Improvements in Machines for Cutting Tapered Grooves or Slots in Wood, Metal, and the like.
Year: 1895

page_text: Date of Application, 27th Dec., 1895
Complete Specification Left, 11th Feb., 1896-Accepted, 21st Mar..
1896
PROVISIONAL SPECIFICATION.
Improvements in Machines for Cutting Tapered Grooves or Slots
in Wood, Metal, and the like.
We, WILLIAM LISTER, Joiner, of 9 East Moor Road, Pallion, and, JOHN
CARDWELL, Engineer, of Brooke Street Engine Works, Monkwearmouth, both in
Sunderland, in the County of Durham, do hereby. declare the nature of this
invention to be as follows:-
This invention relates to improvements in machines for cutting tapered grooves
or slots where such are required as for example in stair-trenching and in many
other instances.
To effect our purpose we propose to construct in the case of a stair-trenching
machine a double-armed machine both of which arms are capable of combined
vertical adjustment as well as of lateral or horizontal and separate adjustment
with regard to each other such adjustments of position being effected by screw
mechanism equivalent to a slide rest motion device.
The arms may be arranged at or about right angles to each other and one will
be capable of travelling or being worked as just foreshadowed along the other.
On one of the arms there will be mounted a bracket carrying a vertical or other
spindle adapted to rotate by pulley and belting or equivalently otherwise. The
bracket will be capable of being worked backwards and forwards on the arm by a
The bottom or
screw motion resembling the slide rest motion already alluded to.
lower part of this spindle will be split, up or grooved to take a knife which will be
pivoted or otherwise hung therein.. The form of the back or sides of the knife is
peculiar but substantially it, will be more or less inclined or cam-shaped or
undulating. A collar is intended to surround and work up and down on the spindle
opposite the knife and from the collar there will project inwardly certain studs or
arms which will work in the spindle or knife slot or slots and as the collar is lifted
or lowered as, hereinafter described the studs will act on the back or sides of the
knife to more or less alter its centre as required.
The collar will be flanged and its flange will work in an inclined or equivalent.
groove device formed in the arms of the machine so that as the bracket is traversed
along an arm the collar will be raised or lowered as the case may be by reason
of its flange following the inclination of the grooves in the arms and this vertical
movement of the collar is utilised by means of the studs or the equivalents thereof
to actuate alter or, control the exact position or centre or eccentricity of the
rotary knife which can thus be utilised to form tapered grooves or slots as herein-
above foreshadowed. :
To control the position of the belt driving the spindle during the changes of
motion of its bracket we suitably connect the bracket by a distance and regulating
rod to a pivoted tail-table having a slot therein and carrying a pivoted pulley-
bracket which can, thus reciprocate in the slot as well as maintain a direct lead
of belt between the pullies. The whole apparatus may be mounted on a suitable
pedestal adjustably connected to a bench or table so as to permit of the machine
being partially rotated or adjusted as required.
In the case of a stair-trenching machine such as has been above described the
bracket and knife working as described will first be traversed along one (say the
shorter) arm to form say the riser-trench: the arm and bracket and knife will then
17

page_text: be traversed (these operations being performed as above adumbrated and for
example manually) along the other arm to form the trod-trench and in such a
case the collar aforesaid after being operated by the inclined groove in one arm is
then operated by the inclined groove of the other arm to perform the necessary
function as above outlined.
The apparatus it will be understood though described more or less as specially
applied to a stair-trenching machine is applicable to all cases where tapered
slots or grooves are required to be cut in wood or metal by simply adapting the
knife to the circumstances of any required case.
Dated this 24th day of December 1895.
A. CRAWHALL CHAPMAN,
3 St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.
COMI LETE
SPECIFICATION,
Improvements in Machines for Cutting Tapered Grooves or Slots
in Wood, Metal, and the like.
We, WILLIAM LISTER, Joiner, of 9 East Moor Road, Pallion, and JOHN
CARDWELL, Engineer, of Brooke Street Engine Works, Monkwearmouth, both in
Sunderland, in the County of Durham, 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 improvements in machines for cutting tapered grooves
or slots in wood metal and the like or where such are required as for example in
stair-trenching and in many other instances.
To effect our purpose we propose to construct in the case of a stair-trenching
machine a double-armed machine both of which arms are capable of combined
vertical adjustment as well as of lateral or horizontal and separate adjustment
with regard to each other such adjustment of position being effected by screw
mechanism equivalent to a slide rest motion device.
"The arms may be arranged at or about right angles to each other and one will
be capable of travelling or being worked as just foreshadowed along the other.
On one of the arms there will be mounted a bracket carrying a vertical or other
spindle adapted to rotate by pulley and belting or equivalently otherwise. The
bracket will be capable of being worked backwards and forwards on the arm by
a screw motion resembling the slide rest motion already alluded to.
The bottom or lower part of this spindle will be split up or grooved to take a
knife which will be pivoted or otherwise hung therein. The form of the back or
sides of the knife is peculiar but substantially it will be more or less inclined or
cam-shaped or undulating. A collar is intended to surround and work up and down
on the spindle opposite the knife and from the collar there will project inwardly
certain studs or arms which will work in the spindle or knife slot or slots and as
the collar is lifted or lowered as hereinafter described the studs will act on the
back or sides of the knife to more or less alter its centre as required.
The collar will be flanged and its flange will work in an inclined or equivalent
groove device formed in the arms of the machine so that as the bracket is traversed
along an arm the collar will be raised or lowered as the case may be by reason of
its flange following the inclination of the grooves in the arms and this vertical
movement of the collar is utilised by means of the studs or the equivalents thereof
to actuate alter or control the exact position or centre or eccentricity of the rotary
knife which can thus be utilised to form tapered grooves or slots as hereinabove
foreshadowed.
To control the position of the belt driving the spindle during the changes of
motion of its bracket we suitably connect the bracket by a distance and regulating

