARRANTY.
HAMMER DISASSEMBLY
•Break the bit and chuck loose from the case.
•Remove the bit, chuck and bit retaining rings from the case. Remove the metering
sleeve from the chuck.
•Using a small screwdriver, remove the o-ring from the chuck.

11/06/20 Page 5
Patriot®RC50
•Using a small screwdriver, remove the o-ring from the bit retaining rings.
•Break the backhead loose from the case.
•Remove the connector tube from the backhead. Use a small screwdriver to remove
the o-rings from the connector tube inside diamter.
•Using a rubber mallet, tap the bottom of the collection tube until it protrudes out the
backhead. Grab with both hands and remove.
•When the collection tube is removed, unscrew the backhead from the case.
CAUTION
REMOVING THE BACKHEAD ALSO REMOVES THE FEED TUBE, CHECK
VALVE SPRING, CHECK VALVE AND CHECK VALVE SEAT. TWO PINS
WITH A HOLE IN THE CENTER HOLD THESE PARTS IN THE BACKHEAD.
•To remove the feed tube, check valve spring, check valve and check valve seat
from the backhead, stand the backhead on the end so the feed tube is pointing up
and vertical. Place a scribe in the pin hole. While pushing the feed tube into the
backhead to relieve any force created by the check valve spring, wiggle the scribe
as you pull the pin from the backead. Repeat to remove other pin.
•Remove the check valve seat, check valve, check valve spring, and feed tube from
the backhead. Using a screwdriver, remove the backhead bearing from the groove
located on the outside diameter of the backhead. Remove the backhead o-ring from
the backhead.
•Using a small screwdriver, pick the feed tube o-ring from the outside diameter and
two collection tube o-ring rings from the inside diameter of the feed tube.
•Using a small screwdriver, pick the check valve seat o-ring from the outside diameter
and the collection tube o-ring form the inside diameter of the check valve seat.
•Using the 2" (51 mm) diameter brass rod from the chuck end of the case, push the
piston out of the backhead end of the case.
•Removal of the bit bearing and bottom end snap ring is not necessary for routine
maintenance. If necessary, use a small pick to remove the bit bearing retainer o-ring.
Using a long 2" (51 mm) diameter brass rod, go through the backhead end of the
case and tap the bit bearing out of the chuck end of the case. The bit bearing is a
slip t. To remove the snap ring, insert the piston into the backhead end of the case
with the serial numbers toward the snap ring. Using a 2" (51 mm) diameter brass rod,
tap on the piston until the snap ring comes out of the chuck end. Remove the piston
from the case.

Page 6 11/06/20
Patriot®RC50
INSPECTION
•All parts should be washed in a clean solvent before they are inspected and
reassembled.
WARNING
USE CLEANING FLUIDS THAT ARE NONFLAMMABLE AND AVOID
BREATHING THE FLUID VAPORS.
•Handle all parts carefully, hardened parts may chip if dropped on a hard surface.
COLLECTION TUBE
•Inspect the outside diameters for nicks, burrs and scoring.
•Remove all minor irregulatities with emery cloth.
•Check the length and I.D. size (at the chuck end) of the collection tube. The tube I.D.
should be no bigger than 1-5/8" (41 mm) and the length should be al least 37-1/2" (95
cm).
NOTE
- Due to the angle of the exhaust into the collection tube two
sides will show increased wear.
- To increase the life of the collection tube, it is important to
index the bit 90° away from the worn area of the collection
tube. This should be done after each hole.
- The wear on the collection tube is determined by a visual
inspection on the last two inches of the bit end of the
collection tube.
BACKHEAD
•Inspect the threads and pin hole for cracks and burrs.
• Remove all burrs on the thread with a ne le.
•Replace if necessary.
BACKHEAD BEARING
•Check for gouges or irregularities.
•Replace if necessary.