Screw Tapping Machines or Attachments.
Year: 1890

page_text: Date of Application, 16th Dec., 1890
Complete Specification Left, 16th Oct., 1891-Accepted, 5th Dec., 1891
PROVISIONAL SPECIFICATION.
Screw Tapping Machines or Attachments.
I JOHN WILLIAM HARTLEY of California Engineering Works Stoke on Trent
in the County of Stafford Engineer do hereby declare the nature of this invention
to be as follows:-
Into the drill socket of a vertical drilling machine I fix a vertical spindle
which I call the main spindle, upon this spindle I attach an epycylic train of
wheels as follows. The upper bevel wheel I fix securely upon the main spindle
and upon the plane upper surface of this wheel 1 fix a stud which forms the
fulcrum of a stop lever which operates preferably in the same plane as the bevel
wheel. The outer end of this projects outwards nearly radially from axis to
main spindle the outer end being level with or beyond the periphery of bevel
wheel the inner end passes against a spiral main spring which prevents its move-
ment in one direction unless when the main spring is compressed, another lighter
spring serves to retain the stop lever in position against the main spring. When
stop lever is moved so as to compress the main spring I bring into action a detent
which operates against an inclined surface at inner end of stop lever and thus
retains it in position, at the same time holding the main spring in compression.
The train arms, of which I may have any suitable number, I insert into a bush
revolving upon main spindle. The outer ends of arms I carry in a suitable friction
ring which helps to retain them in position. The bevel wheels upon the train
arms run loosely, the arms as stated preferably being fixed. Upon one or more of
these bevels I fix a catch which engages against the outer end of the stop lever
already described and when the contact takes place the train arms are fixed in
position and cannot revolve upon their axes, but are carried round holding the
same position relatively with the first bevel wheel and also with the lower bevel
wheel. The lower bevel runs loosely on main spindle and has attached thereto
a sleeve through which the main spindle revolves. Fitting on the outside of this
sleeve I have a sliding bush, with arms attached on each side which- pass down-
wards in the direction of axis of main spindle. This bush slides and is free to
move or pass axially along the sleeve but by means of feather keys revolves with
it. The arms referred to project beyond and below the end of main spindle and
are attached at their lower end to a socket for carrying the tap. Upon the sleeve
above the sliding bush I arrange a spiral spring this spring when in operation
presses against the bush and forces the tap downwards into the hole. Upon the
sleeve on the underside of the bush I arrange a lighter spring which is merely intended
to bear the weight of bush and tap the lower end of this spring rests against a
collar at the lower end of the main spindle. The operation is as follows:-
The tap being fixed in the socket and entered into the hole to be tapped I start
the drilling machine the catch engages the end of stop lever and thus all the wheels
are fixed in one position and revolve with the main spindle. The tap is forced
into the hole by means of the spiral on the sleeve acting against the upper end of
the sliding bush, or by the drill feed motion. As soon as the tap reaches the
bottom of the hole the resistance causes the catch on the train arm wheel to press
heavily against the end of stop lever this pressure immediately overcomes the
resistance of the stop lever, pushes it aside, and compresses the main spring until
the detent comes into operation. The train arms are now free to revolve, and this
they do in the same direction as the drill spindle but at a reduced rate of
speed, as the lower-bevel which carries the tap is now stationary. The operator
Dow grips the the friction ring carrying the train arms and checks its motion when
immediately a reverse motion is given to the lower bevel and the tap is withdrawn.

page_text: The detent is now released and the operations may be again repeated. For large
taps I employ a long lever with frictional pressure against the train arm friction
ring.
Ithus accomplish the complete operation of inserting and withdrawing the tap
without as at present needing any reversing gear upon the drilling machine.
I have described this as being attached to a vertical drill for the convenience of
description only, but I may use it horizontally or otherwise by means of the
vertical play given to the sliding bush.
