Improvements in Ratchet Drills.
Year: 1891

page_text: Date of Application, 8th June, 1891
Complete Specification Left, 8th Mar., 1892-Accepted, 9th Apr., 1892
Improvements in Ratchet Drills.
I, GEORGE LOW EVATT of Port Hope, Province of Ontario, Dominion of
Canada, do hereby declare the nature of this invention to be as follows:-
The improved ratchet drill of this invention is adapted to drive the bit
continuously on both the forward and backward strokes of the handle and it is
constructed as follows:-
The stock which carries the bit has a shank mounted to turn in a hub formed
ceutrally in the bottom of a casing in or through which the said shank extends
centrally. On the lower end of the shank there is a collar which abuts against
the under side of the hub and the said shank is provided with two ratchet wheels
and a reduced end having an annular groove and extending through the cover
held on top of the casing. The latter is provided on its outside with a horizontally-
extending handle which is held to work the ratchet drill as hereinafter described.
The upper end of the stock also extends into a central hub formed on top of the
cover and provided at its outer end with threads or a fixed nut in which screws
a feed screw provided on its outer end with a triangularly-shaped head adapted
to abut against the fixed part located opposite the part to be drilled. On the
hub there is mounted to turn loosely a horizontally-extending handle carrying
a spring-pressed pawl engaging a ratchet wheel secured to the hub and serving
to turn the hub and its cover so as to screw up the feed screw. One of the
ratchet wheels of the shank is engaged by a spring-pressed pawl pivoted in the
handle of the casing while the other ratchet wheel is engaged by one, two, or
more spring pressed pawls pivoted in the lower face of a gear wheel mounted to
turn loosely on the shank. This gear wheel is in mesh with a number of pinions
journaled in an annular flange projecting from the bottom of the cover into the
casing. Each of the pinions carries a larger gear wheel in mesh with an internal
gear wheel formed on the inside of the casing. The cover, the casing, and the
stock are locked together by means of blocks which pass through recesses in the
hub into the annular groove formed in the upper reduced part of the shank of
the stock. Each of the blocks is provided with an outwardly-projecting pin
engaged by an L-shaped slot formed on a ring adapted to slip over the hub of the
cover to prevent the said blocks from becoming disengaged from the hub.
·
The operation is as follows:-When the several parts are set in position, the
operator holds the handle on the hub with his left hand and with his right hand
moves the handle on the casing backwards and forwards. At the forward move-
ment of the handle in the one direction the spring-pressed pawl on the handle
engages the teeth of the ratchet wheel and turns the stock and the bit in one
direction while on the backward movement this pawl glides over the teeth and at
the same time by means of the gear wheels and pinions a like movement is imparted
to the stock as the pawls of the loose gear wheel engage the other ratchet wheel.
Thus on the forward as well as on the backward stroke a forward movement is
imparted to the bit, it being understood that on the forward movement of said
handle the gear wheels roll over their respective gear wheels the pawls sliding
back on the ratchet. It is not necessary to hold either handle stationary at any
time. The only care required is that the one handle must be moved from the
operator while the other is being drawn toward him. The working of the drill

page_text: is not interfered with at any time but continues uninterruptedly until the desired
work is accomplished.
Dated this 8th day of June 1891
G. L. EVATT,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in Ratchet Drills.
⚫ I GEORGE Low EVATT of Port Hope, Province of Ontario, Dominion of
Canada do hereby declare the nature of this invention and in, what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement :-
The object of the invention is to provide a new and improved ratchet drill,
which is simple and durable in construction, very effective in operation, and
adapted to drive the bit continuously forward on both the forward and backward
strokes of the handle.
The invention consists of certain parts and details and combinations of the
same, as will be described hereinafter and then pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
Specification, in which similar letters of reference indicate corresponding parts in
all the figures.
Figure 1 is a side elevation of the improvement.
Figure 2 is a sectional side elevation of the same.
