Year: 1887

page_text: United States of America, Manufacturer.
I, ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex, M.I.M.E.
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:
This invention relates to that class of drop hammers in which the hammer is raised
by some flexible connection as a strap band or belt alternately engaged and released
from pressure by friction pulleys the hammer head or drop falling by the action of
gravity to apply its living force in a blow upon material to be worked or upon dies &c.
for working such material.
The improvement has for its general object the supply of a gripping and releasing
mechanism more certain and reliable in its action upon the flexible connections of this
class of haminers than has hitherto been attained and more particularly in use for the
drop hammer patented to my correspondent September 28th 1886 in the United
States and numbered 350007 experience having shown that, with this drop hammer
as well as with others that preceded it the release of the belt is so irregular that the
weight sometimes falls before such release is perfectly effected, thus not only retarding
the velocity of fall of the hammer-head and retaining its efficiency but violently
Of course
straining the belt sometimes to the point of actually tearing it asunder.
this strain upon the belt also adds to the wear of the gripping and releasing mechanism
and these defects combine to render a more positive release of the flexible connection
of such hammers extremely desirable.
In my correspondent's former invention the driving grasp of the friction pulleys on
the belt was effected partly by the weight of the hammer head hanging from one of
the pulleys but chiefly by the action of gripping and releasing devices which acted to
positively force or clamp the pulleys together which system was not found to be
sufficiently quick or sensitive in the releasing action and was hence liable to retard
the fall of the hammer or tear the belt. In the present invention however the driving

page_text: grasp of the pulleys on the belt is effected solely by the weight of the hammer itself
which hangs by its attached belt from a pendulous or movable driven pulley which is
thereby forced against the fixed driving pulley between which the belt passes both of
said pulleys being geared together. A wedging or separating device is arranged to
relax or separate the pulleys so as to lift the pendulous or gravitating pulley away
from the fixed pulley, and thus allow the hammer to fall free and this wedging or
separating device is operated by tappets struck by the hammer head at each end of
the stroke. The present invention therefore consists mainly in the features above
outlined and in the special construction and arrangement of the friction pulleys and
the separating device as hereinafter fully set forth.
Figure 1 is partly a section and partly a side elevation of a drop hammer comprising
the improvement, the hammer head being in the position of rest which it may occupy
as well when the pulleys of the gripping and releasing mechanism are in motion
(indicated by the arrows in the figure) as when they also are at rest which will
subsequently more plainly be shown.
Figure 2 is a similar sectional side elevation showing positions of parts when the
hammer-head is rising preparatory to striking its blow.
Figure 3 is a partial sectional and side elevation showing the hammer head raised
nearly to the point of release and illustrating the action of certain parts of the
mechanism preliminary to the positive release of the strap or belt.
Figure 4 is a front view of a part of the machine, and Figure 5 is a section on the
line in Figure 3.
A Figures 1 and 2 is the base or anvil support and from this base rise two guides B
for the hammer head or drop in the usual manner. The hammer-head is lettered C.
The flexible connection (in this instance a belt or strap) is lettered D. It is attached
to the hammer head at E in the usual manner. To the sides of one of the guides Bis
pivoted a pawl lever F, which engaging recessed teeth on the hammer head holds the
latter from moving when so engaged and which by means of a link a connecting it
with a treadle may be disengaged from the hammer head to allow the latter to fall."
The parts thus lettered and referred to being all old and well known in the art will
require no further detailed description.
It is in the construction and operation of the mechanism above these parts and in
means whereby it is controlled by the movement of the hammer head that the present
invention wholly consists.
The strap or belt D extends up over a pulley G and down between said pulley and
another pulley G₁ the unattached end of the belt below said pulleys hanging free.
These pulleys are of equal diameters and their shafts h h to which they are keyed are
geared together by spur gears H H¹ which arrangement secures equal circumferential
velocity in the perimeters of the pulleys. To the shaft h is also keyed a driving
pulley I at the end opposite the gear H³.
The faces of the pulleys G G which when the haminer head is raised by the belt
firmly grip or clamp the latter between them are by mechanism about to be described
slightly moved away from each other to release the belt from such clamping action
when the hammer is desired to fall and deliver its blow the teeth of the spur gears HH'
being sufficiently deep to permit this motion without unmeshing with each other.
