Improvements in Rasp Cutting Machines.
Year: 1897

page_text: Date of Application, 4th Sept., 1897-Accepted, 16th Oct., 1897
COMPLETE SPECIFICATION.
Improvements in Rasp Cutting Machines.
I, JAMES ALFRED MCHARDY of Providence, in the County of Providence and
State of Rhode Island, United States of America, Machinist, 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:-
The present invention relates to rasp cutting machines, and has for its object
the production of a machine of the above class which shall be simple in construction,
and which will run at a higher rate of speed than has hitherto been practicable,
and to this end the invention consists of the features and combinations hereinafter
described and claimed.
The machine illustrated in the drawings which embodies the present improve-
ments in their preferred form comprises generally, a blank supporting carriage
which is intermittently fed forward after the completion of each row of rasp teeth,
and a head which is oscillated about a fixed axis and carries a cutter rigidly secured
thereon. The rear face of the cutter is so formed that it lies in or within the arc
described by the point of the cutter, and the cutter is forced into the blank in
an arc, the rear face sliding along the bottom of the recess formed by its point,
or just clearing said recess, so that there is no pressure on the rear face of the
cutter. It is preferred to force the tool into the stock by means of a cam or
eccentric rather than by a blow, as in the former case the cutting tool enters the
blank gradually and at a slower speed so that the machine can be run at a higher
speed without heating the tool and blank. The cutting tool is mounted in a
carriage which slides on the oscillating head and is moved transversely of the
blank after the cutting of each tooth, by suitable means. The machine is also pro-
vided with means for regulating the transverse movement of the carriage while
the machine is in motion thereby adapting the machine for cutting tapered rasp
blanks. The detail construction of the machine will be understood by reference
to the following description taken in connection with the accompanying drawings
in which
Fig. 1 is a plan view of the machine.
Fig. 2 is a front elevation.
Fig. 3 is an elevation of the left end of the machine.
Fig. 4 is an elevation of the right end of the machine.
Fig. 5 is a vertical section through the blank supporting carriage partly in
elevation.
Fig. 6 is a vertical section through the shaft 31.
Fig. 7 is a detail view of the cam for feeding the tool carriage.
Figs. 8 and 9 are details of the cutter head and operating and adjusting means.
Figs. 10. 11. and 12 are details of parts to be described.

page_text: free and connected to a weight not shown by a link 10. The carriage 2 may be
fed forward after the completion of each row of teeth by any suitable means and
in the drawings is shown the preferred form of such means. Secured to the under
side of the carriage 2 is a rack 11 which is engaged by the pawl 12 pivoted to the
end of an arm or lever 13 pivoted to the frame at 14 and operated through a rod 15
pivoted thereto at 16. A spring 15 is secured to a shaft 15b and serves to hold
the pawl 12 in engagement with rack 11. The rod 15 is provided with a head
or flange 17 which fits within a cylinder 18 and is held against the end of said
cylinder by means of a spring 19 interposed between the head 17 and a plug 20
screwed into the end of said cylinder. The cylinder 18 is carried on the end of
a rod 21 which is pivoted at 23 to the rock arm. 22-secured to the rock shaft 23.
An arm 24 is also secured to the shaft 23 and is adjustably connected to a link 25
by means of a bolt 26 and slot 27, said link being also connected to a reciprocating
rod or yoke 28. The yoke 28 is guided in a bearing 29 in the frame and on a
block 30 which fits within a slot in said yoke and surrounds a shaft 31 mounted
in suitable bearings secured to the frame A. A bowl 32 on the yoke 28 runs
on a cam groove formed in a disc 33 secured to the shaft 31, said cam
groove being formed with the dwells 34, the swell 35 and the depression 36. The
shaft 31 is revolved intermittently through a ratchet wheel 37 secured thereto
which is engaged by a pawl 38 pivoted to a pawl carrying arm 39 loosely mounted
on shaft 31. Said cam 39 is reciprocated from an eccentric 39" mounted on the
main driving shaft 40 by means of the rod 41 pivoted to the end of said arm and
connected to the eccentric strap 42. The driving shaft 40 is driven continuously
by a band pulley 43 secured thereto and connected to any suitable source of power.
A notched locking disc 44 is secured to the shaft 31 and is engaged by a roll on
a spring arm 45 to lock said shaft in position after each forward movement, said
arm yielding and allowing the forward movement of said shaft under the action
of the pawl 38.
