IMPROVEMENTS IN POWER HAMMERS
Year: 1884

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for IMPROVEMENTS
IN POWER HAMMERS a communication to me from abroad by Gabriel Nicolas
Schoenberg, of Boulogne sur Seine, France Civil Engineer to be as follows:-
This invention relates to a system of power hammer, stamping machine or other
similar percussion apparatus in which the friction clutch forming the subject of
former Letters Patent No. 392 of 1883 is applied for raising the hammer. The
application of this clutch in percussion machines involves considerable modification
in their construction and working and enables the effects due to gravity to be
utilised in a more rational manner.
By the employment of the improved friction clutch gear before mentioned and
the novel arrangements in connection therewith, whether operated by hand or
power, if the weight to be raised repains at 130 lbs, a frictional contact of
about 120 lbs only is required "instead of 990 lbs, which is the mean of the
pressures hitherto employed for the same purpose.
.
It should moreover be remarked that as in the case of belts running upon
pulleys, this pressure of 120 lbs decreases in proportion to the increase of the
velocities in inverse direction of the two contact surfaces, that is to say the greater
is the fall and consequently the greater is the velocity on impact the less pressure
need be exerted to raise the weight at the moment of striking. Another advantage
of this system of plane friction surfaces is that a movement of a fraction only of a
millimetre, suffices for engaging and disengaging, as is fully explained in the former
patent referred to.
4.
It only remains to state that with the generality of percussion tools of the kind,
there exists no practical means of rectifying the play caused by concussion and the
vibration resulting from the contact of metallic surfaces, and which play imme-
diately it is produced, creates horizontal components which cause the tools between
which the shaping is effected, to continually vary in position, whereas the tools
need above all to have perfect rigidity, combined with facility of regulation, if it is
desired to produce with rapidity, perfect forms free from variation.
All the above objections are obviated in the machine which I will now proceed
to describe with reference to the drawings annexed to this specification, The

page_text: apparatus is represented in general arrangement and principal details by the
figures A to K, but merely by way of example.
Figure A is a general face view, figure B a corresponding side elevation figure C
a section of one of the guides taken across the packing pieces, figure D is an eleva-
tion of the same part of the guides, Figure E is a sectional plan of the upper part
of one of the guides, figure F is a detail in the mechanism, figure G is a face view
on a larger scale of the friction clutch mechanism mounted at the upper part of the
machine, figure H is a corresponding side view, figure I is an elevation on a larger
scale of the friction clutch gear, figure J is a plan of same, figure K is a detail
elevation on a larger scale of the hand gear for actuating the hammer. In all
these figures, the same letters of reference denote the same parts.
The
I will first describe the mode of absorbing the excessive metallic vibrations due
to this velocity of the monkey at the moment of, impact and then the method of
regulating or rectifying the play of the monkey at any point of the guides imme-
diately it occurs In this machine, the monkey is guided as usual by two, angular
guide bars a a whose lower ends are fixed in clamps in the base 6 of the machine
(figures A B C D) packing strips of leather folded angularly and covered with a
number of very thin plates of sheet iron of the same form as the leather as shown
at d figures C and D, being applied around the ends of the guide bars, which are
clamped in place by the angular filling block e figure C, (also furnished at both
ends with strips of leather and throughout the whole length of the recess, both
for the guides a as well as the filling e as may be seen in figures D, E, F) which
is held in place by the cover f figures A, B, C provided with lugs through which
are passed cotters and screw bolts as indicated in the three figures, and which serve
to firmly clamp the bottom end of the guides in their sockets. The upper ends of
the guides are reduced to one half their thickness as shown in figure E in order to
serve as a support for the head of the framing in which they are fitted by means
of packing pieces of leather and sheet iron of the same form and thickness as those
for the base and by a cap c figures E and F with pieces of leather superposed and
rivetted and secured by screw bolts as shown in figures F and H. The distance
between the guides can be easily regulated by simply adding to or reducing the
number of thin sheet iron plates, without removing the leather packing.