Figure 3. is a sectional plan view on the line of Figure 1.
Figure 4 is a sectional plan view on the line y-y Figure 2.
Figure 5 is an inverted plan view of one of the ratchet mechanisms.
Figure 6 is an enlarged sectional plan view on the line - Figure 2.
Figure 7 is an enlarged side elevation of the stock..
Figure 8 is an enlarged sectional plan view on the line w-w Figure 1 and
Figure 9 is a similar view on the line v-v Figure 2.
The improved ratchet drill is provided with a stock A in the lower end of
which is held the bit B. The stock A is provided with a shank C, mounted to
túrn in a hub D' formed centrally in the bottom of the casing D, in or through
which the said shank C extends centrally. On the lower end of the shank C is
formed a collar C¹ abutting against the under side of the hub D', and on the said
shank are also formed the two ratchet wheels C2 and C³, and a reduced end C¹,
provided with an angular groove C and extending through the cover F, on top of
the casing D. The latter is provided with a horizontally-extending handle E,
held by the operator to work the ratchet drill, as hereinafter more fully described.
The upper end of the stock A extends into a central hub F, formed on top of
the cover F and provided at its outer end with threads or a fixed nut G, in
which screws the feed screw H provided on its outer end with.a triangularly
shaped head H', adapted to abut against the fixed part located opposite the part
to be drilled by the bit B.
On the hub F is mounted to turn loosely the horizontally-extending handle 1,
carrying the spring-pressed pawl I engaging a ratchet wheel J, secured or formed
ou the hub F, and serving to turn the said hub and its cover F so as to screw
up the feed screw H when feeding the device.
The lower ratchet wheel C2 of the shank C is engaged by a pawl E¹, pressed.
on by a spring E2, and pivoted in the handle E of the casing D. The next ratchet
wheel C³ of the shank C is engaged by one, two or more spring-pressed pawls K',
pivoted in the lower face of a gear wheel K mounted to turn loosely on the
shank C. The gear wheel K is in mesh with a number of pinions L, journaled.in

page_text: an annular flange F. projecting from the bottom of the cover F into the casing D.
Each of the pinions L carries a larger gear wheel N, in mesh with an internal.
gear wheel O, formed on the inside of the casing D.
In order to lock the cover F, the casing D and the stock A. together, blocks P
are employed, which pass through recesses in the hub F into the annular groove C³
formed in the upper reduced part C of the shank C of the stock A.
Each of the
blocks P is provided with an outwardly-projecting pin. P, engaged by an L-shaped
slot Q formed on a ring Qadapted to slip over the hub F1 of the cover, to prevent
the said blocks from becoming disengaged from the hub F¹.
The operation is as follows.
When the several parts are in position, as illustrated in Figures 1 and 2, the
operator takes hold of the handle with his left hand, and with his right hand
moyes the handle E backward and forward. At the forward movement of the
handle E in the direction of the arrow a', (see Figure 6) the spring-pressed.
pawl E, by engaging a tooth of the ratchet wheel C, turns the stock A and the
bit B in the direction of the arrow a'. On the backward movement of the handle E
in the direction of the arrow the spring-pressed pawl El glides over the teeth
of the ratchet wheel C, and at the same time the internal. gear wheel O turns
the gear wheels N, which thus impart a similar movement to the pinions L, and
the latter engaging the gear wheel K, turn the latter in the direction of the
arrow a. This movement of the gear wheel K causes a like movement of the
stock A as the pawls of the said gear wheel engage, the ratchet wheel C³ of
the stock A, and its bit B. Thus on the forward as well-as, on the backward
stroke of the handle E, a forward movement is imparted to the bit B, it being
understood that on the forward movement of said handle, the gear wheels N and L.
roll over their respective gear wheels O and K, the pawls sliding back on the
ratchet C³.