Any suitable means may be employed for limiting the feeding movement of the
blank carriage and releasing said carriage to allow the forward movement of
the same, but it is preferred to use the form of means shown which is as follows:
The carriage 2 is provided with the racks 46, 47 preferably secured on opposite
sides of the carriage and the teeth of which are staggered-that is, the teeth on
one rack are substantially the distance of half a tooth length in advance of the teeth
of the other rack. The racks 46 and 47 are engaged by teeth formed on the dogs
or slides 48 and 49 the teeth on said racks being in line or if desired, the rack
teeth may be in line and the teeth on the slides staggered. In either case, however,
when one dog or slide is in engagement with the teeth of its rack the other dog
or slide will rest on its rack half way between the teeth. The slides 48, 49 are
arranged in suitable ways on opposite sides of the carriage 2 and are operated at
the proper times by arms or tappets 50, 51 secured to the rock shaft 23 and engaging
the ends of said slides. The arms 50 and 51 extend from shaft 23 upon opposite
sides thereof so that when the shaft 23 is rocked in one direction one of said slides
will be operated and when said shaft is rocked in the opposite direction the other
of said slides will be operated.
The shaft 15b extends outside the frame and carries at its outer end an arm 52
which engages a pin 53 extending from the slide 48 and the other end of said shaft
carries an arm 54 which engages a similar pin 55 extending from slide 49. The
outer end of shaft 15b also carries a handle 55° by which said shaft may be turned
to lift the slides 48, 49 out of engagement with the racks 46, 47, the same movement
of the shaft also throwing the spring 15° into such a position that the pawl 12
will drop out of engagement with the rack 11 so that the carriage may be returned
to its initial position. A lever 56 is pivoted at 57 to an arm pivoted to the frame
and is connected to the carriage by means of the rod 58 and serves as a means for
returning the carriage to its initial position, after the completion of a rasp.
The tool or cutter 59 is rigidly clamped in the tool carriage 60 by any suitable
means, but preferably by the means hereinafter described, and the tool carriage is

page_text: rigidly supported on ways 61 formed on the head 62. Said head is loosely mounted
on a stud 63 secured in the frame A and an outer bearing B and may be oscillated
to force the cutter 59 into the blank to lift up the metal and form a tooth by any
suitable means. In order that the cutter 59 may enter the blank smoothly and
without any undue strain upon the cutter, and may bend or lift up the stock to
form a proper tooth, the rear face of said cutter is so formed that it lies in or
within an arc described about the axis of stud 63 as a center, that is to say in the
arc described by the point of the cutter. In practice the rear face of the cutter
will usually be ground so that there is a clearance between said face and the recess
formed in the rasp blank as the cutter enters the blank and said face will lie
within the arc described by the point of the cutter. The shape of the cutter
point will depend upon the shape of the tooth to be cut, but it is preferred to form
said point substantially V-shaped, and to so form the front face that it will be
substantially at right angles to the surface of the blank when the cutter is in its
forward position. The means shown and which it is preferred to use for oscillating
the head 62 to force the cutter into the blank consists of a cam 64 secured to the
driving shaft 40 and engaging a hardened steel plate 70 on an arm 65 secured to
said head. A rubber washer 71 may be interposed between the plate 70 and arm 65
if desired. A rod 66 pivoted to arm 65 has secured thereto a sleeve 67 which fits
within a cylinder 68 pivoted to the frame. A spring 69 surrounds said rod and
bears against the sleeve 67 and a plug 69ª screwed into the cylinder 68, and holds
the arm 65 against the cam 64.
In order to adjust the depth to which the cutter shall enter the blank, and also
to lift the cutter if desired so that it will not act on the blank, the arm 65 is ad-
justably secured to the head 62 and preferably by the means shown. As shown,
the arm 65 is pivoted at 72 in a recess formed in the head 62 and is provided
with a slot 73 in which a sliding block 74 is fitted. The block 74 is mounted on
an eccentric 75 formed on a stud 76 pivoted in the head 62 and having an arm 77
secured to its outer end. The arm 66 is provided with a rack 78 which is engaged
by a spring catch 79 on arm 77. By shifting the arm 77, the eccentric 75 will act
to lift the cutting tool away from the blank and thus decrease the depth of the cut
and by shifting the arm far enough the cutter will be lifted so that it will not act
on the blank.
After the cutting of each tooth it is necessary that the relative position of the
cutter and blank should be changed in order that the cutter may enter the blank
at a different point on the next reciprocation of said cutter and this is preferably
accomplished by moving the carriage on the head 62 although it is obvious that
the same result could be accomplished by moving the blank carriage laterally.
