AU625727B2 - Improved engraving machine - Google Patents

Description

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7 2 7 COMMONWEALTH OF AUSTRALIA Patents Act 1952 C O MPLETE A F T E R P R OV I S I O N AL

SPECIFICATION

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(ORIGINAL)

Class Int. Class Application No Lodged Complete-After-Provisional Specification Lodged Accepted 0009o Published Priority Related Art g Name of Applicants Address of Applicants Actual Inventors Address for Service ROWLAND ARTHUR FABB AND WESLEY ROWLAND FABB 2 Seaview Parade, Lakeside Park, North Narrabeen, New South Wales, 2101, Commonwealth of Australia.

:ROWLAND ARTHUR FABB AND WESLEY ROWLAND FABB H.R. HODGKINSON CO Patent Trade Mark Attorneys 26a Alfred Street MILSONS POINT N.S.W. 2061 i ii Complete-After-Provisional Specification for the invention entitled: IMPROVED ENGRAVING MACHINE The following statement is a full description of this invention including the best method of performing it known to me:- 8 017019 030990 Li 'H I. THIS INVENTION relates to signboard engraving and more particularly to a new or much-improved stylus for a signengraving machine which utilises a router arrangement.

Sign-engraving machines of this type include an engraving bed in which can be clamped a workpiece, of timber or other suitable material, upon which the desired character is to be engraved; mounted above the engraving bed is an electricallydriven router which is able to be manually moved in three operating directions. Firstly, the router is movable vertically to enable the cutting head or bit to engage and disengage the surface of the workpiece; secondly, the router is movable in a direction parallel to the longitudinal axis of the workpiece; and thirdly, the router is movable in a S° direction normal to the second direction. Additionally, the 0"al router can be swung upwardly through an arc to enable access S to be had to the engraving bed, to change workpieces as necessary. The moving parts are arranged in low-friction bearing elements and it will be realised that, by combining the second and third directional movements, curvilinear o" 'oO letters and numbers and indeed any suitable design or insignia may be satisfactorily engraved.

Affixed to the router base-plate is at least one stylus arm, i extending towards the operator and terminating in a stylus block through which extends vertically a stylus, topped with a 25 hand-held knob, by means of which the pin, or point, of the stylus may be guided around the contours of a letter, number, or the like characters incised in a template. Each character to be engraved occupies an individual template, which may be ideally computer-ge ated. The appropriate templates are arranged side-by-side in a template tray in front of which the

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operator stands or sits. Thus, the router follows the operator.-guided stylus to engrave the desired characters on the workpiece.

Before the spinning cutter can be plunged into the board comprising the workpiece, the router arm must be secured so as to overcome the router's tendency to move in random directions, owing to the torque of the spinning cutter.

Previously this meant that the router arm would be lowered into the horizontal engraving position, to enable the stylus pin to be inserted into the template. The operator was then required to hold the router arm in place with one hand, and attempt to plunge the router head down so that its spinning o cutter would be plunged down into the timber with the other hand, locking the router in this position. The operator would 3. then engrave the image of the template, On completion, the cutter was then extracted from the timbei while the router S, itself remained secured in position by the stylus pin. This again entailed holding the router arm in position and, with the other hand, raising the router head on its own frame.

Only then could the operator remove the pin from the template and move onto the next template to be engraved. This cumbersome process must be repeated for each template, 2 t including plunging and un-plunging the router head.

l l It is therefore an object of the present invention to overcome the above and other disadvantages or at the very least to L .provide an alternative to previously known methods.

According to the present invention there is provided a stylus for a sign-engraving machine, the said stylus comprising a shaft having a point or pin attached thereto for guiding around a template, and a stylus block; the shaft having means 3 1 l 1 1 l i 1 1 1 1 11 associated therewith to allow for sliding engagement through the said block and means to restrict the upward movement of the shaft therethrough; so that in a first operating position the pin of the stylus may be guided around a template whilst downward pressure applied the stylus block keeps it a fixed distance from the workpiece, and in a second non-operating mode the stylus block may be slid up the shaft whilst keeping the pin in position in the template.