guides are held rigidly in position by means of four adjustable steadying pieces g. 9, II
figure A faced with leather, leather washers being also inserted beneath the nuts of
the bolts passing through the standards h h. All these elastic surfaces are reduced
by the pressure, to the condition of isolation, for absorbing all excessive vibration,
caused by the blows of the hammer, but only for a velocity on impact not exceeding
16 feet. In this manner once the adjustment is effected, it will be maintained
for a length of time without any sensible amount of wear of the sliding surfaces
and immediately the wear becomes appreciable it is simply necessary to slacken the
cover plates at top and bottom of one of the guides only, and remove one or two
of the sheet iron packing strips at top and bottom and then to tighten up the
covers again as well as the two angular steadying pieces j, j on the same side. In
this manner a fresh adjustment is quickly obtained which will prevent the
breakages and dislocations which would in the old system have resulted from
shocks due to the contact of metallic surfaces, and also to the want of any means
of taking up the wear resulting from the absence of the elasticity necessary to
retain the original adjustment of the parts as long as possible. By sufficiently.
recessing the parts one in the other, regard being had to the weight of the hammer,
the leather after being once pressed will last for an indefinite time and remain
consequently in the condition of an isolating body between the metallic surfaces
upon which the hammer continually acts by the vibration which it causes.
Referring to figures C and D it will be seen that the original form of the portions
of the guide rods which are held in the socket may be successively reduced as the
guides become worn without altering the conditions of absorption and adjustment.
The dotted lines in figure C show the alternate form if after prolonged wear each
1.

page_text: guide had been successively advanced to the extent of wear thus proving that the
system retains its isolating and adjusting properties until the guides are completely
worn out.
Standards. In this machine the cast iron standards h h figures A and B are fixed
both to the base b and to the top plate ii whereby they both consolidate the entire
framing of the machine and also serve in conjunction with said plate to carry the
parts employed to work the haminer, whether by hand or power. At the upper part
of these standards are fixed two bearings u¹ u¹ (figures A and B) in which is
mounted a shaft v¹ (figures HA, B) having a central crank a connected to the
hooks by a pin y¹ figure A, and having at its left hand end a crank arm a
figure 8 with counterbalance to which is attached a connecting rod b descending
to the lower part of the machine where it is operated either by hand or foot for
releasing the monkey and letting it drop. To the right hand standard at dª
figure B is jointed one end of the toggle c₁ (figures A and B) whose other end is
connected to lever e² by means of, similar adjustments to those indicated at the
lower part of lever m figure I; the centre joint pin of the toggle, whose extent of
motion is indicated in dotted outline in figure A is connected with the long vertical
rod figures A, B, F, The rod f extends upwards above the joint and terminates
in a bolt figure F which moves up and down in a guide screwed to standard h
as shown in figure B. The rod has enlargements below the joint between which
and the guides h² on the standards, spiral springs are compressed (figures A B).
The bottom end of the rod f is enlarged at figure K to receive the screwed
socket and the corresponding screwed hand nut m' as shown in figures A, B, K,
the whole being retained by a cotter n². Upon this screwed socket k² which is
prevented from turning on the rod by a key way of in the enlargement is fitted
a grooved sleevecp which is caused to travel up & down upon said socket by
rotating the hand nut m². A fork engages in the groove of sleeve p³ the tail end
of said fork embracing and being bolted to the lever q³ (figures A and K) which
is pivoted at 8 to a bracket cast on the standard, the other end being directly in
the path of the tappet t fixed adjustably by bolts u² in a groove in the monkey k¹.
The tappet should always strike the end of lever q when the tools carried by
the monkey are in contact at the end of the drop, and it is desired to throw the
clutch into gear automatically. The rod f' extends below the cotter n² and is
threaded at the end to receive a nut v screwing against the cottar x which is
embraced by lever y pivoted at one end in a bracket a³ upon the standard, the
other end being connected by a rod b³ to the hand lever pivoted at d³ to a
stud e³ on the base b for throwing the clutch into gear by hand when it is not
desired to work the hammer automatically. The two standards also carry in pillow
blocks ƒ³ (figures A B the horizontal driving shaft g³ having fast and loose
pulleys ³ and a pulley by which the motion is transmitted to the friction clutch
pulley 3
In this arrangement it has been possible to place the plate carrying the friction
gear at the upper part of the machine without affecting its stability by limiting
the height of fall and more especially the velocity on impact, for the size of
hammer for which this class of machine is intended I would here again remark
that to this velocity on impact, are due the destructive effects produced in all
machines having the parts in metallic contact, which are transmitted to all the
adjacent parts and this it is which has led to the increase to a very great extent
of the means for preventing this destructive effect in applying the foregoing
arrangements to long drops with hammers of relatively small weight.