I do not need to follow the tap closely with the feed of the drill. Sometimes I
dispense with springs on sleeve and use a lever for entering tap. For different
sizes of taps I change the stop lever compression spring or I may by suitable
screws put on extra compression on the spring or in another method I move the
spring nearer to or further from the fulcrum. I use this machine or apparatus with
drilling machines that are provided with reversing gear by arranging a movable
stop on the lower bevel, when I engage the catch against this the machine may be
reversed and the tap withdrawn by the machine but without adjustable power.
If this is needed the spring arrangement may be duplicated under the lower wheel
and the catch disengaged by sliding it inwards or outwards on the train arm wheel.
In another method I attach the stop lever and detent arrangement upon a disc
corresponding with the upper bevel wheel. A similar disc below having a sleeve and
bush carrying the tap as described, works against the upper disc and the catch is
fixed to the lower disc and operates in a similar manner to the catch on the train
arm wheel. The reversing is now accomplished by a ratchet catch working between
the two discs. This arrangement provides adjustable force only as the tap is
inserted, the return action being positive with the drill spindle.
Dated this 15th day of December 1890.
J. W. HARTLEY.
COMPLETE SPECIFICATION.
Screw Tapping Machines or Attachments.
1 JOHN WILLIAM HARTLEY of California Engineering Works Stoke on Trent
in the County of Stafford Engineer do hereby declare the nature of this inven-
tion, and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
Figures 1, 2, 3, 4, 5, 6, & 7, in the accompanying drawing illustrate my improved
apparatus and this I construct as follows:-
Into the drill socket of an ordinary drilling machine I fix a vertical spindle A,
upon this spindle I attach an epicyclic train of wheels as follows. The upper bevel
wheel B I key securely on spindle A and fix upon the upper surface of B a stud C
which forms the fulcrum of a stop lever D. The lever D in this instance operates
in the same plane as the bevel wheel B. I construct this lever D in the form shewn,
and provide at the outer end a projecting face D³ of hardened steel of the form
shewn. The inner end D³ of lever D rests against the main spiral spring E and
thus its movement in the direction of the arrow F is prevented unless when com-
pressing spring E. The spiral spring G acting in tension holds the lever D against
the spiral E thus retaining the spiral E in its position. When end of stop lever D'
is moved in direction of arrow F spiral E is compressed and when the stop K
(which is a raised projection from the lever D) passes the inclined face H of the
detent H the spiral spring G draws the detent H forcibly against the stop K not
only holding the spring E in compression but by means of a slight incline on the
face of the detent H³ the spring E is still further compressed and the outer edge of
stop lever D is withdrawn still further clear of the stop Q. The position of the
foregoing with detent in operation is shewn in Figure 7. The train arms L of
which I may have any suitable number I insert into a bush M which revolves loosely
on spindle A. I carry the outer end of arms L in a friction ring N which connects

page_text: them together and maintains them in their relative positions. The bevel wheels
upon the train arms run loosely by preference, the train arms being fixed. Upon
one or more of these bevels I fix a catch P which engages against the outer end of
lever D. Figure 5 shews the catch P fixed on to one bevel only and practically
takes the place of catch Q. Figures 1, 2, 3, 4, 6, & 7, shew the catch Q attached to
the whole four bevels O by means of ring N. When contact takes place between
the end of lever D³ and the catch Q. Figure 3 the train arms are arrested and the
bevels O cannot revolve and consequently when bevel B is revolved in the direction
of arrow S the whole train of wheels is carried round, all maintaining the same
relative positions with regard to each other. The lower bevel R has a sleeve
attached R' through which the spindle A passes, wheel and sleeve running loosely
on spindle, on outside of sleeve R', I have a bush or cylinder T sliding vertically
upon feather keys but revolving with sleeve R', arms T1 and T2 pass downwards and
carry the tap T Figure 1 as shewn. Upon sleeve R' I fix sometimes spirals U₁
and UI use U to force the tap downwards into the hole. The spring U2 is a
lighter one and is used merely to support the weight of the cylinder T and its
attachments.
