GB2336564A

GB2336564A - Hand tool machine, in particular a jig saw

Info

Publication number: GB2336564A
Application number: GB9908928A
Authority: GB
Inventors: Konstanz Fux
Original assignee: Scintilla AG
Current assignee: Scintilla AG
Priority date: 1998-04-21
Filing date: 1999-04-19
Publication date: 1999-10-27
Anticipated expiration: 2019-04-19
Also published as: DE19817656B4; FR2777487A1; GB2336564B; GB9908928D0; DE19817656A1

Abstract

A motor-driven hand tool (10), in particular a jig saw, has a longitudinal axis X-X, comprises a motor housing (11), which has at its front end a gear case (12) with a tool (15) and is connected to a base plate (26). The motor housing (11) with the tool (15) is supported on a guide element (20) so as to be capable of swivelling about an axis Y-Y, which is directed substantially at right angles to the longitudinal axis X-X. The guide element (20) is fastened releasably to the base plate (26). The tool 15 may be eg a saw blade or a milling tool.

Description

2336564 1 Hand tool machine. in particular a Jig saw

Background art

The invention relates to a hand tool machine, in particular to a jig saw according to the type of claiin 1.

A device for supporting and guiding a hand tool machine, in particular a milling machine, comprising a base plate and a support is known from AT 000 18 1.

A slide, which is inclined at an acute angle of 30' to 40' relative to the base plate, is guided on the support. The slide is adjustable into diffirent positions and lockable.

The machine carrying and driving the tool is releasably connected to the slide. The device, which is intended mainly for producing flutes and grooves, is of a complex construction as well as being difficult and inconvenient to handle; base plate and support, both individually and Mi combination with one another, have to be stable enough to support the machine securely and accurately also in different positions of the slide. FurtherTnore, as a result of the non-variable inclination of the tool, only cuts and milling operations extending obliquely relative to the workpiece surface are possible.

In affig saw for machining corners, which is known from US-PS 4 566 190, a saw blade is mountable in three different positions at the foremost point in working direction on a special chuck. The drawback here is that, depending on the tracking of each cut, the saw blade has to be clamped into a new position on the chuck. In addition, a complex mechanism is required for transmitting and converting the rotary drive motion into the linear oscillating motion of the saw blade.

A corner saw, wherein the saw blade is fastened to an arM which is disposed on a component which oscillates in longitudinal direction of the saw blade, so as to be slewable and adjustable on said component, is disclosed by US-PS 5 535 2 520. Saw blade and component are aligned parallel to one another and at right angles to the arm. The length of the arm is such that, when the arm is suitably adjusted in longitudinal or transverse direction relative to the housing, the saw teeth protrude beyond the housing. Although the object of said saw is to effect surface-flush sawing right into the outermost corners of workpieces, the means of fastening the saw blade to the arm always project beyond the tips of the teeth by a small amount, thereby precisely preventing achievement of the object and making it hinpossible to saw accurately right into a corner or angle. Said corner saw moreover has the added drawback that, each time the cut tracking is changed, it is first necessary to disconnect the saw, readjust the arm with the tool and reset the saw before the desired cut may be tracked.

Advantages of the invention The hand tool machine according to the invention having the charactefizing features of claim 1 is of a simpler construction, easier to operate and easily adaptable to other motor-driven hand tools.

By virtue of inserting an intermediate part, the fork-shaped guide element, between the hand tool and its base plate, manipulation of the tool during cutting or milling operations is advantageously avoided.

Guide element and retaining piece may advantageously be lightweight sheetmetal parts which are easy to manufacture.

The swivelling range of the retaining piece is in an advantageous manner adjustable depending on the distance of the front surface of the hand tool from the front surface of the actual cutting or milling tool and should generally be below 30'.

For cuts, which are to be tracked precisely along the apex line in the angle of preferably 90' between two surfaces, it is advantageous to remove the base plate and guide the hand tool along the wall surfaces, which form the angle, with the 3 aid of two oppositely disposed guide faces on the guide element. For said purpose the guide element which is fork-shaped in cross section, comprises a middle part, to which the base plate is fastened and which is aligned parallel to the base plate. Adjoinffig said part are two guide parts, which are provided with the guide faces and preferably include an angle of 45' with the middle part and an angle of 90' with one another. Each guide part is adjoined, in cross section, by a bearing part at an angle of 45', wherein the two bearing parts are preferably aligned parallel to one another and disposed at the front end of the hand tool.

Between the bearing parts a carrier is pivotally supported on bearing pins, which are inserted or screwed into the bearing parts, and is arrestable in the end positions of its swivelling range.

The arresting means are advantageously disposed on the fork-shaped guide element.

The arresting means, which holds the carrier in the position parallel to the middle part and optionally to the base plate, is a retaining piece, which is displaceable parallel to the middle part of the guide element and cooperates with a locking key. In one position of the retaining piece, the free end of the carrier projects into the retaining piece, in the other position said free end is released so that it may be pressed manually with the hand tool against a stop element fastened to the middle part. In said position the tool may operate, i.e. cut or mill, unimpeded and flush with the wall in the angle between two walls situated approximately at right angles to one another.