It is not necessary to hold either handle stationary at any time, the only, care
required is, that the handle. I, be moved from the operator, while E is being
drawn toward him. The working of the drill is not interfered with at any time,.
but continues uninterruptedly until the desired work is accomplished.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is.
1. In a ratchet drill, the combination with a stock adapted to carry the bit and
provided with two ratchet wheels, of a handle casing in which the said stock is
pivoted to turn, and which is connected by a spring-pressed-pawl with one of said
ratchet wheels, and a gear wheel carrying spring-pressed pawls engaging the said
second ratchet wheel, the said gear wheel being connected by differential gear
wheels with the handle casing, substantially as shown and described. :
2. In a ratchet drill, the combination, with a stock adapted to carry the bit and
provided with two ratchet wheels, of a handle casing provided with an internal
annular gear wheel, a gear wheel mounted to turn loosely on the said stock
within the said casing, spring-pressed pawls carried on said gear wheel and adapted
to engage one of said ratchet wheels on the stock, and differential gear wheels
connecting the said gear wheel with the internal gear wheel on the said casing,
substantially as shown and described.
3. In a ratchet drill, the combination, with a stock adapted to carry the bit
and provided with two ratchet wheels, of a handle casing provided with an internal
annular gear wheel, a gear wheel mounted to turn loosely on the said stock
within the said casing, spring-pressed pawls on said gear wheel adapted to engage
one of said ratchet wheels on the stock, differential gear wheels connecting the
said gear wheel with the internal gear wheel on the said casing, and a spring-
pressed pawl on the said handle casing and engaging with the other of the said
ratchet wheels on the stock, substantially as shown and described.
4. In a ratchet drill, the combination, with a stock adapted to carry the bit and

page_text: provided with two ratchet wheels, of a handle casing provided with an internal
annular gear wheel and a pawl engaging one of said ratchet wheels, a cover adapted
to be held in a fixed position on top of the said casing, differential gear wheels
mounted to turn in the said cover and a central gear wheel mounted to turn
loosely on the said stock and in mesh with the. said differential gear wheels, and
also provided with spring pressed pawls engaging with the other ratchet wheel on
the stock, substantially as shown and described.
5. In a ratchet drill, the combination, with a stock adapted to carry the bit and
provided with two ratchet wheels, of a handle casing provided with an internal
annular gear wheel and a pawl engaging one of said ratchet wheels, a cover
adapted to be held in a fixed position on top of the said casing, differential gear
wheels mounted to turn in the said cover, a central gear wheel mounted to turn
loosely on the said stock and in mesh with the said differential gear wheels, and
also provided with spring-pressed pawls engaging with the other ratchet wheel on
the stock, a feed screw screwing in the said cover, and means substantially as
described, for turning the said cover, as set forth.
6. In a ratchet drill, the combination with a stock adapted to carry the bit
and provided with two ratchet wheels, of a handle casing provided with an internal
annular gear wheel and a pawl engaging one of said ratchet wheels, a cover adapted
to be held in a fixed position on top of the said casing, differential gear wheels
mounted to torn in the said cover, a central gear wheel mounted to turn loosely
on the said stock and in mesh with the said differential gear wheels; and also
provided with spring-pressed pawls engaging with the other ratchet wheel on the
stock, and means, substantially as described, for locking the said cover to the said
stock, and the said casing, substantially as shown and described.
7. The combination with the handle, casing, the rotary stock mounted therein,
extending at its upper end through the top of the casing and provided with an
annular groove C³, of the central hub F; into the lower end of which the said
grooved end of the stock projects, the blocks P extending through recesses in the
hub into the said groove C, and provided on their outer ends with pins P, the
ring Q on the hub provided with angle slots into which said pins project, the feed
screw extending through the upper threaded end of the hub, the ratchet wheel
on the hub, and the handle I having a pawl engaging the said ratchet wheel,
substantially as shown and described.
Dated this 8th day of March 1892.
G. L. EVATT,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.