The plate iii the form of which is seen in figures A B C is more particularly
intended to establish connection between the bearing K (ɓigures A and G) and the
abutment l.
Figures I and J show the mechanism connected with the gear above described
for throwing the clutch into gear. The abutment and its mechanism applied for
adjusting the pressure and compensating for wear of the friction surfaces, is
described in the former Patent for the friction coupling before referred to,

page_text: The arrangement shown in figures I J is specially designed for this type of drop-
hammer as applied to the raising of weights by friction. It is composed of a lever m
figures A B, I J, whose ends work between hardened steel bushes n n having
adjusting screws oo whereby the oscillation of the lever may be transmitted with
an accuracy absolutely indispensable as the motion necessary to throw the friction
surfaces in and out of gear is limited to a fraction of a millimetre.
The upper or, thrust rod n passes through the support p and is screwed into a
cross head until its extremity, which is pivot shaped and hardened, abuts against
pivot fitted and cottered in the end of the shaft s which carries the cast iron
friction disc represented in dotted lines in figure A and described in the
specification of the former patent for the friction coupling before referred to. The
cross head q is connected by screw rod t t to a second cross head u pressing against
a flange on pivot so that if after having screwed the thrust rod into the cross
head there should be the slightest play between the two hardened pivot points, it
may be rectified by means of the nuts on the rods t. By this arrangement, the
shafts, the flanged pivot and the friction disc in connection therewith are free to
turn in the bearing and cross bar u without allowing the slightest play between
the parts u and, or between the rotating and stationary pivots or between the
latter and the lever m.
'.
The plate i as will be seen establishes perfect solidarity of the mechanism placed
between them and an additional advantage derived from the arrangement is
the capability of applying the pressure by means of pivots thus avoiding all
intermediate deflection, play and friction of the transmitting mechanism. Upon
the shaft v (figures A and G) is keyed a central pulley W to which the strap x
(figures A and B) is attached by means of clamping plates also as described in my
said former patent. Upon two of the bearings of shaft v, which are connected to
the upper clamps of the guides as clearly shown in figure H, is fixed a double
frame xx (figure GH A and B) resting thereon, whose upper ends are connected
by the cross frame and tied to the plate i by the struts f¹
.
Each frame has a slot,b and a circular cavity c¹ to receive a spiral spring or
blocks of india rubber with intervening discs of sheet iron as shown in figures G H.
In the slots b¹ are fitted to slide bearings d' having guide stems projecting from
their upper and undersides the latter passing down through the elastic material
which is compressed by the metal disc e¹ while the former pass up through the
top cross frame a' which forms a guide therefor.
The bearings carry the shaft of a guide pulley y over which passes the strap
attached to drum W by which the monkey is raised. Upon the plater and in rear
of the bearings are two other circular recesses g¹ (figures E F G, H) also containing
spiral or indiarubber springs compressed to an initial pressure by means of glands ¹
as shown in the various figures adjusted by screws and nuts and pressing upon
a central disc provided with guide rods projecting above and below it the former
passing through the springs into the metal, and the latter traversing the glands h.
On the ascent of the monkey k¹ figures A, B, G, H the bosses ¹ thereon strike
against the rods and compress the springs. The upper rod which is in contact
with the lever m¹ (figures A, F) thereupon raises the latter compresses the spirál
spring n rocks the arm o¹ which is connected by shaft p¹ (figure B) to the arın q¹
which draws back the horizontal bolt r¹ figure F whose motion may at any time
be kept retracted by attaching to the arm o¹ or other crank in connection with
shaft p¹ a chain or wire, indicated in dot and dash lines in figures A and F and
terminating in a ring which is hooked to the standard h.
.