The pulleys G G gears H H and shafts h¹ are all supported by bearings g g
formed in or on or supported by a stout frame K which may be mounted. on top. of
the guides B or may be attached to overhead supports or floor beams L by any
suitable means as shown and in proper relation with the hammer head that is to say
in such relation that the end of the belt or strap attached to the hammer head is in
the same vertical plane as that part of the face of the pulley G from which the belt
begins to separate when the hammer begins to fall.
The bearings g of the pulley shaft are fixed to the frame K those of the shaft h
are movable to allow the slight motion of separation above mentioned for the release
of the strap when the hammer head is desired to fall. The bearings g of the shaft h
are formed in a swinging support M which is pivoted to the frame K at m. The
centre of the pivot m is placed considerably nearer the vertical plane through the

page_text: centre of the shaft h than is the centre of the shaft which causes the frame M
always to hang in a position inclined to the vertical plane referred to. This is an
important principle of the construction. It will be seen that through this feature the
pulley Gis pendulous and tends to normally gravitate against the pulley G¹ and that
the weight of the hammer head acting through the strap or belt hanging from said
pendulous pulley presses the pulley G constantly toward the pulley when the
hammer head is being drawn up and this action alone suffices to firmly grip or clamp
the belt without any other mechanism than that described so that the force of the
grip is thus determined solely by the weight of the hammer itself thus greatly
simplifying the construction and securing a powerful pressure upon the belt difficult
to attain by other means. This mechanism also permits the employment of other
mechanism described below of a very simple and positively acting character for
releasing the flexible connection at the proper time for dropping the hammer head
and from any desired height according to the adjustment of a certain tappet R
hereinafter described which mechanism entirely obviates the above mentioned danger
of tearing the strap or belts, or appreciably retarding the fall.
From the lower part of the support M which carries the bearings g for the pulley G
extends backward toward the pulley G¹ a projection N preferably at or nearly at right
angles with the main portion of said support.
The extremities of the projection N has formed in it a notch n the use of which will
be hereinafter explained.
To the lower part of the frame K is pivoted at p an escapement O. This escape-
ment preferably has the form shown and it is pivoted at or about its middle part to
the frame K. It has formed upon or attached to it an upwardly extending flat-
ended projection g and at one end a hook or tooth q' the other end is pivoted to a
link Q which descends from the escapement and is also pivoted below to tappets R R¹
which in their turn are pivoted at to one of the upwardly extending hammer head
guides B.
To the escapement 0 is concentrically pivoted a pawl P' which when the machine
is in action alternately engages and disengages the projection N in the notch n. The
lower face of said notch serves as a support for the pawl and the upwardly extending
face of the notch acts as an abutment against which the flat end of the pawl presses to
hold the support M in the position shown in Figures 1 and 3 which is its position
either at the time the hammer head is at rest as shown in Figure 1 or preparatory to
freeing the belt from the pressure of the pulleys for permitting the fall of the hammer
head.
Projecting from the side of the escapement O is a lateral projections which is
situated between the central pivot of the escapement and the link Q and which
when the end of the escapement pivoted to Q is forced upward lifts the pawl out of
its engagement with the notch n in the projection N.
Pivoted to the shaft of the pulley G is a wedging separator or cam S which when
free turns upon said shaft by the action of friction only. This is an important part of
the mechanism its action being to press apart at proper times the pulleys G and G¹ in
order to release the belt or strap D and permit the fall of the hammer. Its construction
is as follows. It consists of a flat body with a central hub bored to fit with sufficient
accuracy the shaft h¹ and at diametrically opposite parts of said plate are wedges t t
projecting laterally in such manner as to overlie the perimeter of the pulleys G as
shown. Also from that side of said plate which faces toward the driving pulley I are
laterally projecting stops T T' said stops being also placed in diametrically opposite
positions the preferable relative positions of said stops with reference to each other
and the wedges being that shown in Figures 1, 2, and 3.
The operation is as follows, starting with the hammer head in the position of rest
and supported in that position as shown in Figure 1.