The preferred means for moving the tool carriage is as follows; The carriage is
provided with a lug, or projecting plate 80 in which is formed a curved slot 80°.
A sliding bar 81 is connected to the carriage 60 by means of a stud 82 which is
turned down and passes loosely through the slot 80, and is provided with the
washer 83 and nut 84 on its outer end. It is advisable that the rasp teeth be so
formed that they shall not be in line with each other longitudinally of the blank
and the stud 82 is therefore preferably adjustably secured to the bar 81 so that the
relative positions of the cutter and blank may be changed at will. In the form
shown, the stud 82 slides in the bar 81 and is adjusted and held in its adjusted
position by the handle 85 pivoted in said bar and connected to said stud by the
curved arm 86 which passes through a slot in the bar 81 and engages said stud.
The bar 81 is moved backward and forward step by step by the heart shaped cam 86
acting through the following connections. A slide or yoke 87 carries two bowls 88
which engage cam 86 on opposite sides and said slide is connected to one arm 89
of a bell crank lever 89 by means of the link 90. The other arm 91 of the bell
crank lever is connected with the bar 81 by a link 92. The cam 86 is moved a step
forward at each revolution of the driving shaft 40 by means of a pawl 93 pivoted
on the arm 39 and engaging a ratchet wheel 94 secured to the sleeve 95 on which
the cam 86 is also secured said sleeve being loosely mounted on the shaft 31. A

page_text: locking wheel 96 is also secured to sleeve 95 and is engaged by a roll on a spring
arm 97 to lock the cam 86 and therefore the tool carriage in position after each
feeding movement.
In order that the cutting tool may be accurately adjusted transversely with
relation to the blank, means are provided for adjusting the length of the con-
nections between the cam 86 and the carriage 60, and to adapt the machine for
cutting different width rasps, means are provided for regulating the transverse
feed of the carriage 60. In cutting tapered rasp-blanks it is necessary that the
distance the carriage 60 is moved after the cutting of each tooth should be varied
as the width of the blank varies, and it is, therefore, preferred to so construct the
means for regulating the transverse feed of the carriage that said means may be
operated without stopping the machine. The preferred form of the adjusting and
regulating means above referred to are illustrated in the drawings and are as
follows:
The link 92 is provided with a slot at its rear end in which slides a block 98 which
is adjusted by means of the screw rod 99 loosely pivoted in the link 92 and held
in position by the collars 100 and provided with a hand wheel 101 at its outer end.
A stud 102 projects from the upper side of the block 98 and carries a washer 103
which is held in place against the upper surface of link 92 by a nut 104. A
second stud 109 projects from the under side of block 98 and passes loosely through:
a block 105 mounted to slide in a slot 106 formed in the arm 91. A washer 107
is interposed between the under face of link 92 and the upper face of arm 91 and
the parts are held in position by a nut 108 and washer 110 on the end of stud 109.
The block 105 is recessed on one end and receives the flanged end 110° of a rod 111
screw threaded in the end of arm 91 and provided with a hand wheel 112. A
screw plug 113 surrounds the rod 111 and serves to hold the flanged end 110 in the
recess in block 105.
By turning the wheel 112 the pivoted connection between the link 92 and arm 91
is adjusted to or from the axis of the bell crank lever 89°, and the feed of the
carriage 60 thus regulated. By turning the wheel 101, the position of the carriage
and the tool carried thereby may be accurately adjusted transversely of the blank.
If desired, the adjusting devices above described may be placed at the pivotal
connections between the arm 89 and link 90 instead of at the connection between
the arm 91 and link 92, or they may be placed at both points as shown and the
range of adjustment thereby increased.
The cutter may be clamped rigidly to the carriage 60 in any desired manner,
but it is preferred to use the means shown for clamping said cutter, which consists
of the wedge shaped slide 113° which is operated by a cam or eccentric 114 formed
on the stud 115 pivoted in the carriage 60. The stud 115 is rotated to move the
slide 113 by a handle 118 keyed thereto and held in place by a washer and nut 116.
The cutting tool is placed in the recess 117 in the carriage, the front wall of which
is formed by the slide 113" and is clamped firmly between the rear wall of said
recess and said slide by turning the handle 118 to draw said slide toward the
right in Fig. 9.
