Improvements in Molding Apparatus.
Year: 1895

page_text: Date of Application, 29th Jan., 1895-Accepted, 2nd Mar., 1895
COMPLETE SPECIFICATION (AMENDED).
Improvements in Molding Apparatus.
I, HARRIS TABOR, of 21, Elm Street, in the City of Elizabeth, in the County of
Union, and State of New Jersey, United States of America, Manufacturer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following state-
ment-
61
This invention relates to improvements in apparatus for producing nolds in which
metal-castings are to be made, and said improvements consist in providing the
apparatus with means for slightly agitating the patterns with relation to the sand in
the flasks, in order to free the patterns from any clinging particles of sand, when the
patterns are to be withdrawn from the molds, thereby doing away with the necessity
of a stripping-plate"; in mounting the pattern-plate upon a yielding support, in
order that such agitation may be the more effective, and the molds be left in better
condition when the patterns are withdrawn; in supporting the sprue-plug in the sand
so, that the molds cannot be damaged by any downward movement of said plug
when it is seized to be removed; and in certain other features of construction and
arrangement, all as hereinafter described and claimed.
In order to illustrate my improvements and their application, I have selected a
power molding-machine, the general construction and operation of which is similar
to that shown and described in Letters Patent of the United States granted to me
Mar. 17, 1891, and numbered 448,596, though said improvements may be applied
to machines differently constructed.
In the accompanying three sheets of drawings,
Figure 1 represents a front view of a power molding-machine to which the im-
provements are shown as applied, with the blocks on the ramming-head, the filled
flasks, the patterns, and portions of the parts in vertical section.
Figures 2 and 3 show vertical sections in two positions, of the three-way valve that
may be employed in the power inlet pipe.
Figure 4 represents a vertical section of the machine, on line X X of
Figs. 1 and 7.
Figure 5 shows, on a larger scale, a vertical section of a portion of the flasks, its
supporting-frame, and parts adjacent, illustrating the mounting of the pattern-plate
on yielding supports, and means for retaining the sprue-plug in position when the
patterns are withdrawn.
Figure 6 represents, on an enlarged scale, a vertical section of the cylinder or case
in which the power rapper, or agitator, is mounted to reciprocate, and shows the
valve-box governing the inlet of the medium for operating said rapper.
Figure 7 represents, a horizontal section, on line Y Y of Figs. 1 and 4, through

page_text: the flask and power-inlet pipe, and a top view of the automatic rapper and its con-
nections with the machine and with such pipe.
Figure 8 shows, on a larger scale, a vertical section of a portion of the flask,
pattern-supporting plate, and pattern, illustrating the effect (greatly exaggerated) on
the molded sand, of the operation of the rapper.
Figures 9 and 10 represent, on an enlarged scale, vertical, longitudinal sections of
the rapping-device with the reciprocating hammer in two positions.
Figure 11 shows, on an enlarged scale, in vertical section a check-valve which inay
be employed in the exhaust-pipe that connects with the main cylinder of the machine,
to govern the descent of the piston when near the end of its downward movement.
The specific construction of all the parts of the power molding-machine shown in
the drawings needs no description, as it forms, in general, no part of the present
invention. The machine, however, consists chiefly of a cylinder, 1, in which a
piston, 2, is mounted to be reciprocated vertically, the said piston carrying upon its
upper end a head or frame, 50, upon which normally rests a frame, 3, that supports the
flask or flasks, 4, and a pattern-holding plate or plates, 5, upon which the patterns, 6,
are secured. The pattern-plate is independent of the flask-supporting frame, and is
vertically movable with relation thereto, in order that the patterns may be withdrawn
from the sand after the molding operation has been completed. The machine is
furnished with a ramming-head, 7, to which are secured one or more blocks, 8,
according to the number of flasks to be rammed, and these blocks are adapted to
enter between the walls of the respective sand-boxes on the flasks in order to pack
the sand firmly upon and around the patterns. The piston, carrying the patterns and
flasks, is moved upwardly, to bring the sand in the flasks into engagement with the
blocks, S, by any suitable power, as steam, water, or air, which is introduced into the
cylinder, 1, through the pipe, 9, Fig. 1. This pipe is shown as being provided
with a three-way valve, 10, Figs. 2 and 3, which is operated by a lever, 11. When the
valve is in the position shown in Fig. 3, the steam (which is preferably used) passes
through the valve and enters the cylinders, at 12, Figs. 1 and 4, and forces the piston
to its highest point, thereby securing a proper ramming of the sand in the flask.