The hammer is started by the disengagement of the pawl F. The pulleys G and G¹
are held apart by the action of the pawl P against the projection N of the support M
and hence the belt is freed from the gripping action of the pulleys. The hammer
then freely falls. On reaching the tappet R it forces the inner extremity of said

page_text: tappet downward and raises the link Q: This forces the projections upward against
the pawl P and disengaging said pawl from the projection N allows the support M
to swing downwardly on its pivot m thus carrying the pulley G toward the pulley G¹
till the belt is pressed between said pulleys. The action of the pulleys then tightens
the belt against the resistance of the weight of the hammer and the tension thus
created draws the pulley G downward and toward the pulley G₁ with the force due
to said weight thus effectively and positively clamping said belt between said pulleys a
simple and certain method of securing this action which so far as I am aware is
entirely novel in drop hammers. .
The hammer being lifted in the manner described in its ascent it strikes against
the inner end of the tappet R. This depresses the outer end of said tappet and
forces downward the link Q. This rocks the escapement correspondingly and releases
the pawl P from engagement of the projection 's allowing the pawl to drop freely
and engage the projection N by the notch n as soon as the parts are brought into
position for such engagement.
Now during the rising of the hammer-head the wedging separator $ turns with
the shaft and pulley G' by the action of friction till the stop T abuts against
the upwardly projecting part 9 of the escapement O and there rests bringing the
wedge of the separator S into the position shown in Figure 2; and when the
hammer head reaches and raises the inner end of the tappet R to depress the link Q
the movement of the escapement O pivoted to said link causes the projection q to
disengage the stop T on the separator. The wedge t then enters between the
pulleys &G' and between the belt D and the pulley G and rotating concentrically
with and being drawn into the bite of the pulley thus forces or wedges the pulleys
apart to the position shown in Figure 3, the pawl then drops into the notch n on the
support M and thus the pulleys are held asunder during the drop of the hammer.
The wedge t then passes between the pulleys until the stop T engages the book or
tooth q on the escapement S as seen in Figure 1. This prevents further rotation of
the wedging separator until the hammer head reaches and actuates the tappet R¹
which raising the link Q again rocks the escapement into the position shown in
Figure 2 when the opposite end of the wedging separator repeats the action described
the opposite ends of the separator thus alternately acting to separate the pulleys and
release the belt.
If desired to relieve the belt from dragging over the perimeter of the pulley G
when the hammer falls any of the devices heretofore employed for that purpose
especially the one described in the Patent above referred to as granted to my
correspondent, may be employed.
It is evident that changes in proportion and arrangement of parts as well as in their
form may be made without substantially affecting the principle and operation of
this improvement which attains a combination of efficiency and simplicity that leaves
little to be desired.
It will be readily seen that the invention is not limited to any special number of
projections or stops T on the revolving separator S as they may be from one to
many two, four, or six being, however preferable. The shape of the projections t t¹
is preferably wedging but this is not essential as a projection of any form will act as a
.wedge between the pulleys. I do not however limit myself to any particular form of
wedging or separating device to separate the pulleys provided the hammer is so
hung from the pulleys that its weight alone acts to force them together and determines
the grasp of the pulleys on the belt in lifting the hammer as this is broadly new with
the present invention.
Having now particularly described and ascertained the nature of the said invention
as communicated to me by my foreign correspondent and in what manner the same is
to be performed I declare that what I claim is :-
1. In a drop hammer the combination with the hammer head of two separable
friction pulleys to which power is applied and a flexible strap or band connected with
the hammer head passing over one of said pulleys and between the two, the said

page_text: pulleys being so arranged and the hammer and strap so hung therefrom that the
grasp of the pulleys on the belt is determined solely by the weight of the hammer
head acting to force the pulleys together with suitable means for separating the
pulleys to release the belt and allow the hammer to fall substantially as herein
set forth.
2. In a drop press the combination with two separable friction pulleys a flexible
strap or connection passing between both pulleys over one of them and hanging
therefrom with a hammer head hung to the pendant end of the strap in such manner
that its weight tends to force the pulleys together to grip the strap and a movable
separator arranged to effect the alternate separation and approach of the pulleys
tappets, or projections arranged in the path of the hammer at the ends of the stroke
and operative connections between said tappets and separator substantially as shown
and described.