page_text: rod to a pivoted tail-table having a slot therein and carrying a pivoted pulley-
bracket which can thus reciprocate in the slot as well as maintain a direct lead of
belt between the pulleys. The whole apparatus may be mounted on a suitable
pedestal adjustably connected to a bench or table so as to permit of the machine
being partially rotated or adjusted as required.
In the case of a stair trenching machine such as has been above described the
bracket and knife working as described will first be traversed along one (say the
shorter) arm to form say the riser-trench: the arm and bracket and knife will then
be traversed (these operations being performed as above adumbrated and for
example manually) along the other arm to form the trod-trench and in such a case
the collar aforesaid after being operated by the inclined groove in one arm is then
operated by the inclined groove of the other arm to perform the necessary function
as above outlined.
The apparatus it will be understood though described more or less as specially
applied to a stair-trenching machine is applicable to all cases where tapered slots
or grooves are required to be cut in wood metal or the like by simply adapting
the knife to the circumstances of any required case.
We will fully describe our invention with reference to the accompanying
drawings in which
Figure 1 shows a general plan view of a machine adapted to cut tapered grooves
or trenches in stringer beams such trenches afterwards being intended to be fitted
with the trods and risers of or forming the stairs.
Figure 2 is an elevational view looking at the machine from the point N.
Figures 3 and 4 the latter in section show two enlarged views at right angles
to each other of the arrangement of the knife collar studs and spindle hereinafter
alluded to.
Figure 5 is a cross-section of the tail-table.
Figure 6 is hereinafter explained and in the following description like marks of
reference designate like parts.
Referring to the drawings on the pedestal 1 is mounted as shown the double-
armed stair-trenching or grooving apparatus consisting of a long arm 2 corresponding
to the trod-trench and a short arm 3 corresponding to the riser-trench. The whole
of this double-armed structure is capable of slight vertical adjustment by the
screw 4 operating after the well-known manner of a slide rest device in an ordinary
lathe. The arm 3 is likewise capable of being worked backwards and forwards
along the arm 2 by a screw 5 and the bracket 6 on the arm 3 is likewise capable
of being worked backwards and forwards along the arm 3 by a screw 7, the several
motions effected by the screws 4, 5 and 7 on respectively the double-armed
apparatus as a whole with regard to the pedestal on the short arm with regard to
the long arm and on the bracket with regard to the short arm being precisely
analogous to the traversing screw motion of an ordinary lathe slide rest device.
The pedestal is capable of a slight horizontal radial motion on its table 8 by
simply adjusting the screw-studs 9" with regard to the slots 9 in the table as shown.
The tail-table 10 is pivoted to the pedestal at 11 and in a groove 12 thereof a
block 31 carrying a pivoted bracket 13 is adapted to slide backwards and forwards
to the required extent as hereinafter described. The tail-table is thus capable of
a slight radial motion round its centre at 11. The bracket 13 carries the pulleys 14
for conveying a belt to and from the pulley 16 mounted on the spindle 17 working
in and supported by the bracket 6. A connecting or distance rod 18 connects the
pivoted bracket 13 with the bracket 6 so as to maintain a constant distance between
the pulleys 14 and the pulley 16. Further we provide a slit 19 in the base of the
spindle 17 in which slit a peculiarly formed knife 20 is hung as at 21.
Adapted to act in conjunction with the cam-shaped or inclined backs or sides
of the knife are studs or projections 22 fitted in the collar 23 which again is
adapted to work up and down the spindle by means of its flange or extension 24
working in the inclined grooves 25 and 26 of respectively the arms 3 and 2 and
according to the shape or inclination of the back or edges of the knife 20 so may