Drawings There now follows a detailed description of the invention with reference to the diagrammatic drawings of an embodiment of a jig saw. Said drawings show:

4 Figure 1 a side view of the jig saw according to the invention in normal position; position; Figure 2 a side view of the jig saw according to the invention 'm tilted Figure 3 a front view of the jig saw according to the invention, with base plate removed, during angular cutting; Figure 4 a plan view of the base plate; and Figure 5 a side view of the base plate according to Figure 4.

1 o Description of the embodiments

Figures 1 to 3 show a motor-driven jig saw 10 having a motor housing 11, which is designed as a handle with a longitudinal axis X-X and to which is attached at the front - i.e. in the forward feed direction indicated by an arrow 13 - a gear case 12. Projecting out of the gear case 12 is a holder 14 for a saw blade 15, which has a toothed side 15' and is set back relative to a front surface 16 of the gear case 12 by a distance a, which is determined by the wall thickness of the gear case 12 as well as by the construction and position of the gear unit (not shown) situated in the gear case 12. The saw blade 15 projects down through a base-plate 26, on which the jig saw 10 is slidingly supported and guidable over a workplece 3 6 (Figure 2).

In the position of the iig saw 10 shown in Figure 1, no clean, edge-flush sawing of the box-shaped workpiece 36 is possible further than across the distance a, because there the front surface 16 of the jig saw 10 butts against the box edge and prevents follow-up of the saw blade 15. The invention sets out to eliminate said drawback during the sawing or cutting operation. To said end, the handle- like motor housing 11 is rigidly connected, e.g. screw-connected, to a flat carrier 17 extending parallel to the longitudinal axis X-X.

The carrier 17 is provided at the front end with tab-like regions offset at right angles (Figure 3)), which serve as bearing shells 171, 172. The bearing shells 171, 172 are supported on two axle journals 18, 19 'm a fork-shaped guide element so as to be capable of swivelling about an axis Y-Y. The axis Y-Y extends in parallel to the guide element 20 and at right angles to the longitudinal axis X-X.

The carrier 17 is adjustable in that it is capable of swivelling about the axle journals 18, 19 so that its free, rear end is in a respective one of two stop positions against two stops 21, 22. The stops 21, 22 are disposed on the guide element 20. The one stop 21 is formed by a retaining piece 23, which is capable of swivelling about an axis 23' extending at right angles to the base plate 26 and which carries a locking key 24 used for manual operation. In a first swivelling position of the retaining piece 23 about the axis 23' according to Figure 1, the rear end of the carrier 17 engages into an annular groove (not specified) of the retaining piece 23 and is held fast by the annular groove flanks in such a way that it is prevented from is yielding upwards or downwards. The annular groove or the annular groove flanks extend eccentrically relative to the axis 2Y, wherein in the swivelling position according to Figure 2 the retaining piece 23 with the key 24 is swivelled into the drawing plane, so that the groove flanks may no longer form a stop for " the rear end of the carrier 17 and the latter, tilted down through approximately 10', is supported against the bottom stop 22.

In said position of the carder 17, a point A of the toothed side 15' of the saw blade 15 in an extension of the base plate 26 projects beyond the front surface 16 so that the saw blade 15 cuts right through the workpiece 36 as far as the wall 34, without the front surface 16 previously butting against the wall 34 and thereby 25 preventing cutting.

The distance a, by which the toothed side 15' is set back'relative to the front surface 16 and which is present in the normal position of Figure 1, is therefore fully compensated by tilting the carrier 17 about the swivelling axis Y-Y situated 6 above the base plate 26. In said case, 'm the stop position of the carrier 17 against the stop 22 it is possible to dispense with a locking device because the carrier 17 is reliably pressed down onto the stop 22 by the operating pressure exerted upon the motor housing 11 of the jig saw 10 during sawing.

According to Figure 3 the base plate 26 of the jig saw 10 is removed, wherein the front view reveals that the fork-shaped guide element 20 is formed symmetrically relative to a plane E-E and, for example, comprises a shaped sheetmetal part, a middle part 25 of which extends parallel to the base plate 26 and is releasably connectable to the latter with the aid of straight pins 37 and/or screws 38 10 (only one of which is shown) or in some other way.

The middle part 25 of the guide element 20 is adjoined on either side, symmetrically relative to the plane E-E, by two guide parts 27, 28 with outer-lying guide faces 271, 28 1, which verge into two bearing parts 29, 3 0 situated 'm the vicinity of the gear case 12. The guide parts 27, 28 are inclined by 45' relative to the middle part 25 and by 90' relative to each other. The bearing parts 29 and 30 are aligned parallel to one another and offset at an angle of 45' relative to the guide parts. They have threaded bores 31, 32, into which pins 181 and 191, which are provided at their front ends with the axle journals 18, 19 for the carrier 17, are screwed and held locked against rotation.

