Item Number:

R and L: Releasing Tap Holder
IS-5

INSTRUCTION SHEET FOR USE OF SOMMA R & L
RELEASING TAP HOLDERS • ADJUSTABLE RELEASING TAP HOLDERS • 
RELEASING DIE HOLDERS • NON-RELEASING TAP HOLDERS

Ready to start threading operation. Clutch slightly engaged (A) and (C).

When tap contacts work, spindle (C), clutch ring (A) becomes fully engaged for positive driving power.

When end of pullout is reached clutch ring (A) springs back instantly, leaving ample clearance between contact points of clutch ring and spindle, preventing re-engagement or hammering of clutch points.

OPERATION OF RELEASING TAP HOLDERS

Advance the Tap Holder until the Tap enters a short distance into the work, then stop forward motion of the tool and let the spindle of the Tap Holder pull out until it releases and revolves with the work.

When the direction of work rotation is reversed, the spindle will stop revolving and the Tap will unthread itself out. The Tap Holder will be ready for threading again as soon as it engages the next piece.

Continue advancing the point at which the forward motion of the turret is stopped, until this distance, plus the amount of pullout, produces the desired length of thread.

The shortest length of thread that can be tapped is equal to the pullout distance (as shown on the chart below) plus the slight amount necessary to engage the Tap.

On multiple spindle automatics, it is very important that the clutches of the machine for threading on and off are not slipping; otherwise the Tap will feed on or off too slowly and result in poor threads.

ADJUSTABLE RELEASING TAP HOLDERS

Mount the Tap Holder Shank in the turret of the machine, leaving the Pt. #18 Clamp Screws loose enough so that the Pt. #17 Body can be moved freely.

Insert tap into Pt. #2 Spindle using a good concentric tap bushing.

With Pt. #18 Clamp Screws loose as described above, start tap into work and stop spindle after it has entered two or three threads. Tighten Clamp Screws and proceed with tapping operation as explained above.

Pullout for Releasing
CAT NO. STD. CLUTCH NUT
TH000
TH00
TH1
TH2
TH3

TH4
 1/8
1/8
5/32
7/32
1/4

5/16
CAT. NO.  SHORT CLUTCH NUT
TH000-S
TH00-S
TH1-S
TH2-S
TH3-S
TH3-NBG
TH4-S
TH4-NBG		 .100
.100
.115
.156
.167
.167
.203
.203

 
Part No.
16. Shank
17. Head
18. Clamp Screw


(CUP) (NEW STYLE)
11 (FLAT)
(OLD STYLE) 
1. Pawl Pin
2. Spindle
3. Set Screw
4. Pawl
5. Pawl Spring
6. Clutch Spring
7. Clutch Washer
8. Clutch Nut
8-S Short Clutch Nut
9. Clutch Ring
10. Body
11. Cover Plate
11C Cup Style Cover Plate
12. Cover Plate Screw
13. Shank Spring
14. Spindle Nut

  

CHANGING CLUTCH NUTS OR DIRECTION OF TAPPINGS

To Change clutch nuts or direction of tapping, disassemble Tap Holder by first removing Part #14 spindle nut with hex wrench and then removing the Part #13 shank spring.

Next, pull the Part #2 spindle out of the front of the Part #10 body along with the Part #6 clutch spring and Part #7 clutch washer. Hold Part #4 Pawl with fingers so as not to have Part #5 Pawl Spring fly out.

Then remove Part #8 clutch nut from the body by unthreading it with a hex wrench.

To reassemble the Tap Holder, first replace the Part #9 clutch ring with the side stamped "R" showing for right hand threads, or the side stamped "L" showing for left hand threads. Next screw in the clutch nut making certain it is tightened securely. (Be sure lugs of clutch ring are in the holes in the body before tightening clutch nut.) Then drop the clutch spring (large end first) over the shank of the spindle, next drop the clutch washer (open side up) over the shank being sure it goes over the larger shank diameter.

Next rotate the Part #4 pawl in the spindle so that it is on the side stamped "R" for right hand threads or on the side stamped "L" for left hand threads, and placing the Part #5 pawl spring in the hole on the same side.

Stand the spindle, shank end up, and drop the body over it, holding in the pawl so that it fits into the body. Next insert the shank spring into the space between the body and the spindle and lock it in place with the spindle nut. Tap Holder is now ready for use

Note: It is extremely important that the side of the clutch ring that shows and the side of the spindle in which the pawl is placed are both the same, either "R" or "L", as is required. Also be certain that all parts are assembled exactly as shown in diagram and particularly that Part #7 clutch washer is assembled with open side facing back towards the shank as shown.

NON-RELEASING TAP HOLDERS

Non-Releasing Tap Holders are used on machines that do not require the releasing feature.

These tools have the pullout feature which allows the Tap to follow the lead of the thread thereby compensating for any error in the rate of feed of the machine.

It is important that the Tap Holder be fed so that it hangs back a little, that is the spindle should be pulled out partially so that it can move either direction in following the lead of the thread being cut.

NOTE: Extra versatility can be obtained from the Somma R&L Tap Holder by use of adapters for Acorn Dies and Button Dies as shown in photograph.