Preferably the means associated with the shaft to allow for sliding engagement comprise an externally-threaded bush screwable into a correspondingly-threaded bore in the stylus block and a lock-nut screwable onto the externally-threaded bush to position the latter with respect to the stylus block.

Also it is preferred that the means to restrict the upward i °I5. m-vement of the shaft through the stylus block is a locking o col.ar adapted to be clamped about the shaft to maintain a fixed distance between the block and the workpiece in the operating mode.

0 Therefore one embodiment of the invention is provided by a "8 stylus for a sign-engraving machine, the said stylus comprising an externally-threaded bush screwable into a ^o i correspondingly-threaded bore in a stylus block; a lock-nut screwable onto the externally-threaded bush to position the latter with respect to the stylus block; a shaft having a 1 point or pin attached thereto for guiding around a template, the shaft extending slidably through the said bush and the block; and a locking collar adapted to be clamped about the shaft and to abut the lower end of the bush when the stylus is in the operating position.

In order that the reader may gain a better understanding of the present invention, hereinafter will be described a preferred embodiment thereof, by way of example only and with reference to the accompanying drawings in which:- Figure 1 is a simplified side elevation of a signboard engraving machine; and Figure 2 illustrates,to a larger scale, a stylus according to the present invention.

Throughout the drawings, like elements are referenced by the same numerals.

00e Figure 1 shows a sign-engraving machine in simplified side elevation. It has an engraving bed 1 in which a piece of suitable workpiece material 2, destined to become an engraved o signboard, car, be clamped. An electric router head 3 which 19. may well be of 3 is mounted above engraving bed 1 in a spring-biased frame, schematically indicated at 4 comprising the router base-plate 6. The router head 3 is able to be moved vertically to enable the cutting head, or bit, 5 to be engaged with, and disengaged from, the surface of workpiece 2, So260 and to enable it to be withdrawn into router base-plate 6 as necessary.

The router base-plate 6 is mounted at the end of a router arm 7 and is able to be moved to-and-fro in the direction of arrow with respect to a back-beam 8 and carriage arrangement The back beam 8 is itself vertically adjustable, being mounted between the tracks of a pair of vertical guiding stanchions, as indicated at 9 in chain-line. Back-beam 8 supports the carriage 10 which is able to be moved along a track on the underside of back-beam 8 in a direction normal to direction i t 1 P 11 1 that is to say, towards and away from the eye of the viewer of Figure 1. The router base-plate 6 is therefore able to traverse in a two dimensional array over the engraving bed 1.

Affixed to router base-plate 6 is a parallel pair of stylus arms, as that referenced 11, which extend towards the operatr and which terminate in a stylus block 12 through which extends vertically a stylus in accordance with the present invention.

Below stylus block 12 there is a template tray 13 in which is clampable a suitable template. Router head 3, arm 7 and.

base-plate 6, together with affixed components can be swung upwardly through an arc indicated by arrow about pivot- 0:0)0~ point 14 of back-beam 8, to enable access to be had to engraving bed 1 and workpiece 2.

Figure 2 illustrates, to a scale larger than that of Figure 1, o @0 a stylus according to the present invention, in vertical cross-section.

The inventive stylus, generally referenced 20, comprises an 0 externally-threaded stylus bush 21 which is screwable into a 0.620 correspondingly-threaded bore 22 in stylus block 12 mounted at the operatorts end of a parallel pair of stylus arms, as that 000 referenced 11. Screwable onto externally-threaded stylus bush 00 21 is a lock-nut 23, the function of which is to vertically locate the bush 21 with respect to stylus block 12.

6 25 Extending slidably through stylus bush 21, and hence through stylus block 12, is a stylus shaft 24, upon the upper end of which is a hand-held knob 25, by means of which the router head 3 (see Figure 1) may be moved two dimensionally in the horizontal plane. The lower end of stylus shaft 24 terminates in a pin 26 which is able to be hand-guided around the contours of a character, such as a letter, or number, incised at 27 in a template 28 adapted to be clamped in a template tray 13 (see Figure At a location below stylus bush 21, which extends through stylus block 12, there is a locking collar 29 adapted, via a grub-, or set-screw 30, to be able to be clamped about stylus shaft 24 so as to abut the lower end of externally-threaded stylus bush 21 when the stylus 20 is in its operating position as shown in Figure 2.

