Improvements in Reciprocating Metal-cutting Machines.
Year: 1897

page_text: Date of Application, 6th Apr., 1897-Accepted, Sth May, 1897
COMPLETE SPECIFICATION.
Improvements in Reciprocating Metal-cutting Machines.
I, ALEXANDER GORDON, of Hamilton, Butler County, Ohio, United States of
America, Manufacturer, 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 pertains to improvements in reciprocating metal-cutting machines
of that general class exemplified by planing machines, slotting machines, shaping
machines, &c.
In machines of this class, especially in the larger sizes, there has been a modern
tendency toward increase in working speeds and in rate of feed. The prompt
reversal of reciprocating parts at high speed, and the production of extensive feed-
motions have been seriously limited or rendered difficult by the practice of deriving
the reversing and feeding-motions from the reciprocating part at or during the
reversal at a time when the operating power-mechanism was virtually disconnected
from the reciprocating part, the momentum of the reciprocating part being depended
upon to produce the desired effects. Again, great difficulty has been experienced
in securing a satisfactory relieving motion for the tool during the backing stroke,
and the numerous complicated devices which have been contrived for this purpose
have been so inefficient and troublesome that they are seldom employed notwith-
standing the recognised desirability of positively relieving the tool on the backing
stroke. In my improved system I provide for effecting the reversal of motion, or
the production of the feeding motion, or the relief of the tool, or all of these, by
means of a force extraneous to that employed in giving the reciprocating motion.
I employ a pneumatic engine whose sole duty it is to move certain parts pertaining
to the reversal or feeding or tool-relieving, and I impose upon the main recipro-
cating part of the machine only the trifling duty of moving the valve of this
pneumatic engine.
My invention readily lends itself to planing machines, shaping machines, slotting
machines, and the particular character of driving mechanism employed in the
machine, as well as the particular character of feeding mechanism, is immaterial.
For purposes of exemplification I show my invention in connection with a planing
machine of ordinary type having usual driving mechanism and usual feeding
mechanism. My invention will be readily understood from the following description
taken in connection with the accompanying drawings in which :-
Fig. 1, is a side elevation of a metal planing machine embodying my invention,
the pneumatic engine appearing in vertical section in the plane of line b of
Fig. 3:
Fig. 2, a side elevation of the pneumatic engine:
Fig. 3, a plan of the planer, portions appearing in horizontal section in the plane
of line a of Fig. 1:
Fig. 4, a side elevation of the clutch-arm, the clutch shaft appearing in vertical
transverse section in the plane of line c of Fig. 3: and
Fig. 5, a vertical section of the tool-relieving valve.
In the drawings:
:-
1, indicates the planer bed:
2. the planer table :

page_text: ՆԱՂԵԼ,
24, a rack gearing therewith and connected with piston rod 22:
25, the controlling valve of the pneumatic engine:
26, the valve arm :
27, an arm mounted at its base on a pivot carried by piston rod 22:
28, a link connecting the upper end of this arm with reversing tumbler 5:
29, a link connecting valve arm 26 with an intermediate portion of arm 27: and
30, the clutch rod, connecting clutch 16 with clutch arm 18.
The pneumatic engine is to be supplied with compressed air from any suitable
source of supply. With the parts in the position shown in Fig. 1 the planer is at
rest. If tumbler 5 be thrown to the left, by hand, valve 25 will obviously admit
air to the left of the piston and the piston will move to the right, throwing the
clutch into engagement with cutting pulley 14 and the planer table will proceed to
make its cutting stroke while the clutch is held in engagement by pressure on the
piston. When, at the termination of the cutting stroke, backing dog 7 rocks
tumbler 5 to the right, then valve 25 will be reversed and the piston will move
to the left and cause the clutch to lock the backing pulley 15 to the driving shaft
and cause the planer to make its backing stroke, and so on, the pneumatic engine
causing a reversal of the direction of driving motion each time its valve is reversed
under the influence of one of the dogs, the piston not only adjusting the clutch for the
proper direction of motion but holding the clutch into engagement. It is obvious
that the movement of the piston not only thus effects the reversal of motion of the
table but effects also the proper motion of the feed mechanism. And it will be
apparent that the shifting of the clutch, and the holding of the clutch into
engagement, and the operation of the feed, calls upon the planer table only for
such slight power as is necessary to move the valve of the pneumatic engine.
The power and promptness of the shifting and the feeding motions are thus
independent of the amount of energy stored in the reciprocating table.
In reversing the machine by hand, as by operating handle 6, only sufficient
power need be applied to operate the valve of the pneumatic engine, the engine
itself performing the real work of reversing the clutch and operating the feed.
When the planer table is in motion, in either direction, tumbler 5 is at one
or other of its extremities of motion. If, under these conditions, it be desired to

page_text: stop the planer, the tumbler need only be brought to the neutral position by means.
of handle 6. With the parts in the position shown in Fig. 1 this would put
valve 25 to neutral position and we must assume that the piston was at one
extremity of its stroke. Hence it would appear that putting the tumbler and
valve to neutral position would not necessarily move the piston to neutral position
and release both clutches. But when the piston is at one extremity of its stroke
and the tumbler is moved to neutral position the result is, not the placing of the
valve in neutral position, but the reversal of the valve, by reason of the operation
of arm 27, and the reversal of the valve causes the piston to start on its stroke
and when it reaches mid-stroke the motion of the lower end of arm 27 will have
put the valve to mid-position, leaving the parts all in neutral position and the
planer at rest.
35, the apron, all of these parts being constructed as usual :
36, the pivot bolt as usually employed in uniting the apron-box to the slide so-
as to permit the apron-box to be adjusted to angles, this pivot bolt in the present
instance, however, being bored to form a small air cylinder within it :
37, a piston working in this cylinder and having its piston-rod projecting
forwardly so as to engage the rear of the apron :
38, a three-way cock or valve :
39, the inlet to this valve, from the source of supply of compressed air:
40, exhaust pipe from this valve :
41, a conduit leading from the three-way valve to the cylinder formed within.
pivot-bolt 36 behind piston 37 and
42, a stud on lever 27 adapted, as piston-rod 22 reciprocates, to engage a lever
on the stem of the three-way valve and turn it to one or the other of its extreme
positions.
When the planer is at rest, and also when it is making its cutting stroke,
conduit 41 is in communication with the exhaust 40 and consequently there is no
air pressure behind piston 37 and that piston is inert and the apron is free to
occupy its normal position. When piston 21 moves to the right and causes the
planer to begin its backing stroke then pin 42 turns valve 38 so that the air
pressure is admitted behind piston 37, whereupon the piston moves forward and
lifts the apron and gives the proper relief to the cutting tool. When the planer
motion is reversed and the cutting stroke begins then valve 38 again opens the
exhaust and relieves the pressure at the rear of piston 37, allowing the aprou to
again fall. A spring may, if desired, be added to piston 37 to move it rearwardly
when the exhaust takes place so as to impose less duty upon the apron as the
apron falls to normal position preparatory to the cut.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :-
A reciprocating metal-cutting machine provided with a pneumatic engine
controlled by the movements of the machine and in turn controlling the reversing
device or the feeding device or the tool-clearing device, or all of said devices.
WILLS uay
ALLISON BROS.,
Agents for the Applicant.
ALLISON BROS.,
Agents for the Applicant.