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(11) | EP 0 202 006 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Apparatus for the cutting of halving joints |
| (57) @ The invention is concerned with apparatus for cutting accurately profiled notches
in wooden glazing bars (2,4) and the like. The apparatus illustrated by way of example
comprises a machine frame including a work table (18), clamping means (28) to retain
a bar in position on the table which is advanced towards a plurality of sets of cutting
means (12,14,16) arranged at adjustably spaced locations along the table so that a
plurality of cuts or notches (6,8) is formed simultaneously in the bar. Advantageously,
a hopper feed arrangement may supply a sequence of bars in an end-to-end manner for
operation by the apparatus. |
[0001] The invention is concerned with improvements in or relating to bar cutting particularly to the joint cutting of window and door bars.
[0002] In the production of windows, panelled doors and the like, it is conventional practice to manufacture bars or lengths of wood having a desired cross-section and to form notches in the bars to enable two lengths of bar to interengage and form a cruciform joint, hereinafter referred to as halving joint. Accurate cutting of these notches is necessary to enable for example a wooden window frame to be correctly assembled ready for glazing.
[0003] The invention provides apparatus for the cutting of halving joints and the like comprising a machine frame including a work table, means to position a length of bar to be cut upon said table and means to present the work table and the bar to operating instrumentalities of the apparatus through relative movement therebetween, wherein said operating instrumentalities comprising a plurality of cutting means arranged at spaced locations along the work table and capable of simultaneously forming a plurality of cuts in the bar ; at selected intervals along the length thereof.
[0004] Advantageously, each cutting means comprising three cutting wheels operating in a desired sequence, all the cutting means following the sequence in a simultaneous manner.
[0005] In an example of apparatus according to the invention, provision may be made to reverse the direction of rotation of at least one of cutting wheels in order to preserve a clean cut into one or other surface of the bar as selected.
[0006] Preferably, means are provided for adjusting the spacing between the cutting means according to the required intervals of distance between the notches to be cut in the bar, depending on the design and size of the window or door panel frame to be manufactured. Conveniently, the work table is provided with slots formed along the path of operation of each cutting means when the table is presented thereto, and provision is made to adjust the position of said slots as required.
[0007] It will be understood that while each bar may be manually placed upon the work table and positioned thereon by clamps, it is also now made possible to load bars automatically onto the table from a supply device, for example a hopper feed, so that each bar is fed lengthwise beneath raised bar clamping devices until a movable end stop is reached. After cutting the notches in the clamped bar, the end stop is removed, the clamps raised and the next bar is loaded. Conveniently, the advance of the next bar causes the preceding bar to be removed from the work table.
[0008] There will now be described with reference to the drawings example of an apparatus according to the invention. It will be understood that the description is given by way of example only and not by way of limitation.
[0009] In the drawings;
Figure 1 illustrates notches to be formed on a window bar
Figure 2 is a side view of a notched bar
Figure 3 is a cross-section on line III-III of Figure 2
Figure 4 is a side view of the apparatus with covers partly removed to show the cutting means
Figure 5 is a plan view of a work table of the apparatus; and
Figure 6 is a side view of a bar clamped in position on the table of Figure 5.
[0010] Two wooden window bars 2,4 are illustrated in Figure 1. Each has a generally T-shaped cross-section and in order to form a cruciform joint has been notched for interengagement. Each bar has received three cuts, as shown on bar 4 at 6, 8 and 10 (see Figures 2 and 3).
[0011] Figure 4 shows apparatus arranged for cutting four such notches simultaneously in a length of window bar 4. Notch cut 6 is to be made by a cutting wheel 12, notch cut 8 by a cutting wheel 14 and notch cut 10 by a saw blade 16. Four sets of the cutters 12, 14 and 16 are adjustably arranged along their driving spindles (not shown) to be driven by motors (not shown) having a total output of 12 Kw at a spindle speed of 6300 r.p.m. The paths of each set of cutters are shown in Figure 5 at A, B, C and D. The spacing between the paths of four sets of cutters 12, 14 and 16 is determined by the desired distance between the notches on the window bar 4. It will be understood that the numbers of cutters is also determined by the design of the window i.e. the number of bars 4 incorporated therein.
[0012] To obtain the greatest possible degree of support for the bar 4 during operation of the four sets of cutters the bar is supported upon a work table 18 of the apparatus which is arranged to be advanced toward the cutters 12, 14, 16. The portions of the bar to be notched lie across slots 20 in the table 18. While these slots may be simply milled into the table at suitable standard positions, it is particularly advantageous if the position of the slots may also be adjusted so as always to lie on the paths A-D, (Figure 5). In the present example therefore the leading edge of the table 18 is comprised by segments 22 received in a T-slot 24 of the table, the length and position of the segments being selected as required.