The lever, 11, is then operated to turn the valve, 10, into the position shown in
Fig. 2, thereby shutting off the entrance of steam, and opening the pipe, 9, into the
exhaust-pipe 13. The piston now descends by gravity, the patterns being withdrawn
from the sand by such descent; the head, 7, with its blocks, 8, is swang to one side,
as shown by dotted lines in Fig. 4, to enable the flasks to be conveniently reached,
and the flasks are removed. The arrangement of the parts by which the withdrawal
of the patterns from the sand is effected, is as follows: The rigidly-attached head or
frame, 50, on the upper end of the piston, carries cylinders or socket-pieces, 51, that
are occupied by guide-rods, 52, Figs. 1 and 4, depending from the flask-supporting
frame 3, so that the piston may move vertically independently of the frame, 3. On
each side of the machine, bars, 53, are pivoted at one end to the head, 50, and are
connected intermediate of their length to the flask-supporting frame, by links, 54,
which are pivoted at their lower ends to said bars, and at their upper ends
to hanger-arms, 55, depending from and attached to the flask-supporting
frame, 3. Arms, 56, are pivoted at their lower ends upon the cylinder-head,
and springs, 57, tend to swing them toward the central, vertical line of the
machine. When the piston is about to move upwardly, that the rainming-
operation may be performed, the parts are in the position shown in Fig. 4.
As the piston ascends, the free end of each bar, 53, moves up its adjacent arm, 56,
until it passes above the shoulder, 58, on the arm, when the arms are swung inward
by the springs, against the ends of the bars. When the piston begins to descend, the
bars, 53, are carried downward with it until their free ends rest upon said shoulders,
which now form fulcrums for the bars, and the descent of the flask-supporting frame
is thereby retarded, but not stopped. The pattern-plate continues to descend with
the piston, and as its rate of speed is greater than that of the frame, 3, or differential
with relation thereto, the patterns are gradually withdrawn from the molded sand.
After the flasks have been removed, the workman's foot is applied to a toe-piece, 59,

page_text: on the arm, 56, when the bars, 53, are released from the shoulders, 58, and the.
frame, 3, and bars, 53, fall by gravity to the positions shown in Fig. 4.
In a machine organized as above described, it has been found necessary to employ a
"stripping-plate," fitting closely around the patterns, in order that the sand at the
lower edges of the molds shall not break away or crumble off, when the patterns are
withdrawn; and the warming of the patterns has also been resorted to for this purpose.
The construction of such stripping-plates, and such warming, form a material expense
in the molding operation, and the stripping-plates can be conveniently applied only
to the exterior outline of the patterns. One object of my invention is to do away
with such plates, and the warming of the patterns:
This object. I accomplish by employing a rapping-device, which, by its operation,
very slightly agitates the patterns laterally with relation to the sand, and frees them
from any clinging particles of sand, so that the molds made by the patterns will be left
clean, and sharp at all the edges, when the patterns are withdrawn, thereby securing
a mold which is superior to one where a stripping-plate has been used, which plate
can only protect the edges of the mold that are in contact therewith.
The agitator or rapping-device, 14, shown in the drawings, consists of a movable.
block, or hammer, 15, which is mounted to be reciprocated by suitable means, in a
barrel or case, 16, Figs. 9 and 10. To secure the greatest durability, this hammer is
preferably provided at one end with a hardened steel plug, 17, and at the other end
with a similar plug, 18, which plugs receive the impact of the hammer against the two
screws, 19, 20, threaded into the respective ends of the case, 16. These screws are,
also, preferably hardened on their inner ends, and are made adjustable, so as
properly to control the amount of movement of the hammer under all, or varying
circumstances. A spring, 21, whose office is to return the hammer to its normal posi-
tion, shown in Fig. 9, bears at one end upon the hammer, and at the other upon a
screw-plug, 22, which plug enables the spring to be conveniently inserted, and
furnishes a means by which the same can be variably compressed. The case, 16, is
provided with two openings or ports, 23, 24, the former to admit the steam, or power
to drive the hammer toward the right hand, and into the position shown in Fig. 10,
and the latter to allow said steam to exhaust, as shown by the arrow on said figure,,
when the hammer has been desirably moved in such direction.
