IMPROVEMENTS IN DROP HAMMERS
Year: 1888

page_text: 1, FRANK MCDOWELL LEAVITT, of No. 17 Adams Street, Brooklyn, in the County
of Kings and State of New York, in the United States of America, Mechanical Engi-
neer, do hereby declare the nature of my invention for IMPROVEMENTS IN DROP
HAMMERS, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement :-
Prior to my invention, hammers of the class to which this invention relates have
been provided with flexible straps, or with upwardly extending wooden strips or
boards, which straps, strips or boards were clamped by revolving rollers when the
hammer body was raised, the pressure upon the strap, strip or board being thrown off
when the hammer dropped; but such constructions are open to many objections, in
that the straps, strips or boards were constantly wearing out, and hence the machines
frequently had to be stopped for repairs; and it also frequently happened that the
parts would give out, owing to inherent defects, and the operator's hands would be
injured by the premature falling of the hammer.
It is to overcome the above objections and at the same time to provide an improved
form of drop hammer, that I have designed the hammer forming the subject matter
of this specification, the invention consisting essentially of a pair of friction rollers,
that are mounted in a plane through which the body of the hammer travels when in
operation, the rollers being arranged in connection with a mechanism by which they
may be moved toward and from the side faces of the hammer body, all as will be
hereinafter more fully described and specifically pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
specification, in which similar figures of reference indicate corresponding parts in all
the views.
front elevation of my improved drop hammer.
Figure 1 is o

page_text: Figure 2 is a side view, parts being broken away and parts being shown in
section.
Figure is a sectional detail view taken on line - of Figure 1; and
Figure 4 is a sectional plan view taken on line y-y of Figure 3.
In the drawings I have represented the hammer body 10 as being rectangular in
cross section, the angles, however, being cut away to form guiding faces 2 which rest
against corresponding faces 3 that are formed upon uprights 11, at each side of the
entrances to vertical recesses 12, which enter the bodies of the uprights; but any
other proper form of haminer body, and any other proper form of guiding ways
could be employed without departing from the spirit of my invention.
The uprights 11 are secured to a base 13 and this base also serves as the support
for the lower die 14, which die is adjusted to the required position by means of set
screws 15. The upper die 16 is connected to the lower end of the hammer body,
and the heads of the set screws 17 by which the die is held in place pass within the
recesses 12 when the hammer is in operation.
At each side of the hammer body I journal a centrally divided, cylindrical
housing 18, of which the bearings 19 are mado integral with or rigidly connected
to the uprights 11. The sections a and 6 of these housings are connected by a
curved web or plate 5, which plates also serve as guards, as will be presently
explained.
Through the housings 18, I pass driving shafts 20 which carry pulleys 21, the
shafts however being so arranged that they will be eccentric to the axes of the
housings.
Upon the exposed portions of the driving shafts between the sections a and b of
the housings 18, beneath the guard plates 5 and just opposite the hammer body I
mount friction rollers 22, said rollers being concentric with their shafts.
From the construction described it will be seen that if, while the rollers 22 are
revolving in the direction of the arrows shown in Figure 2, and the housings 18 be
moved in corresponding directions, the rollers will be brought to bear against the
side faces of the hammer body, and that said body will be raised, as indicated in
Figure 3.
Many forms of mechanism might be employed to move the housings as above set
forth, but 1 consider the mechanism shown in the drawings one of the best for this
purpose. The mechanism referred to consists of a treadle 23, which, by means of a
rod 24 and links 25 is connected to two heads 26, the leads in turn being rigidly
connected to the housings 18 by dowels 6, or by other proper connecting attach-
ments. By this arrangement, when the outer end of the treadle is depressed the
rod 24 will be raised, and the housings turned so as to carry the shafts 20 and con-
sequently the rollers 22 toward the hammer body to a position such that the rollers
will bear against said body and carry it upward as they revolve, but when the
pressure upon the treadle is relaxed the rollers will fall away, and the hammer will
drop.
Having now particularly described and 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 :-
1. A haminer body mounted to be raised by the direct action of rollers upon the
hammer body.
2. The combination with a hammer body mounted to slide in ways, of revolable
rollers movably mounted at the sides of the hammer body, substantially as shown and
described.
3. The combination with a hammer body mounted to slide in ways, of rovolable
rollers mounted at each side of the hammer body and a means for throwing said
rollers toward said body, as and for the purpose stated.
4. The combination with a hammer body mounted to slide in ways, of revolable
rollers mounted in a plane through which the hammer body travels, and a means for
throwing the rollers toward the hammer body, as and for the purpose statod.

page_text: 5. The combination with a haminer body and its guides, of rollers, shafts upon
which the rollers are mounted, housings through which the shafts are passed eccen-
trically, and a means for turning the housings, as and for the purpose stated.
6. The combination with a hammer body and its guides, of rollers mounted upon
shafts at the sides of the banner body, housings through which the roller shafts are
passed eccentrically, a treadle, a rod connected thoreto, links connected to the rod,
and connections between the links and the housings, substantially as described.
Datel this 10th day of April 1888
HERBERT J. ALLISON,
Agent for the Applicant.