The operation of the machine is as follows:
The blank 1 is placed upon the carriage 2 in the proper position and the
carriage moved into proper relation to the cutter 59, the cutter being raised out
of operation by throwing handle 77 to the left. The machine is now started,
and the handle 77 thrown to the right to bring the cutter into position to make
the depth of cut desired. The head 62 is reciprocated by the cam 64 at each
revolution of the shaft 40 and the cutter 59, being rigidly secured to said head,
is forced gradually into and under the metal of the blank 1 thus bending or lifting
the metal to form a rasp tooth, the peculiar formation of the rear face of the tool
allowing said action without any tendency to bend the cutter forward, and the
pressure on the front of the cutter being in lines substantially parallel to the rear
face. Each revolution of the shaft 40 also moves the cam 86 one step forward,
and thus feeds the carriage 60 laterally one step, the parts being so timed that the

page_text: forward movement of the cam takes place when the cutter 59 is clear of the blank 1.
The cam disc 33 is also moved one step forward at each revolution of the shaft 40,
the bowl 32 riding in the dwelis 34 and not effecting the yoke 28 while the
carriage 60 is being fed across the blank. Just after the carriage has been reversed
however, and while the cutter is still free from the blank, the disc 33 is moved
forward to carry the depression 36 past the bowl 32 thus forcing the yoke 28
downward and quickly returning it to its normal position. This movement of the
yoke 28 rocks the shaft 23 and through the arm 22 compresses or energizes the
spring 19 which tends to force the carriage 2 forward, through the pawl 12 and
rack 11, said carriage being held from movement by the teeth on slide 49 which
engage rack 47.
As the shaft 23 reaches the limit of its movement the arm 5.1
has lifted the slide 49 clear of the rack 47, and the carriage 2 is quickly fed forward
under the action of spring 19, said carriage being stopped by the engagement of the
slide 48 with rack 46. The bowl 32 now rides in the dwell 34 until the carriage 60
reaches the opposite side of the blank when the swell 35 is fed past the bowl thus
rocking shaft 23 in the opposite direction and energizing the spring 19 as before.
This movement of the shaft 23 lifts slide 48 thus releasing the carriage 2 so that
the spring 19 may act to feed said carriage forward, until the slide 49 engages the
teeth of rack 47 and stops said carriage. Thus the cutter is fed backward and
forward across the blank and the blank fed forward after the completion of eacn
row of teeth. In order that the teeth may not be in line with each other longitu-
dinally of the blank, the operator rocks the handle 85 to the right or left after the
cutting of every two or three rows of teeth, thus varying the relation of the blank
and cutter in the formation of different rows of teeth.
In cutting tapered blanks the operator gradually decreases the transverse feed
of the carriage 60 as the width of the blank decreases by turning the wheel 112,
and thus moving the block 105 nearer the axis of the bell crank lever 89ª.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:
1. In a rasp machine the combination with a support for the blank, of an
oscillating head mounted to oscillate about a fixed axis, a cutter rigidly mounted
on said head and having its rear face in or within the arc described by its point,
and means for oscillating said head to force said cutter into said blank to lift the
metal and form a tooth, substantially as described.
2. In a rasp machine the combination with a support for the blank, of an
oscillating head mounted to oscillate about a fixed axis, a cutter rigidly mounted
on said head and having its rear face in or within the arc described by its point
means for oscillating said head to force said cutter into said blank to lift the metal
and form a tooth, and means for regulating the depth to which the cutter shall
enter the blank, substantially as described.
3. In a rasp machine the combination with a support for the blank, of an
oscillating head mounted to oscillate about a fixed axis, a cutter rigidly mounted
on said head and having its rear face in or within the arc described by its point,
means for oscillating said head to force said cutter into said blank to lift up the
metal and form a tooth, and means for intermittently changing the relative posi-
tions of the cutter and blank, substantially as described.
4. In a rasp machine the combination with a support for the blank, of an
oscillating head mounted to oscillate about a fixed axis, a cutter rigidly mounted
on said head and having its rear face in or within the arc described by its point,
an arm secured to said head, a cam for rocking said arm, whereby said cutter is
forced into said blank and the metal lifted to form a tooth, substantially as
described.
5. In a resp machine the combination with a support for the blank, of an
oscillating head mounted to oscillate about a fixed axis, a tool carriage mounted
on said head, a cutter rigidly secured in said carriage and having its rear face

page_text: in or within the arc described by its point, means for oscillating said head to force
said cutter into the blank to lift the metal and form a tooth, and means for inter-
mittently moving said carriage on said head, substantially as described.
6. In a rasp machine the combination of an oscillating head, means for securing
a cutter to said head, an arm adjustably secured to said head, means for adjusting 5
said arm without stopping the machine, substantially as described.
7 In a rasp machine the combination of an oscillating head, means for securing
a cutter to said head, an arm pivoted to said head, and an adjustable connection
between said arm and head, substantially as described.
