Note: Descriptions are shown in the official language in which they were submitted.
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SPECIFICATION
FIELD OF THE_INVENTION
This invention relates to movable head band saws and,
more particularly, to a head mounting system permitting angled
or mitre cuts without special orientation of the workpiece.
DESCRIPTION OF THE PRIOR ART
Movable head band saws are commonly used for cutting
pieces off longer pieces of rolled, drawn, of extruded stock
material They may be divided into three basic types,
lo The first type, commonly known as the scissors type
cut-off saw, is so named because the head of the band saw is
pivotally raised and lowered, relative to the work area, in
a scissors motion. ~uring the downstroke, the scissors motion
of the cutting portion of the blade cuts through the workpiece.
The second type of movable head band saw may be
referred to as a vertical feed saw because it employs one or two
posts, which guide the head of the saw as it is vertically raised
or lowered with respect to the work area, The motion of the head
is a straight line translation with the head remaining
horizontal
The third type of movable head band saw is commonly
referred to as a tilt head saw, In this type, the head is
carried on a movable carriage fitted to a carriage way system
which permits horizontal translation of the carriage and head,
forwards and backwards, through the work area. The head is
attached to the carriage by a pivotal connection, with pivot
parallel to carriage translation, permitting the entire head and
cutting portion of the blade to be tiited out of the vertical
plane for making an angular cut in the workpiece as the head and
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cutting portion of the blade are moved through the workpiece by
the translation of the carriage.
These three types of movable head band saws are used primarily as
"cut-off" saws for cutting pieces off relatively long work pieces,
such as lengths of structural steel In some kinds of work, as
in frame construction, angular or mitre cuts are frequently
required. In the scissors and vertical feed types of band saws,
angle cut capability has been provided by special workpiece vises
in which either the whole vise, or its two jaws only, may be
pivotally adjusted about a vertical axis, or axes, before
the workpiece is clamped. In this way the workpiece may be held
with its longitudinal axis at the desired angle to the cutting
plane of the band saw Unfortunately, because workpieces are
usually long and are frequently fed to the saw by roller tables,
this method of making angle cuts is often impractical.
As has been mentioned, the tilt head type band saw
permits angle cuts without reorientation of the workpiece,
However, because of structural requirements associated with
the movable carriage, and the need for a power carriage drive,
tilt head band saws are characteristically large, heavy, and
expensive machines.
It is, therefore, a~ object of the invention to provide
a head mounting means which will enable scissors and vertical
feed band saws to make angle cuts economically, and without
reorientation of the workpiece,
According to the invention, the head of the band saw is
mounted on a rotatable subframe which is itself pivotally mounted
to the base of the saw, The axis of the subframe pivot is
vertical and is adjacent the front edge of the fixed jaw
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of the workpiece vise which is rigidly mounted to the work table
portion of the saw base. A locking means is interposed between
the rotatable subframe and the saw base so that the angular
relationship between them may be selectively set.
The rotatable subframe lies substantially below
the work table such that, within its range of angular adjustment,
it does not encroach upon the workpiece area
In the form in which the invention is applied to
the scissors type band saw, the moving head is connected to
the rotatable subframe by a horizontal pivot lying perpendicular
to the cutting plane, in the same manner as the moving head is
connected to the saw base in a conventional scissors type band
saw.
The rotatable subframe pivot may be located such that
it lies in the plane of the fixed jaw of the workpiece vise, and
the geometry of the head and rotatable subframe may be made such
that the cutting plane contains the vertical projection of
the subframe pivot. Thus, regardless of cutting angle,
the cutting plane passes through a fixed point in the plane of,
and adjacent the front edge of the fixed jaw of the workpiece
vise, affording simple and accurate length of cut setting, as well
as uniform support of the workpiece.
In the form in which the invention is applied to
the vertical feed type band saw, the rotatable subframe has two
lateral extensions which support the lower ends of the vertical
posts which support and guide the movable head. These extensions
are configured, and the posts located, so that they do not
encroach on the workpiece area. As in the scissors type saw,
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the cutting plane contains the vertical projection of the subframe
pivot.
The manner in which these two forms of the invention
achieve the object will be apparent fro~ the following
description and accompanying drawings,
Figure 1 is a schematic profile view of a conventional
scissors type movable head band saw.
Figure 2 is a schematic profile view of a conventional
vertical feed type movable head band saw,
Figure 3 is a schematic profile view of a tilt frame type
movable head band saw,
Figure 4 is a schematic side view of a tilt frame type
movable head band saw,
Figure 5 is a schematic plan view of a scissors type
movable head band saw incorporating a swing head
~ounting in accordance with the present
invention. showing particularly the head swing
and resulting angle cutting capability,
Figure 6 is a schematic profile view of the machine
depicted in Figure 5,
Figure 7 is a schematic profile view of a vertical feed
type movable head band saw incorporating a swing
head mounting in accordance with the present
lnvention,
Figure 8 is a schematic plan view of the machine of
Figure 7 showing particularly the head swing and
resulting angle cutting capability,
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DETAILED DESCRIPTION OF THE PREFERRED ~MBODIMENTS
With reference to Figure 1, the scissors type movable
head band saw 1, comprises base 2, work table 3, fixed and
movable work piece vise jaws, 4 and 5 respectively, and further
comprises movable head 6 carrying driving and driven band wheels.