The plate i is also provided on its under surface and a little in advance of the
strap with two ears 81, in which is mounted a rock spindle to whose ends are fixed
two hooked arms t¹¹ (figures A G H) which are oscillated by being connected by
the shaft before described.
Monkey. The monkey k¹ is of cast iron and may be varied in form as desired. To
connect it to the, strap, it is attached by means of, a dove-tailed joint to a block of
metal s figures A and G provided with a pair of knuckles through which passes a

page_text: pin m³ whose ends project as shown in figures G and H for the suspension hooks
t', t (figures A and G) to take hold of and on which the monkey rests under the
initial pressure of the springs above when it is desired to suspend the fall of the
hammer.
The pin m³ is the joint pin connecting the block to a link n³ (figures A and
B) upon which are lapped a number of leather strips stitched together and built.
up of the rounded form shown, and around which the lower end of the strap is
passed and secured by screw studs as shown in figure A.
Two very great advantages are derived from this arrangement the first is that
the length of the bight formed by the end of the strap is increased and secondly
that an elastic cushion is provided at this point of the strap, where it is subject to
considerable strain, when the monkey is suddenly raised by the friction gear, or
when it is arrested at any point of its fall. It will be seen in figure A that the
strap, whose breadth is adapted to the weight to be lifted, may gradually increase
in breadth from the point of attachment, upwards to its opposite end, thus
affording a secure connection to the winding drum W.
Automatic gear.
..
The automatic friction clutch gear for raising the monkey is adjusted by the
hand lever figure B which is free to oscillate when the horizontal bolt figure
F has been held retracted as above stated. By means of this lever c³ the monkey
is slightly raised and then allowed to fall the tappet 2 figure K being at same
time adjusted until brought into sufficient contact with the end of lever q³ in order
that the latter inay after one or two trials, substitute its action for that of lever c³
the latter being left connected or not "with lever q3 by the cotter n which is
inserted before commencing the adjustment.
If
This done, the monkey is now raised by (acting on the hand lever, to its full
height, after which the hand nut m² figure K' may be adjusted so as to raise or
lower lever q² and thus regulate the intensity of the blow; percussive effects of any
force desired may thus be obtaind at will without the swage of tool remaining in
contact with the article being shaped. When the ascent of the monkey has been
thus made dependent on the action of lever q2 and the friction clutch the
horizontal bolt is again put in action, as are also the holding-up looks t¹ (if the
continued motion action of the hammer is not required).
"1
In either case it will be observed that the monkey in rising at its full velocity
should at every stroke strike the rods t¹ t¹ and store up initial force until the
moment when the lever m¹ figure F lifted by the blow with 'draws 'the horizontal
bolt 1 and allows the vertical bolt g² to be raised by the action of the springs,
figure B, thus throwing the friction clutch out of gear. As all the changes of
motion of the monkey require to be performed very quickly, recourse is had to a
guide pulley y figures A, B, G mounted on spring bearings in order to attenuate the
shock and strain, which combined with the modes of attachment and winding of
the strap as herein described, and as described in the former patent before referred
to, ensures great advantages.
This system of hammer is so arranged as to be capable of regulating the initial
force and thereby permit of instantly restoring the full extent of motion to the
moving parts without the grave objection of bringing entirely upon the strap i
incessant concussions produced during the working.
.
1.1
TI
1. T
the

page_text: I, ALEXANDER MELVILLE CLARK, of the firm of. A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN POWER HAMMERS" (a communication to me from abroad by Gabriel Nicolas
Schoenberg of Boulogne-sur-Seine, France, Civil Engineer, and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:—
This invention relates to a system of power hammer, stamping machine or other
similar percussion apparatus in which the friction clutch forming the subject of
former Letters Patent No 392 of 1883 is applied for raising the hammer. The
application of this clutch in percussion machines involves considerable modification
in the construction and working and enables the effects due to gravity to be utilised
in a more rational manner. By the employment of the improved friction clutch
gear before mentioned and the novel arrangements in connection therewith, whether
operated by hand or power, if the weight to be raised remains at 130 lbs, a frictional
contact of about 120 lbs only is required instead of 990 lbs, which is the mean of
the pressures hitherto employed for the same purpose.