Thus it will be realised that, when the router head 3 and its adjuncts are swung upwardly, shaft 24 is able to move downwardly through stylus bush 21 without let or hindrance 0 0 0 .0 *until, if necessary, knob 25 "sits" on the upper end of bush

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oo 0 0 When the router is swung downwardly, collar 29, locked as it Sis on shaft 24, ensures the integrity of the space indicated by arrow that is to say, the distance between the upper surface of template 28 and stylus block 12 remains constant.

Thus, the router is able to be plunged to the correct cutting 0 0' depth and set (no workpiece being in place or to the side a thereof if one is in position). Once achieved, the router may then be turned on and moved into position above the material S to be engraved, the router arm being inclined upward toward the operator. As the stylus is able to slide down through the bush, the pin may be lowered and secured in the template, and thus the router arm and consequently the router head and cutter, are secured in position while still being above the work surface. When operating, it is merely necessary to lower the router arm down to the horizontal engraving position (i.e.

against the locking collar) thereby causing the spinning router cutter to be inserted into the timber. The operator

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it i -i then simply copies the templates image, and moves to the next template by keeping a downward load on the stylus so that the pin remains located securely in the template, whilst raising the router arm so that the router cutter is automatically removed from the timber.

Therefore, by using the invention much time may be saved by the operator. This is consequent to the new stylus being movable relative to the stylus arm, thereby aLlowing-thestylus to slide down through the bush and be inserted into the template groove before the router arm is lowered into the engraved position. Accordingly, the router may be lifted in its plunged position with the cutter protruding below the router base plate. This means that when the arm is lowered to its horizontal engraving position the cutter is automatically t; e inserted into the engraving surface.

i From the foregoing, it will be readily appreciated by those skilled in the art that numerous variations and modifications may be made to the invention without departing from the spirit and scope thereof as described hereinbefore.

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Claims (4)

1. A stylus for a sign-engraving machine, the said stylus comprising a shaft having a point or pin attached thereto for guiding around a template, and a stylus block; the shaft having means associated therewith to allow for sliding engagement through the said block and means to restrict the upward movement of the shaft therethrough; so that in a first operating position the pin of the stylus may be guided around a template whilst downward pressure applied the stylus block keeps it a fixed distance from the workpiece, and in a second non- operating mode the stylus block may be slid up the shaft whilst keeping the pin in position in the template. o

2. A stylus for a sign-engraving machine according to claim "o 1, in which the means associated with the shaft to allow for sliding engagement comprise an externally-threaded bush screwable into a correspondingly-threaded bore in the stylus block and a lock-nut screwable onto the externally-threaded bush to position the latter with respect to the stylus block. o o 0

3. A stylus for a sig'i-engraving machine according to either pnl ~claim 1 or claim 2, in which the means to restrict the upward movement of the shaft through the stylus block is a locking collar adapted to be clamped about the shaft to maintain a fixed distance between the block and the workpiece in the operating mode.

4. A stylus for a sign-engraving machine, the said stylus comprising an externally-threaded bush screwable into a 9 ll 12'; 3 correspondingly-threaded bore in a stylus block; a lock-nut screwable onto the externally-threaded bush to position the latter with respect to the stylus block; a shaft having a point or pin attached thereto for guiding around a template, the shaft extending slidably through the said bush and the block; and a locking collar adapted to be clamped about the shaft and to abut the lower end of the bush when the stylus is in the operating position. A stylus for a sign-engraving machine substantially as disclosed herein in conjunction with the drawings. Dated this 13th day of April 1992 o ROWLAND ARTHUR FABB AND WESLEY ROWLAND FABB 4 BY: 4'1 Y oo Attorneys for the Applicants h i "i