2
To govern the inlet of steam, the device is furnished with a suitable valve, 25,
Figs. 4 and 6, which is shown as adapted to be opened by a bent lever, 26, con-
nected to the outer end of the valve-stem and pivoted upon an arm, 27, projecting
from the valve-body. The valve is held closed, by a spring, 28, operating upon the
lever, or by any other suitable means. A flexible tube, 29, Figs. 1 and 7, is shown
as connecting the device with a pipe, 30, which enters the steam-supply pipe
above its valve, 10.
The agitating-device may be applied to the machine so as to operate upon the
flask, or upon its supporting frame, as will be readily understood, but I prefer to
have it operate upon the pattern-holding plate, or an attachment thereto. For con-
venience, the pattern-plate is secured to a frame, 47, Figs. 1, 4 and 5, which frame
virtually forms a part of the plate, and from this frame an arm, 48, is shown as
projecting laterally, Figs. 4, 5 and 7, to which the rapping-device is secured, so that
the movements of the hammer will impart a slightly tremulous motion, or agitation
to the pattern plate, and thereby free the patterns from sand and loosen them in
the molds, as shown in Fig. 8, where the clearance between the pattern and mold is
greatly exaggerated in order that the effect may be understood. As a matter of
fact, although this agitation secures the result desired, it does not perceptibly or
measurably enlarge the molds.
The rapping-device may be brought into operation when the ramming has been
completed, but I prefer to cause the device to act before such completion, in order
that it may perform the further office of causing the sand to settle into more
intimate contact with the patterns.
-
Various means may be employed for bringing the device into action, but the
means shown, consist of a vertical bar, 31, Fig. 4, projecting upwardly from the

page_text: head of the cylinder 1, and having an inclined portion, 32, which opens
the valve, 25, when the lever, 26, comes in contact therewith during the rising of
the piston, 2, and the parts which it supports. The length of time that the device
continues in action will depend upon the edge-contour of the bar, 31, which is
shown as straight, above the incline, 32, so that the rapping operation continues
while the ramming of the sand is being effected and until the patterns have been
partially withdrawn.
In order that the rapping may be the more effective for the purpose described, I
prefer to mount the pattern-plate upon a yielding support. Such a support is shown
in Figs. 1, 4 and 5, to consist of springs, 33, which are placed in sockets in the
head, 50, the springs bearing on their upper ends upon the frame, 47, to which the
pattern-plate is secured, as herein before described. This yielding support for
the pattern-plate performs a further useful office, which will now be explained.
In order to save time, it is desirable that the piston shall descend as speedily as
properly possible after the ramming has been effected; but, as a sudden downward
movement of the pattern-plate would be likely to disturb the molds made by the
patterns, the springs, 33, serve to hold the patterns in contact with the molds during
the initial portion of such downward movement of the piston, and until the springs
have fully expanded, when the pattern-plate will move with, and at the same speed
as the piston until the patterns have passed out of the sand, into the position.
indicated in Fig. 5, without in any way adding to the time of the piston's descent.
After the springs, 33, have expanded, the pattern-plate is caused to move downwardly
with the piston by the engagement of the head, 50, with nuts or stops, 60, located
on the lower ends of guide-pins, 61, which pins depend from the plate, 47, and pass
through holes in the head, 50, as shown in Fig. 1. Preferably the springs, 33, are
seated on adjusting screws, 34, Fig. 5, by which the force of the springs can be
desirably regulated.
As hereinbefore explained, the piston, 2, descends by gravity, when the steam has
been shut off and the exhaust-pipe opened; but as such descent, unless checked at
the latter end, would produce an undesirable jar, I prefer to employ a valve, in the
exhaust-pipe, which shall prevent such a result. Such a valve, 35, is shown in
Fig. 11, and its application to the exhaust-pipe is indicated in Fig. 7. When the
exhaust-pipe is opened, the pressure of the steam in the cylinder, 1, will raise the
valve-spindle, 36, from its seat, 37, against the pressure of the spring, 38 (which
spring-pressure can be regulated by the adjusting-screw, 39, according to the weight
of the piston and the time desired for its descent) and the steam will quickly pass
out of the cylinder until the pressure therein is reduced below that of the spring, 38,
when said spring will close the valve, and the remaining steam will be forced slowly
to escape through a leak-slot or slots, 40, in the valve-seat, or other small leak-
opening from the chamber, 41, unto the chamber, 42, thereby cushioning the piston,
and bringing it to rest without jar.