3. The combination in a drop hammer with a fixed driving pulley of a pendulous
or movable driven pulley tending to gravitate freely against the fixed pulley a flexible
connection or band passing between said pulleys and over the pendulous pulley and
hanging pendant therefrom and a hammer head attached to said pendant strap with
a device for separating the pendulous pulley from the fixed pulley at intervals in
accordance with the strokes of the hammer head substantially as herein set forth..
4. The combination in a drop press of the fixed pulley G₁ and movable driving
pulley G with the pivoted pendulous frame M in which the same is hung, flexible
connection D passing between said pulleys and over the pulley G and hammer C
hung to said connection with a supporting or separating device to normally hold
the pendulous pulley away from the fixed pulley and alternately allow the same to
gravitate against said fixed pulley by the weight of the hammer head substantially
as shown and described.
5. The combination with a drop hammer head two separable friction pulleys a
flexible connection attached to said head and engaged by said pulleys and arranged
to apply the weight of the hammer head itself to the production of the required
pressure upon said connection by said pulleys of a wedging separator arranged to
pass between and separate said pulleys and mechanism for holding the pulleys apart
when so separated until the hammer head has effected its blow substantially as and
for the purposes described.
6. In a drop press or hammer the combination with the hammer head and a belt
or band whereby the same is lifted of two separable friction pulleys to which the
driving force is imparted and between which the belt is gripped and drawn to raise
the hammer head with a revolving separator or wedge arranged to enter the bite of the
pulleys and thus revolve with the same and separate the pulleys by the action of
the rotating force and thereby free the belt and allow the hammer to fall with
escapement or detent mechanism controlling the arrest and release of the separator
coincident with the motions of the hammer substantially as herein set forth.
7. The combination of two separable friction pulley's a drop hammer head, a belt
or strap attached to said head and engaged with said pulleys in such manner that the
weight of the hammer head itself forces the pulleys together when the hammer head
is lifted and a wedging separator pivoted to the shaft of the fixed pulley and arranged
to pass between said pulleys at the proper time for forcing said pulleys apart
releasing the belt or strap from pressure and permitting the haminer to drop
substantially as and for the purpose set forth.
8. The combination of a friction pulley having fixed bearings a movable pulley
a swinging support for such movable pulley a drop hammer head a strap belt or
band engaged with said pulleys and attached to said head or drop in such manner
that the weight of the head or drop presses said swinging frame radially toward
said movable pulley for clamping said strap belt or band while lifting said head or
drop and a wedging separator pivoted to the shaft of the fixed pulley and arranged
to pass between and separate said pulleys at the proper time for releasing the belt
and permitting the hammer head to fall substantially as and for the purposes
specified.

page_text: 9. In a drop press or hammer the combination with the fixed driving pulley G¹
movable driven pulley G pendulous frame M strap D hammer C and gearing H H¹
and suitable means for causing the approach and separation of said geared pulleys
substantially as shown and described.
10. In a drop hammer the lifting mechanism of which consists in two friction
pulleys one of which has fixed and the other movable bearings and a strap belt or
band clamped between said pulleys and attached to the hammer head or drop the
separator herein described which consists of a body S pivoted to the shaft of the
pulley having fixed bearings, and having formed on it wedges and t¹ extending
laterally from said body over the perimeter of the pulley having said fixed bearings
substantially as and for the purposes set forth.
11. In a drop hammer the combination of a hammer head or drop C a pulley G¹
having fixed bearings a swinging support M having the notched projection Na
pulley G having bearings in said swinging frame a strap belt or band D attached
to the hammer head passing over the pulley G and between the pulleys G and G'a
wedging separator S pivoted to the shaft of the pulley G₁ and having formed
thereon laterally extending wedges t t and stops T T an escapement O pivoted to
the supporting frame of said fixed pulley and provided with an upwardly extending
projection and hook or tooth q' a pawl P pivoted to said escapement or support
for alternately engaging and disengaging said projection N tappets or tappet
levers R R pivoted to guide B and link pivoted to and connecting the escapement O
with said tappets or tappet levers substantially as and for the purpose specified.
Dated this 4th day of October 1887.