page_text: the amount of its eccentricity and consequent taper in the trench groove or slot.
to be made be varied or modified as herein described.
Now supposing we wish to form in a stair-stringer beam tapered trenches of the
form shown in Figure 6 the bracket 6 will in the first instance have been traversed
along to the outer end of the short arm 3 and the short arm will have been traversed
along to the inner end (nearest the pedestal) of the longer arm 2. The wood
beam being in position the belting will be put in motion to drive pulley 16 and
rotate the spindle and knife. The attendant will then by a handle at 27 traverse
the bracket 6 and spindle and knife inwards towards the long arm 2 (thus grooving
the wood) and as this happens the collar 23 owing to the working of its flange 24
in the descending groove 25 will be lowered on the spindle and one of the studs 22
opposite the inclined back of the knife will in consequence push the knife slightly
and gradually over to the required extent thus varying the degree of eccentricity
of the knife and causing a tapered groove to be cut until the bracket and spindle
reach the inner end of the short arm when the flange of the collar will then gear
with the opposite or ascending groove 26 of or in the longer arm 2. The part S S
(Figure 6) will then have been cut. The handle at 28 will then be utilised to
traverse the short arm bracket spindle and knife firstly inwards towards S' and
then outwards along the long arm to S² (Figure 6) and in doing this the flange of
the collar working in the now ascending groove will be raised on the spindle which
will have the effect of causing one of the studs to again actuate the inclined back
of the knife in manner and for the purpose hereinabove already described and
when the bracket has travelled to or nearly to the outer end of the long arm
(sec dot and dash lines Figure 1) the necessary tapered grooves will have been
completed as shown in Figure 6.
The opposite sides of the knife 20 against which the studs 22 abut and work are
of course parallel with each other.
When the bracket reaches the inner end of the short arm and at the point when
the flange of the collar gears with the inclined groove in the long arm in order to
allow the collar to rise in the ascending groove a portion P of the metal of the
short arm is cut away as shown.
As the bracket 6 moves from the outer end of the short arm inwardly the rod 18
pushes the pulley bracket 13 away along the grooved path in the tail-table and
owing to the special arrangement shown and described the pulley bracket 13 is
always kept at a constant distance from the bracket 6 and the lead of the belt is
also always kept true in whatever position the bracket 6 may be with regard to
the bracket 13 and to the arms 2 and 3.
Figure 5 shows in sectional view how the bracket 13 is arranged on the tail-
table with friction rollers r to facilitate its easy travel along the slot 12 and the
pin 30 in the block 31 whereon it is pivoted.
In Figures 1 and 2 R is a rib of arm 2 and R' a rib of arm 3.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. For forming tapered grooves or slots in wood metal and the like the
combination with a spindle having a basal slit therein containing a hung knife the
spindle being capable of revolution and traversing motion along the arm or arms
of the machine of a collar adapted to ascend or descend on the spindle by means
of the gearing of its flange with an inclined groove in the arm or arms of the
machine and so to vary by means of studs or projections therein acting on the
inclined back of the aforesaid knife the position of the latter so as to enable a
tapered groove or slot to be cut the several parts being arranged combined or
adapted to operate substantially as and for the purposes herein set forth.
2. For forming tapered grooves in stringer beams for stair risers and trods the
combination with the arm 2 adjustably mounted on the pedestal 1 of the arm 3
capable of being traversed along the arm 2, the arm 3 being provided with a

page_text: bracket 6 capable of being traversed along itself and carrying a spindle 17 having
a slit 19 containing a hung or pivoted knife 20 the knife being capable of
automatic adjustment as to its centre or position, for the purpose of forming tapered
grooves by means of the collar 23 with its studs 22 and flange 24 gearing with the
grooves 25 and 26 in the arms of the machine, the spindle pulley 16 being driven
by belting from pulleys 14 mounted in a pivoted bracket 13 adapted to work in
a groove 12 of the tail-table 10 the pulleys 14 and 16 being kept at a constant
distance from each other by the rod 18 all these parts being arranged combined or
adapted for working substantially as herein set forth.
3. The general arrangement or combination of parts comprising an improved
machine for cutting tapered grooves or slots in wood metal and the like arranged
combined or adapted for use substantially as herein described and illustrated in
the accompanying drawings.
Dated this 10th day of February 1896
A. CRAWHALL CHAPMAN,
3 St. Nicholas Buildings, Newcastle-on-Tyne, Patent Agent.