An Improved Machine for Trimming the Tenons of Wooden Boxes.
Year: 1894

page_text: Date of Application, 1st M.y, 1894-Accepted, 2nd June, 1894
COMPLETE SPECIFICATION.
An Improved Machine for Trimming the Tenons of Wooden Boxes.
I, CHARLES CRISTADORO, of St. Paul, in the County of Ramsey, and State of
Minnesota, 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:-
My invention relates to machines designed to trim off the projecting ends of the
tenons upon the corners of wooden boxes, and consists in the improved features of
construction particularly described and claimed.
Reference is to be had to the accompanying drawings, forming part of this
Specification, in which
Figure 1 is a front elevation, of my improved machine. Figure 2 is a side
elevation of the same.
Figure 3 is a detail, illustrating the operation of the machine.
Figure 4 is a detail of the corner blocks upon which the box rests when being
trimmed, and
Figure 5 is a sectional detail of the knife.
In the drawings, A represents the frame of the machine, 2 the driving shaft
journaled thereon, carrying the idler belt pulley 3 and the fixed pulley 5 for the
driving belt 4, the belt being shifted from one to the other, by means of the shift
rod attachment 6, in the ordinary manner. The shaft 2 is fitted also with a
pinion 7 which meshes with the gear wheel 8 upon a shaft 9, provided with
eccentrics or crank discs 10 the pins of which are connected by means of the
connecting rods 11 with the cross-head 12. The cross head works upon vertical
guides 13 and is fitted with cutter heads 14 adjustable laterally along the same by
meaus of the screws 15 and 16 operated by the hand wheels 17 and 18. Each
cutter head is provided with a cutter or knife made up of the blades 26 and 28
secured at right angles with each other, as shewn, and having bevelled cutting edges
meeting at the angle formed by the two blades and bevelled on the outside, enabling
them to cut with a shearing action, as clearly shewn in Figure 3. The blades of
the cutter are made preferably wider than the thickness of the box boards and thus
project beyond and may come in contact with the face of the board if it is out of
line. To avoid gouging into the face of the board under such circumstances, I
prefer to form the blades of the knife with their faces slightly convex toward the
outer edges. Thus while the blades are perfectly plane-surfaced and at right angles
with each other for the full width of the joint, the portion of the blade which may
come in contact with the face of the box board flares or is turned slightly outward,
so as not to channel or gouge the board, as is clearly shewn in detail, Figure 5.
Secured upon the front of the frame is the cross-bar 20, having undercut bevelled
edges 23 to which are fitted the lugs 24 of the sliding tables 21 and 22, the lugs
being provided with set screws by means of which the tables may be secured at any
desired position along the guide, according to the size of the box to be worked
thereon. The tables have rear stops 25 and the table 21 has an end stop 27
against which the box is held when trimmed, as hereinafter described. Upon the
tables are fitted the corner blocks 29 having oppositely bevelled upper surfaces
leaving a small plane surface 31 only at the inner corner on which the corner of the
box rests, the blocks being secured in any desired manner upon the tables and in
such position that the knives in descending will fit closely to the sides of the block.
These blocks serve the double purpose of furnishing such a support for the box that
the upright corner of the box can be brought into perfectly vertical or plumb
position without regard to the angle between the sides and bottom of the box, in