By means of the guide parts 27, 28 the jig saw 10, with the base plate 26 removed, is supportable inclined through 45' relative to walls or wall parts 33, 34 of the workpiece 36 against said walls or wall parts, wherein the jig saw blade 15 is guided exactly to the point where the wall parts 33, 34 meet approximately at right angles in an edge 35.

Prior to use of the jig saw 10 according to the invention in accordance with Figure 3, the base plate 26 has to be removed from the guide element 20 after loosening the screws 38 and the jig saw 10 has to be positioned with the guide element 20 on the workpiece 36 in such a way that the guide faces 271, 281 of the 7 guide parts 27, 28 come to fit snugly against the surfaces of the wall parts 33, 34. By displacing the jig saw 10, with the saw blade 15 'm operation, parallel to the edge 35 directed in Figure 3 at right angles to the drawing plane, the desired corner, edge or mitre cut is efFected and in the process it is guaranteed that the saw blade 15 always moves along the edge 35.

As Figure 4 reveals, the base plate 26 is provided with a recess 39 for unimpeded passage of the saw blade 15. The plane E-E is shown in Figure 3 directed at right angles to the drawing plane. It therefore follows that said plane extends parallel to the drawing plane in Figures 1 and 2 and fornis the plane of symmetry of the illustrated embodiment.

Instead of the jig saw 10 it is possible to use a milling tool or an abrasive cutting tool which may, for example, be provided with at least one separately formed handle.

The carrier 17 and the guide element 20 are restricted to their described basic fimction but not to the forms of the embodiment. It is alternatively possible to arrange the jig saw 10, without a separate carrier 17, so that it is supported in the guide element 20 so as to be capable of swivelling about the axis Y-Y, which would however require modifications to be made to the housing of the jig saw 10.

In a non-illustrated application of the jig saw according to the invention, in a box-shaped workpiece the box base is to be sawn diagonally 'm a flush manner right into the corner of the box, in which case the jig saw may be adjusted relative to the base plate Mi accordance with Figure 2 so that the saw blade may operate a sufficient distance up to the box wall.

In a non-Illustrated embodiment of the invention, the hand tool is capable of swivelling parallel to the base plate and at right angles to the longitudinal axis in a crank guide, not about a fixed axis, relative to the base plate.

8

Claims

1. Motor-driven hand tool (10), in particular a jig saw, having a longitudinal axis X-X extending in forward feed direction and having a housing (11, 12), which is disposed in an adjustable, in particular hinged manner on a base plate (26) directed parallel to the longitudinal axis X-X and out of which an elongate tool (15) passes, in particular a reciprocating saw blade, which is directed at right angles to the longitudinal axis X-X as well as towards the base plate (26), characterized Mi that the tool (15) jointly with the housing (11, 12) is supported so as to be capable of swivelling relative to the base plate (26) about an axis Y-Y, which is aligned substantially at right angles to the longitudinal axis X-X and parallel to the base plate (26).

2. Hand tool according to claim 1, characterized in that the housing (11, 12) is disposed on a carrier (17), which is supported so as to be capable of swivelling relative to the base plate (26) about the axis Y-Y.

3. Hand tool according to claim 1, characterized in that the carrier (17) is supported on a guide element (20) so as to be capable of swivelling relative to the latter about the axis Y-Y and that the guide element (20) is fastened releasably to the base plate (26).

4. Hand tool according to claim 3, characterized in that the guide element (20) has a fork-shaped cross section and comprises a middle part (25), which is parallel to the base plate (26), in particular connectable to the base plate (26), and is adjoined on either side by a guide part (27, 28) bent symmetrically through 45', so that the guide parts (27, 28) are inclined by 90' relative to one another.

9

5. Hand tool according to claim 4, characterized in that the guide parts (27, 28) verge in each case into a bearing part (29, 30), which is disposed symmetrically relative to the other bearing part and is used for pivotally receiving the carrier (17).

6. Hand tool according to at least one of the previous claims, characterized 'm that two stops (21, 22) are provided on the guide element (20) for delimiting the swivelling range, in particular for arresting the swivelling position, of the carrier (17).

7. Hand tool according to claim 6, characterized m that the carrier (17) positioned parallel to the middle part (25) of the guide element (20) is arrestable against the stop (2 1).

8. Hand tool according to claim 7, characterized in that the stop (2 1) is disposed on the middle part (25) of the guide element (20) so as to be rotatable about an axis (23) extending at right angles to the latter and is designed as an eccentric in the region of its retaining faces, in particular a retaining piece (23), associated with the carrier ( 17).

9. Hand tool according to claim 8, characterized in that the stop (2 1) is provided with a locking key (24) and a retaining piece (23).

10. Hand tool according to claim 9, characterized in that the axis Y-Y is 25 disposed between the base plate (26) and the longitudinal axis X-X of the tool (15).

A motor-driven hand tool substantially as herein described with reference to the accompanying drawings.