It should moreover be remarked that as in the case of belts running upon pulleys,
this pressure of 120 lbs decreases in proportion to the increase of the velocities in
inverse direction of the two contact surfaces, that is to say the greater is the fall
and consequently the greater is the velocity on impact the less pressure need be
exerted to raise the weight at the moment of striking, Another advantage of this
system of plane friction surfaces is that a movement of a fraction only of a
millimetre, suffices for engaging and disengaging, as is fully explained in the former
patent referred to.
It only remains to state that with the generality of percussion tools of the kind,
there exists no practical means of rectifying the play caused by concussion and the
vibration resulting from the contact of metallic surfaces, and which play immediately
it is produced, creates horizontal components which cause the tools between which
the shaping is effected, to continually vary in position, whereas the tools need above
all to have perfect rigidity, combined with facility of regulation, if it is desired to
produce with rapidity, perfect forms free from variation.
All the above objections are obviated in the machine which I will now proceed
to describe with reference to the drawings annexed to this Specification. The
apparatus is represented in general arrangement and principal details by figures A
to K, but merely by way of example.
Figure A is a general face view, figure B a corresponding side elevation figure C
a section of one of the guides taken across the packing pieces, figure D is an
elevation of the same part of the guides, figure E is a sectional plan of the upper
part of one of the guides, figure F is a detail in the mechanism, figure G is a face
view on a larger scale of the friction clutch mechanism mounted at the upper part
of the machine, figure H is a corresponding side view, figure I is an elevation on a
larger scale of the friction clutch gear, figure J is a plan of same, figure K is a

page_text: detail elevation on a larger scale of the hand gear for actuating the hammer. In all
these figures, the same letters of reference denote the same parts.
I will first describe the mode of absorbing the excessive metallic vibrations due
to this velocity of the monkey at the moment of impact and then the method of
regulating or rectifying the play of the monkey at any point of the guides, imme-
diately it occurs. In this machine the monkey is guided as usual by two angular
guide bars a a whose lower ends are fixed in clamps in the base b of the machine
(figures A B. C, D), packing strips of leather folded angularly and covered with a
number of very thin plates of sheet iron of the same form as the leather as shown
at d figures C and D, being applied around the ends of the guide bars which are
clamped in place by the angular filling block e figure C, (also furnished at both ends
with strips of leather and throughout the whole length of the recess, both for the
guides a as well as the filling e as may be seen in figures D, E, F) which is held in
place by the cover of figures A B, C provided with lugs through which are passed
cotters and screw bolts as indicated in the three figures, and which serve to firmly
clamp the bottom end of the guides in their sockets. The upper ends of the guides
are reduced to one half their thickness as shown in figure E in order to serve as a
support, for the head of the framing in which they are fitted by means of packing
pieces of leather and sheet iron of the same form and thickness as those for the
base and by a cap c figures E and F with pieces of leather superposed and rivetted
and secured by screw bolts as shown in figures F and H. The distance between
the guides can be easily regulated by simply adding to or reducing the number of
thin sheet iron plates without removing the leather packing. The guides are held
rigidly in position by means of four adjustable steadying pieces g. 9, 9, 9 figure A
faced with leather, leather washers being also inserted beneath the nuts of the bolts
passing through the standards h h. All these elastic surfaces are reduced by the
pressure, to the condition of isolation, for absorbing all excessive vibration, caused
by the blows of the hammer, but only for a velocity on impact not exceeding 16 feet.
In this manner once the adjustinent is effected, it will be maintained for a length
of time without any sensible amount of wear of the sliding surfaces and immediately
the wear becomes appreciable it is simply necessary to slacken the covering plates
at top and bottom of one of the guides only, and remove one or two of the sheet
iron parking strips at top and bottom and then to tighten up the covers again as
well as the two angular steadying pieces j, j, on the same side. In this manner
a fresh adjustment is quickly obtained which will prevent the breakages and
dislocations which would in the old system have resulted from shocks due to the
contact of metallic surfaces and also to the want of any means of taking up the
wear resulting from the absence of the elasticity necessary to retain the original
adjustment of the parts as long as possible. By sufficiently recessing the parts one
in the other, regard being had to the weight of the hammer, the leather after being
once pressed will last for an indefinite time and remain consequently in the con-
dition of an isolating body between the metallic surfaces upon which the hammer
continually acts by the vibration it causes. Referring to figures C and D it will be
seen that the original form of the portions of the guide rods which are held in the
socket may be successively reduced as the guides become worn without altering
the conditions of absorption and adjustment. The dotted lines in figure C show the
alternate form if after prolonged wear each guide had been successively advanced
to the extent of wear, thus proving that the system retains its isolating and
adjusting properties until the guides are completely worn out.