8. In a rasp machine the combination of an oscillating head, an arm pivoted 1
to said head, a stud pivoted in said head, a cam on said stud engaging said arm,
and means for adjusting said stud, substantially as described.
9. In a rasp machine the combination of a reciprocating head, a tool carriage
mounted on said head, means for feeding said carriage on said head, and means
for regulating the action of said feeding means without stopping the machine, 1
substantially as described.
10. In a rasp machine the combination of a reciprocating head, a tool carriage
on said head, a sliding bar, an adjustable connection between said bar and head,
and means for intermittently moving said bar, substantially as described.
11. In a rasp machine the combination of a reciprocating head, a tool carriage
on said head, a slot in said carriage, a sliding bar, a stud prejecting through said
slot and adjustably connected to said bar, substantially as described.
12. In a rasp machine the combination of a reciprocating head, a tool carriage
on said head, a sliding bar, a stud connected to said carriage and mounted in said
bar and a handle for regulating the position of said stud, substantially as described.
13. In a rasp machine the combination of a reciprocating head, a tool carriage
mounted thereon, a cam for moving said carriage on said head, connections
between said cam and carriage, means for regulating the action of said cam, and
means for adjusting the length of said connections, substantially as described.
14. In a rasp machine the combination with a reciprocating head, a tool
carriage mounted on said head, a lever, connections between said lever and said
carriage, means for adjusting said connections radially and transversely of said
lever, and means for oscillating said lever, substantially as described.
15. The combination of an arm, a block adjustably mounted on said arm
and provided with a stud, a second block pivoted on said stud, and a movable
part on which said second block is adjustably mounted, substantially as described.
16. The combination with a carriage, of means for feeding said carriage com-
prising a spring,,means independent of the carriage for energizing said spring,
and means for restraining and releasing said spring, substantially as described.
17. The combination with a carriage, of means for feeding said carriage com-
prising a spring, means independent of the carriage for energizing said spring,
a dog for restraining said spring, and means for releasing the dog, substantially
as described.
18. The combination with a carriage, of means for feeding said carriage forward
comprising a spring,. means independent of the carriage for energizing said spring
and means for,holding said carriage against the action of said spring and releasing
said carriage, substantially as described.
19. The combination with a carriage, of a rack secured to said carriage, a
pawl engaging said rack, means for reciprocating said pawl comprising a spring,
means for energizing said spring, and means for holding and releasing said
carriage, substantially as described.
20. The combination with a carriage, of a rack secured thereto, a pawl engaging
said rack, a rock shaft, a spring connection between said shaft and pawl, means
for holding said carriage against the action of said pawl and spring, and means
for releasing said carriage by the rocking of said shaft, substantially as described.
21. The combination with a carriage, of a spring for feeding said carriage
forward, means independent of the carriage for energizing said spring, a dog

page_text: for holding said carriage against the action of the spring, and means for releasing
said dog, substantially as described.
22. The combination with a carriage, of means for moving it in one direction,
racks at the sides thereof, dogs for engaging said racks, and cams bearing directly
upon the pawls for throwing the same alternately out of engagement with the
racks, substantially as described.
23. The combination with a carriage, two racks secured to said carriage, one
of said racks being a half tooth length in advance of the other, two slides provided
with teeth arranged to engage scid racks, means for alternately operating said
slides, and means for feeding the carriage forward, substantially as described.
24. The combination with a carriage, of means for feeding said carriage forward,
means for stopping and releasing said carriage, and mechanism for throwing said
feeding and stopping and releasing means out of operation, substantially as
described.
25. In a rasp machine the combination with a tool carriage provided with an
open sided recess for the reception of the tool, of a slide provided with an inclined
surface for clamping the tool in said recess, and means for operating the slide,
substantially as described.
26. In a rasp machine the combination with a tool carriage provided with an
open sided recess for the reception of the tool, of a slide provided with an inclined
surface for clamping the tool in said recess, and a cam for operating said slide,
substantially as described.
27. In a rasp machine the combination with a tool carriage provided with an
open sided recess for the reception of the tool, a wedge shaped slide forming one
of the walls of said recess, and means for operating said slide, substantially as
described.
28. In a rasp machine the combination with a support for the blank, of a head
mounted to oscillate about a fixed axis, a cutter rigidly mounted on said head and
having its point adjacent a vertical line passing through the axis of the head,
and means for oscillating said head whereby the cutter is carried both downward
and with an inward sweep, substantially as described.
100
JAMES ALFRED MCHARDY,
Haseltine, Lake & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.