I sometimes dispense with the sliding cylinder T and carry the tap directly upon
the sleeve as shewn in B3 Figure 6. The operation is as follows.
insert the tap
in the hole to be tapped and start the drilling machine in direction of arrow S.
The outer end of lever D engages the catch Q Figure 3. The train is arrested
and the tap revolves in the same direction as the spindle A; when the tap reaches
the bottom of the hole or meets with any other obstruction beyond which it would
be unsafe to force it, the extra resistance causes the catch Q to press heavily
against the outer end D³ of lever D and compresses the spring E until the detent
operates as shewn in Figure 7. The end of lever D³ may now pass the catch Q
without contact, the motion of the tap and lower bevel is now arrested and the
train arms and friction ring N revolve at a reduced speed. The operator now
grasps the friction ring N and arrests its motion, when immediately reverse motion
is given to the lower bevel R and the tap is withdrawn. The operator releases the
detent H and the operation may be again repeated.
For large taps I employ a lever V with frictional pressure against the ring N
this I arrange as shewn by a small roller W which I force against the ring N by
lever W' and the rod X. The pressure of the hand of the attendant on lever W
forces roller W against ring N and draws friction band Y against opposite side of
ring NI may arrange this friction in any other well known manner. Sometimes I
dispense with friction and arrest ring N by a catch on lever instead of roller W
this catch engages in a hole in ring N or I lower a stop which I fix to the machine
carrying my apparatus, this stop engages a projection on ring N, I thus insert and
withdraw the tap without requiring reversing gear upon the drilling machine I have
described the foregoing as being attached to a vertical drilling machine for the
convenience of description only but I may use it horizontally or otherwise or
attach it to any suitable machine or I sometimes use my apparatus with suitable
attachment for screwing studs after having tapped the holes."
Sometimes I dispense with springs U₁ and U and use a lever for forcing down
the tap into the hole in this case I pivot the lever on a bush which revolves loosely
on the sleeve R¹ the inner end of lever pressing downwards against a suitable
collar on the cylinder T.
For different resistances I change the spring E or I may employ a set screw to
give to spring E a higher compression or I may prefer to move the spring E
nearer to or further from the fulcrum of lever D I use my apparatus with machines
that are provided with reversing gear as shewn in Figure 6 I attach the stop
lever D and detent arrangement as already described upon a disc y which is keyed
upon the spindle A³ and corresponds with the bevel wheel B. I dispense with
the bevel wheels and friction ring in this instance and I attach the catch Q'
Figure 6 to a second disc B³ which revolves loosely upon spindle A' as previously
described for bevel R and sleeve R'. The tap enters the hole as previously

page_text: described until the detent operates when the machine is reversed and the tap is
withdrawn by means of a pawl M² fixed upon the lower disc engaging into a
suitable rack N on the upper disc. This latter arrangement provides adjustable
resistance when spindle A revolves in one direction only if adjustable resistance
in both directions is required I may reverse and duplicate the disc Y upon the
spindle A' the spring and levers being on the underside as well as on top as already
described. I may use the foregoing epicyclic gear with well known releasing gear
instead of the spring arrangement described.
Having now particularly described & ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
1st. A screw tapping machine or attachment having an epicyclic train applied
to drive or to drive and reverse the tap or its equivalent substantially as and for
the purpose set forth and illustrated in the accompanying drawings.
2nd. A screw tapping machine having an epicyclic train together with a spring
adjusted catch releasing gear and reversing gear substantially as hereinbefore
described.
3rd. A screw tapping machine having the spring adjusted catch releasing gear
described hereinbefore and illustrated in the drawings.
4th. The screw tapping machine hereinbefore described and constructed as
illustrated in the drawings.
Dated this 15th day of October 1891.
J. W. HARTLEY.