Standards. In this machine the cast iron standards hh figures A and B are
fixed both to the base band to the top plate ii whereby they both consolidate
the entire framing of the machine and also serve in conjunction with said plate to
carry the parts employed to work the hammer whether by hand or power. At the
upper part of these standards are. fixed two bearings u¹ u¹ (figures A and B) in
which is mounted a shaft v (figures H, A, B) having a central crank ³ connected
to the hooks t' by a pin y' figure A, and having at its left hand end a crank arm. a
(figure 8) with counter-balance, to which is attached a connecting rod bª descending

page_text: to the lower part of the machine, where it is operated either by hand or foot for
releasing the monkey and letting it drop. To the right hand standard at d²
figure B is jointed one end of the toggle c² (figures A and B) whose other end is
connected to lever e2 by means of similar adjustments to those indicated at the
lower part of lever m figure I; the centre joint pin of the toggle, whose extent of
motion is indicated in dotted outline in figure A, is connected with the long vertical
rod f' figures A, B, F..
The rod f extends upwards above the joint and terminates in a bolt j figure F
which moves up and down in a guide screwed to a standard has shown in
figure B. The rod has enlargements below the joint between which and the
guides on the standards, spiral springs are compressed (Ggures A B). The
bottom end of the rod f? is enlarged at 12 figure K to receive the screwed socket s
and the corresponding screwed hand nut me as shown in figures A, B, K, the whole
being retained by a cotter n². Upon this screwed socket which is prevented
from turning on the rod by a key way o' in the enlargement 13, is fitted a grooved
sleeve which is caused to travel up and down upon said socket by rotating the
hand nut m². A fork engages in the groove of sleeve p³, the tail end of said fork
embracing and being bolted to the lever q' (figures A and K) which is pivoted
at s² to a bracket cast on the standard, the other end being directly in the path
of the tappet t' fixed adjustably hy bolts u in a groove in the monkey k¹.
The tappet should always strike the end of the lever q2 when the tools carried by
the monkey are in contact at the end of the drop, and it is desired to throw the
clutch into gear automatically. The rod fi extends below the cotter n², and is
threaded at the end to receive a nut screwing against the collar x3 which is
embraced by a lever y pivoted at one end in a bracket a³ upon the standard, the
other end being connected by a rod b³ to the hand lever c³ pivoted at d³ to a stud e³
on the base b for throwing the clutch into gear by hand when it is not desired
to work the hammer automatically. The two standards also carry in pillow
blocks (figures A B) the horizontal driving shaft g³ having fast and loose
pulleys and a pulley by which the motion is transmitted to the friction clutch
llow 3
In this arrangement it has been possible to place the plate carrying the friction
gear at the upper part of the machine without affecting its stability by limiting the
height of fall and more especially the velocity on impact, for the size of hammer for
which this class of machine is intended I would here again remark that to this
velocity on impact, are due the destructive effects produced in all machines having
the parts in metallic contact, which are transmitted to all the adjacent parts and
this it is which has led to the increase to a very great extent of the means for
preventing this destructive effect, in applying the foregoing arrangements to long
drops with hammers of relatively small weight.
The plate iii the form of which is seen in figures A, B, C, is more particularly
intended to establish connection between the bearing K (figures A and G) and the
abutment l.
Figures I and J show the mechanism connected with the gear above described
for throwing the clutch into gear. The abutment and its mechanism applied
for adjusting the pressure and compensating for wear of the friction surfaces, is
described in the former Patent for the friction coupling before referred to.
The arrangement shown in figures I J is specially designed for this type of drop
hammer as applied to the raising of weights by friction.