It is desirable that the sprue-plug, 43, Figs. 4 and 5, shall be removed before the
flask is taken from the machine, and as there is danger that said plug, if unsupported
at the bottom, may be forced downward, somewhat, into the molded sand when the
plug is grasped to be withdrawn, and the molds be thereby affected, I have provided
means for supporting such plug at the time it is applied and when the flask has
fully descended. These means are shown to consist of a post, 44, which is located
in axial, vertical alignment with the plug, passes loosely through a hole, 45, in the
pattern-plate, and rests upon a plate, 46, which is shown as supported upon the
hanger-arms, 55, that depend from the flask-frame, 3, Fig. 1. On the plate, 46, the
posts, 44, can be mounted so as to support the sprue-plugs wherever they may
be located in the sand.
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. In a molding apparatus, the combination of a flask-supporting frame; a pattern-

page_text: holding plate independent thereof; and a power device for agitating the plate or and
frame laterally relatively to the frame or plate eneh other; substantially as and for the
purposes specified.
2. In a molding-apparatus, the combination of a flask-supporting frame; a pattern-
holding plate independent thereof; and a yielding support for said plate, so arranged
that the plate can be vibrated laterally relatively to the frame, substantially as set
forth.
3. In a molding-apparatus, the combination of a flask-supporting frame; a pattern-
holding plate independent thereof; a yielding support for said plate, and a device for
agitating the plate and frame laterally relatively to each other, substantially as and
for the purposes specified.
4. In-a-molding apparatus, the combination-of-n-flask-supporting frame; a
pattern receiving-plate-independent thereof, provided with a projecting arm; and-a
device-mounted-on-said-arm;-for-agitating-the-plate;-substantially as-and-for-the
purposes-specified.
4. 5. In a molding apparatus, the combination of a ramming-head; a flask-
supporting frame; a pattern-receiving plate independent of said frame, said frame
and plate being movable to and from the head; means for moving the frame and
plate toward the head; a device for agitating the plate and frame laterally relatively
to each other; and means for automatically bringing said device into action during
such movement of said plate, substantially as set forth.
6. A-rapping device consisting of a case; a reciprocating hammer--mounted
therein; and a spring for returning-the-hammer to-normal-position, substantially as
get-forth.
5. In a vibrating rapping-device, the combination of a case a reciprocating
hammer mounted therein; adjustable stops for limiting the movements of the
hammer; and a spring for returning the hammer to normal position, substantially as
set forth.
6. 8. In a vibrating rapping-device, the combination of a case having inlet and
exhaust ports; a reciprocating hammer mounted in said case; adjustable stops for
limiting the movements of the hammer; and a spring for returning the hammer to
normal position, substantially as set forth.
7. In a molding-apparatus, the combination of a flask-supporting frame; a
pattern-receiving plate; and a support for the sprue-plug, which is independent of
said plate, substantially as set forth.
10. In a molding apparatus, the--combination of a piston; a flask supporting
frame, and a pattern-receiving-plate-mounted-on-said-piston-and-movable-with rela-
tion-to-each other; springs upon which said pattern-plate is supported--by-the
piston; and guides-and-stops for-defining the movement of said plate relatively to
the-piston, substantially as-set-forth.
11. In a power molding apparatus, the combination of-a-cylinder; a piston
mounted-therein; a flask supporting frame and a pattern-receiving plute-mounted
en-suid-piston independent-of-ench-other; a-yielding support for said plate; and
means-for-securing-a-differential, downward--movement of suid-frame-and plate,
substantially as-set-forth.
8. 12. In a power molding-apparatus, the combination of a cylinder; a piston
mounted therein; a flask-supporting frame and a pattern-receiving plate mounted on
said piston; a ramming-head; and a valve located in the exhaust passage from the
cylinder and having an adjustable spring for controlling the valve, and a leak-orifice
O for securing a cushioning of the piston, substantially as set forth.
Dated this 28th day of January love,
WALLACE FAIRWEATHER,
Chartered Patent Agent,
62, St. Vincent Street, Glasgow, Agent for the Applicant.