7 and 8 respectively. Movable head 6 is pivotally connected to
base 2 by pivot axle 9 which is parallel to the line formed by
the intersection of the plane of the work table 3, and the plane
of the fixed workpiece vise jaw 4, such that movable head 6 is
permitted to move pivotally, in the direction of arrow 11, in
a plane perpendicular to said line. Cutting band 12 is trained
in tension around driving and driven band wheels 7 and 8, and is
twisted by band guides (not shown for clarity) so that its
cutting teeth are directed towards the work area 13 and
the cutting portion 15 of the cutting band 12 lies in the plane
of motion of the movable head 6. Workpiece 14 is supported by
work table 3 and held firmly in place by fixed and movable vise
jaws 4 and 5, such that, for a parallel sided workpiece,
the workpiece longitudinal axis is parallel to pivot axle 9.
Thus when cutting portion 15 of the cutting band 12 is carried
through the work area 13 by the motion of the movable head 6,
the workpiece 14 is cut off on a plane perpendicular to its
longitudinal axis
With reference to Figure 2, the vertical feed type
movable head band saw 21, comprises base 22, work table 23, fixed
and movable workpiece vise jaws 24 and 25 respectively, and
further comprises movable head 26 carrying driving and driven
band wheels 27 and 28 respectively. Movable head 26 is connected
to the base 22 by head guides 29 and 30 which constrain
the movable head 26 to vertical motion, indicated by arrow 31, in
a plane which is mutually perpendicular to the plane of the work
table 23, and the plane of the fixed workpiece vise jaw 24.
Workpiece 32 is supported by work table 23 and held firmly in
place by fixed and movable workpiece vise jaws 24 and 25 such
that, for a parallel sided workpiece, the workpiece longitudinal
axis is perpendicular to the plane of the motion of the movable
head 26, Cutting band 33 is trained in tension around driving
and driven band wheels 27 and 28 and is twisted by band guides
lQ (not shown for clarity) so that its cutting teeth are directed
towards the work area 34 and the cutting portion 35 of the cutting
band 33 lies in the plane of motion of the movable head 26. Thus
when cutting portion 35 of cutting band 33 is carried through
the work area 34, by the motion of the movable head 26,
the workpiece 32 is cut off on a plane perpendicular to its
longitudinal axis.
With reference to Figures 3 and 4, the tilt frame type
movable head band saw 41, comprises movable head 42 which is
pivotally connected by pivot axle 43 to carriage 44, such that
movable head 42 is permitted to move pivotally, in the direction
of arrow 60, in a plane parallel to the plane of the saw front 47
The carriage 44 is slidably supported, through way bars 45, by
base 46, such that carriage 44 and movable head 42 are permitted
to move toward and away from saw front 47, in the direction
indicated by arrow 48 Movable head 42 carries driving and
driven band wheels 49 and 50 respectively, about which cutting
band 51 is trained in tension. Cutting band 51 is twisted by
cutting band guides 52 and 53 so that its cutting teeth are
directed toward the worX area 54, and the cutting portion 56 of
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the cutting band 51 lies in a vertical plane which is parallel to
the line of movable head motion, and mutually perpendicular to
the planes of the work table 55 and the fixed workpiece vise
jaw 57
To make a cut, driving band wheel 49 is caused to
rotate, and movable head 42 is advanced to carry cutting
portion 56 of cutting band 51 through the workpiece 59 which is
supported by work table 55, and held firmly in place by fixed and
movable workpiece vise jaws 57 and 58 For a parallel sided
workpiece, the resulting cut is on a plane perpendicular to its
longitudinal axis.
By means of pivot axle 43, the movable head 42 may be
selectively tilted out of the vertical plane such that, as
the movable head 42 is moved through the work area 54, as angular
cut is made through the workpiece 59.
With reference to Figures 5 and 6, the improved
scissors type movable head band saw 61 is similar to that in
Figure 1 except that a rotatable subframe 62 is interposed
between the movable head 63 and the base 64. Movable head 63 is
pivotally connected, by horizontal pivot axle 65, to rotatable
subframe 62 which is itself pivotally connected to base 64 by
the vertical subframe pivot axle 66, As with the conventional
scissors type band saw, horizontal pivot 65 permits movable
head 63 to rotate in the direction of arrow 67 for the purpose
of carrying cutting band 68 through the workpiece 69 and thus
- making a cut.
Subframe pivot axle 66 permits the movable head 63 to
be selectively rotated in the direction of arrow 70 such as to
permit angled cuts without reorientation of the workpiece 69.
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Subframe pivot axle 66 is located such that its axis lies in
the plane of, and adjacent the front edge of, the fixed
workpiece vise jaw 71, while the geometry of the movable head 63
and the rotatable subframe 62 is such that the cutting plane
contains the vertical projection of the subframe pivot.
A locking device 72, is interposed between the pedestal
subframe 62 and the base 64 in order to maintain the desired
angle of cut.
With reference to Figures 7 and 8, the improved
vertical feed type band saw 81, is similar to that in Figure 2
except that a rotatable subframe 82 is interposed between
the lower ends of the head guides 83 and 84, and the base 85. As
with the conventional vertical feed type band saw, the head
guides 83 and 84 permit the movable head 86 to translate
vertically, in the direction on arrow 87, for the purpose of
carrying cutting band 88 through the workpiece 89 and thus making
a cut.
Rotatable subframe 82 is pivotally connected to base 85
by the vertical subframe pivot axle 90 which permits the movable
head 86 to be selectively rotated in the direction of arrow 91
such as to permit angled cuts without reorientation of
the workpiece 89. Subframe pivot axle 90 is located such that
its axis lies in the plane of, and adjacent the front edge of,
the fixed workpiece vise jaw 92, while the geometry of
the movable head 86 and the rotatable subframe 82 is such that
the cutting plane contains the vertical projection of
the subframe pivot.
A locking device 93, is interposed between
the rotatable subframe 82 and the base 85 in order to ~aintain
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the desired angle of cut.