It is composed of a lever m figures A B, I J, whose hands work between hardened
steel bushes n n having adjusting screws o o whereby the oscillation of the lever
may be transmitted with an accuracy absolutely indispensable, as the motion
necessary to throw the friction surfaces in and out of gear is limited to a fraction
of a millimetre,

page_text: The upper or thrust rod n passes through the support pand is screwed into a
cross head q until its extremity, which is pivot shaped and hardened; abuts against
a pivot fitted and cottered in the end of the shafts which carries the cast iron
friction disc represented in dotted lines in figure A and described in the specification
of the former patent for the friction coupling before referred to. The cross head q
is connected by screw rods t t to a second cross head u pressing against a flange on
pivot, so that if after having screwed the thrust rod n into the cross head q there
should be the slightest play between the two hardened pivot points, it may be
rectified by means of the nuts on the rods t. By this arrangement, the shaft 8, the
flanged pivot r and the friction disc in connection therewith are free to turn in the
bearing k and cross bar u without allowing the slightest play between the parts u
and r, or between the rotating and stationary pivots or between the latter and the
lever m.
The plate as will be seen establishes perfect solidarity of the mechanism placed
between them and an additional advantage derived from the arrangement is the
capability of applying the pressure by means of pivots, thus avoiding all inter-
mediate deflection, play and friction of the transmitting mechanism. Upon the
shaft (figures A and G) is keyed a central pulley W to which the strap x (figures A
and B) is attached by means of clamping plates also as described in my said former
patent. Upon two of the bearings of shaft v, which are connected to the upper
clamps of the guides as clearly shown in figure H, is fixed a double frame xx
(figures G H A and B) resting thereon, whose upper ends are connected by the cross
frame a and tied to the plate i by the struts f¹.
Each frame has a slot b¹ and a circular cavity c¹ to receive a spiral spring
or blocks of india rubber with intervening discs of sheet iron as shown in
figures G H.
In the slots b¹ are fitted to slide bearings d' having guide stems projecting from
their upper and undersides, the latter passing down through the elastic material
which is compressed by the metal disc e¹ while the former pass up through the top
cross frame a¹ which forms a guide therefor.
The bearings carry the shaft of a guide pulley y over which passes the strap
attached to drum W by which the monkey is raised. Upon the plate and in rear
of the bearings are two other circular recesses g¹ (figures E F G H) also containing
spiral or india rubber springs compressed to an initial pressure by means of
glands has shown in the various figures adjusted by screws and nuts and pressing
upon a central disc provided with guide rods projecting above and below it,
the former passing through the springs into the metal, and the latter traversing the
glands h¹.
On the ascent of the monkey k¹, figures A, B, G, H, the bosses ¹¹ thereon strike
against the rods and compress the springs. The upper rod which is in contact
with the lever m¹ (figures A F) thereupon raises the latter, compresses the spiral
spring n', rocks the arm o¹ which is connected by shaft p¹ (figure B) to the arm q¹
which draws back the horizontal bolt (figure F) whose motion may at any time
be kept retracted by attaching to the arm o¹ or other crank in connection with
shaft pl, a chain or wire, indicated in dot and dash lines in figures A and F, and
terminating in a ring which is hooked to the standard h.
The plate i is also provided on its under surface and a little in advance of the
strap, with two ears 8¹, in which is mounted a rock spindle, to whose ends are
fixed two hooked arms t¹t (figures A G H) which are oscillated by being connected
by the shaft v¹ before described.
Monkey. The monkey 'is of cast iron and may be varied in form as desired:
To connect it to the strap it is attached by means of a dovetailed joint to a block
of metal 3 (figures A and G) provided with a pair of knuckles through which
passes a pin m³, whose ends project as shown in figures G and H, for the suspension
hooks t¹¹ (figures A and G) to take hold of and on which the monkey rests under
the initial pressure of the springs above when it is desired to suspend tlie fall of
the hammer.

page_text: of the rounded form shown, and around which the lower end of the strap is passed
and secured by screw studs as shown in figure A.