page_text: case the bottom is out of true. The bevelled surface of the block serves as a
convenient guide upon which to slide the box up against the stops. The block also
serves, by being adjusted, to stand with its supporting corner just within the path
of the knife, to support the box corner and act as one blade of a pair of shears in
trimming the projecting ends of the tenons. An adjustable stop 30 may be arranged
to stand over the top of the box to prevent its being thrown upward by the return
movement of the knives, after being trimmed.
In operation, the tables 21 and 22 are set to the length or width of the box as
the case may be. The blocks 29 being secured in place upon the tables, the cutter
heads are then adjusted by means of their screws, so that the cutters will descend
close to the corners of the blocks 29. The box B is then slipped into place by
sliding it up the incline of the block 29 until in contact with the stops, the corners
resting upon the surfaces 31 of the blocks. The belt is then thrown on to the
pulley 5 whereby the shaft 9 and its eccentrics are turned so as to carry the knives
downward, trimming off the projecting ends of the tenons 32 on the corners of the
box with a shearing cut, as illustrated in Figure 3. The tops of the supporting
blocks 29, being bevelled off, offer no support for the box excepting upon the
surface 31. Thus any irregularities upon the bottom of the box will not serve to
throw the corners out of plumb.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
-
1. A right-angled tenon trimming knife having bifurcated cutting edges, one
face of each blade being slightly convex near the outer edge.
2. A right-angled tenon trimming knife, having diagonal cutting edges meeting
at the angle of the blades and extending to the outer edges of the blades, said
cutting edges being bevelled on the outside of the blades, and the face of each
being slightly convex near the outer edge.
3. In a device of the class described, the combination, with the box support, of
the cutter heads working to and from said support and the right angled bifurcated
knives carried by said heads, substantially as described.
4. The combination, with the box support, of the cross head working to and
from said support, the cutter heads laterally adjustable upon said cross head, and
the right-angled bifurcated knives carried by said cutter heads, substantially as
described.
5. In a device of the class described, the combination, with the supporting
frame, of the tables laterally-adjustable thereon, box supports upon said tables,
cutter heads working to and from said tables, and the corner cutting knives carried
by said cutter heads, the cutting edges of the knives aligning with the faces of said
stops, substantially as described.
6. In a device of the class described, a box corner support consisting of a
rectangular block having its top surface bevelled away from the box supporting
corner, substantially as described.
7. The combination, with a suitable supporting frame, of the tables laterally
adjustable thereon, the stops upon said tables, laterally-adjustable cutter heads
working to and from said tables, corner cutting knives carried by said cutter heads
with their cutting edges aligning with the faces of said stops and the rectangular
blocks upon said tables fitting against said stops having their top surfaces bevelled
away from the inner corner, substantially as described.
8. A box trimming machine, comprising in combination a support for the
corner of the box, stops for the adjacent sides of the box, a cutter head
working to and from said support, and a right-angled knife carried by said head
with its cutting edges aligning with the inner faces of said stops, substantially as
described.
9. A box trimming machine comprising in combination a rectangular block
serving as a support for the corner of the box, the top of said block being

page_text: bevelled away from the corner, stops for the adjacent sides of the box, and a
right angled knife working to and from said block with its cutting edges aligning
with the sides of the box when in bearing contact with said stops, substantially as
described.
10. A box trimming machine comprising in combination a support for the corner
of the box, stops for the adjacent sides of the box and a bifurcated right angled
knife, the fork forming the cutting edges of the knife, said edges aligning with
the sides of the box when in contact with said stops, substantially as described.
11. Means for trimming box corners comprising in combination a suitable cutter
head and two similar flat blades having diagonal cutting edges, and secured on
said head at right angles with each other with their shorter sides adjacent,
substantially as described.
12. In a device of the class described, the combination, with the frame of the
machine, of the box support, the cutter head working to and from said support,
the corner cutting knife carried by said head, the crank shaft journaled upon said
machine and connected to said cutter head, and means for applying power to said
shaft to operate said head, substantially as described.
13. The combination of the frame, the adjustable box supports provided with
stops, the cross-head working to and from said supports, the adjustable cutter
heads carried by said cross-head, the corner trimming knives carried by said
cutter heads the crank shaft journaled upon the frame of the machine and
connected with said cross-head, and means for connecting said crank shaft to a
source of power to operate said cross-head, substantially as described.
14. A box corner trimming knife comprising two similar flat blades having
diagonal cutting edges, and secured together at right angles with each other
whereby said edges operate with a shearing cut.
Dated this 1ot dow of Ma- 1904
Dated this 1
of May
1904
C. CRISTADORO,
By A. M. & Wm. Clark,
53, Chancery Lane, London, Chartered Patent Agents.