[0013] In the example a locating groove 26 of the table 18 is provided in each segment 22 so as to receive a shoulder portion of the cross-sectional area of the bar 4 (see Figure 6). The bar 4 is received beneath clamps 28 positioned at locations between neighbouring slots 20. Advantageously, each clamp 28 is capable of adjustment lengthwise of the table to accommodate the position of the segments 22. The clamps 28, which are pneumatically operated, are movable between a raised, retracted position and an extended lowered position illustrated in Figure 6. In addition, the operating position of the cutters may be adjusted in unison by a cam-operated adjustment means (not shown) so as to accommodate bars of various cross-sectional areas.
[0014] The operation of the apparatus shown in the Figures will now be described. The operating cycle of this apparatus is 12 seconds.
[0015] With the work table 18 in the position shown in Figure 6 and in full lines in Figure 4, a bar 4 is loaded thereon so as to be received in the groove 26 of the segments 22. These segments have been arranged to provide slots 20 on the paths A-D, and the four sets of cutters 12, 14 16 have been positioned so that the four notches to be formed are in the correct relative positions. The bar 4 is positioned against an end stop (not shown) to one side of the table as viewed in Figure 5. A safety cover 30 (Figure 4) is then lowered and the operator must then simultaneously operate two start buttons 32 for safety reasons.
[0016] The clamps 28 then advance and are lowered to clamp the bar 4 as shown in Figure 6. The work table 18 is then advanced as shown by the arrow E in Figure 6 until the portions of the bar 4 which bridge the slots 20 contact the wheels 12 and 14. Further advance of the table under the influence of an adjustable hydraulic damping valve arrangement thus results in the cuts 6 and 8 being formed and brings the bar into contact with the saw edge 16 to form the cut 10.
[0017] It will be appreciated that the set and direction of rotation of the cutter teeth may be reversed if desired. This is because the edge cut on entry of the cutter or saw teeth is often cleaner than the exit edge and the appearance of one surface of the finished window may be visually more important as selected.
[0018] Operation of a trip switch S1 by the advanced table causes the table to be withdrawn until a further trip switch S2 operates to halt the table in its original position and to release the clamps 28. A mitring operation on the ends of the bar 4 renders it ready for assembly with others into a window frame. This is achieved by the additon to the device of so-called scribing heads (not shown) which shape the ends of the bars to be received in the peripheral frame of the window.
1. Apparatus for the cutting of halving joints and the like comprising a machine frame
including a work table, means to position a length of bar to be cut upon said table
and means to present the work table and the bar to operating instrumentalities of
the apparatus through relative movement therebetween, wherein said operating instrumentalitities
comprising a plurality of cutting means arranged at spaced locations along the work
table and capable of simultaneously forming a plurality of cuts in the bar at selected
intervals along the length thereof.
2. Apparatus as claimed in claim 1, wherein there is provided a plurality of adjustable
clamping devices each adapted to move between a bar-clamping and a retracted position.
3. Apparatus as claimed in either one of claim 1 and 2, wherein the table is provided
with a plurality of slots, each slot being formed along the path of operation of one
of said cutting means.
4. Apparatus as claimed in claim 3 wherein provision is made for adjusting the positions
of said slots and of the associated cutting means with respect of said table.
5. Apparatus according to claim 4, wherein side walls of said slots are defined by
side edges of segmented table edge portions arranged for adjustable location along
a leading edge of the work table.
6. Apparatus as claimed in claim 1, wherein each cutting means comprising three cutting
wheels operating in a desired sequence, all the cutting means following the sequence
in a simultaneous manner.
7. Apparatus as claimed in either one of claims 1 and 6, wherein means are provided
for adjusting the spacing between the cutting means according to the required intervals
of distance between the notches to be cut in the bar.
8. Apparatus as claimed in claim 6, wherein the number of spaced locations at which
cutting means are arranged is adjustable.
9. Apparatus as claimed in any one of the preceding claims, wherein the work table
is provided with slots formed along the path of operation of each cutting means when
the table is presented thereto, and provision is made to adjust the position of said
slots as required.
10. Apparatus as claimed in any.one of the preceding claims, wherein means are provided
to supply a plurality of bars in end-to-end sequence to said operating instrumentalities,
a bar which has been cut being removed from the table as the next bar is advanced
by the supply means.
11. Apparatus as claimed in claim 10, wherein the supply means comprises a hopper
feed device adapted between operations of the apparatus to supply the next bar to
the table, there being provided retractible end stop means to determine the correct
position of the bar on the table.
12. Apparatus as claimed in any one of the preceding claims, wherein means are provided
to advance the table towards and away from the operating instrumentalities, there
being a series of trip switch means positioned in the path of the table to control
its movements.
13. Apparatus as claimed in any one of the preceding claims, wherein the operating
instrumentalities further include scribing heads adapted to operate on end portions
of a bar.