Two very great advantages are derived from this arrangement the first is that
the length of the bight formed by the end of the strap is increased and secondly
that an elastic cushion is provided at this point of the strap, where it is subject to
considerable strain, when the monkey is suddenly raised by the friction gear, or
when it is arrested at any point of its fall. It will be seen in figure A, that the
strap, whose breadth is adapted to the weight to be lifted, may gradually increase
in breadth from the point of attachment, upwards, to its opposite end, thus affording
a secure connection to the winding drum W.
Automatic gear.
The automatic friction clutch gear for raising the monkey is adjusted by the
hand leveres (figure B) which is free to oscillate when the horizontal bolt 1
(figure F) has been held retracted as above stated. By means of this lever c³, the
monkey is slightly raised and then allowed to fall, the tappet t' figure K being at
same time adjusted until brought into sufficient contact with the end of lever q² in
order that the latter may after one or two trials, substitute its action for that of
lever c³, the latter being left connected or not with lever q² by the cotter n³, which
is inserted before commencing the adjustment.
This done, the monkey is now raised to its full height, by acting on the hand
lever, after which the hand nut m² figure K may be adjusted so as to raise or lower
lever q and thus regulate the intensity of the blow; percussive effects of any force
desired may thus be obtained at will without the swage or tool remaining in
contact with the article being shaped.
When the ascent of the monkey has been thus made dependent on the action of
lever q and the friction clutch, the horizontal bolt 1 is again put in action, as are
also the holding up hooks t¹ (if the continued motion of the hammer is not
required).
In either case it will be observed that the monkey in rising at its full velocity
should at every stroke, strike the rods and store up initial force until the
moment when the lever m¹ figure F lifted by the blow withdraws the horizontal
bolt and allows the vertical bolt g² to be raised by the action of the springs j³, j
(figure B) thus throwing the friction clutch out of gear. As all the changes of
motion of the monkey require to be performed very quickly recourse is had to a
guide pulley y (figures A B G) mounted on spring bearings in order to attenuate
the shock and strain, which combined with the modes of attachment and winding
of the strap as herein described and as described in the former patent before
referred to, ensures great advantages.
This system of hammer is so arranged as to be capable of regulating the initial
force and thereby permit of instantly restoring the full extent of motion to the
moving parts without the grave objection of bringing entirely upon the strap, the
incessant concussions produced during the working.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
1st In a drop hammer or monkey as herein described, the improved clutch formed
of leather coils having their edges in frictional contact with a metal plate and
enclosed in a casing as described in my former patent N° 392 of 1883 before
referred to, in combination with guide standards around whose ends are applied
strips of leather, wood and thin sheet iron for the purpose of absorbing vibration.
2nd In a drop bammer or monkey as described, the construction and mode of
mounting the upper and lower ends of the guide standards in the base b and cover f
figures A B C respectively, with sufficient play to receive a packing of leather and

page_text: sheet iron combined, the said guides being readily adjusted by simply adding to or
reducing the number of the thin sheet iron plates and the accessory parts of the
guides being also provided with leather packings for the purpose of absorbing
vibration as described.
3rd In a drop hammer or monkey provided with the friction gear described, the
lever m with adjustable pivots n for putting the friction clutch in and out of action
through the cross head and pivot upon the end of the shaft carrying the
friction disc, as described with reference to figures A. B, I J.
4th In a drop hammer or monkey, the springs or elastic bodies composed of
indiarubber blocks separated by sheet iron discs, which are compressed by the
ascent of the hammer, the resulting pressure serving to assist the blow, and the
rods for acting on the horizontal bolt 1 (figure F) for connecting or discon-
necting the hand lever c³ (figure B) which regulates the automatic action of the
hammer by connecting the same with the friction gear.
5th In a drop hammer or monkey, the mode of attaching the monkey to the strap
by means of a block of metal 3 (fig G) provided with a pair of knuckles through
which passes a pin m³ upon whose projecting ends the suspension hooks t¹ of the
monkey rest, said pin m³ being connected to a link n³ (figure B) upon which are
lapped a number of leather strips stitched together as described for the purpose
specified.
6th In a drop hammer or monkey, in which the monkey is suspended by a strap
attached as described, the guide pulley y over which said strap passes having
bearings sliding in a frame b¹ and provided on the underside with a guide stem
passing down through indiarubber blocks with intervening discs of sheet iron
contained in cavity c¹ as described with reference to figure H.