WO1987003230A1

WO1987003230A1 - Arrangement for a shield to be placed over a working area to lighten the moving of the shield and to lock it into a shielding position

Info

Publication number: WO1987003230A1
Application number: PCT/FI1986/000136
Authority: WO
Inventors: Erkki Antero Jaatinen
Original assignee: Individual
Current assignee: Individual
Priority date: 1985-11-26
Filing date: 1986-11-26
Publication date: 1987-06-04
Anticipated expiration: 1988-05-26
Also published as: FI854665A0; SE8702949D0; FI77317C; FI77317B; SE457437B; SE8702949L; FI854665L

Abstract

Arrangement for a shield (4) turnable advantageously over a working area for chip-forming machine tools to lighten the moving of the shield (4) and advantageously to lock it into shielding position. Shield according to the invention is characterized in that it includes a turning mechanism (1), advantageously a jointed lever means (13, 14), which connect the shield (4) with a fastening part (2) and/or carrying part (51; 61); and advantageously at least one power means (8, 9) influencing the turning mechanism (1), advantageously telescopically moving pressure spring.

Description

Arrangement for a shield to be placed over a working area to lighten the moving of the shield and to lock it into a shielding position

"*^■ The present invention relates to improvement of work safety and _g particularly to an arrangement for a shield to be advantageously .

* placed over a working area foe chip-forming machine tools, as lathes, cutters, drilling and grinding machines and similar to protect the operator both against flying chips and rotating machine parts.

10

The most common accidents when machine tools are used are eye dama¬ ges and therefore it has been a tendency to use to growing extent protective devices for individual machines, by which flying of chips detached from the workpiece outside the machine tool has

.,- been tried to prevent. A substantial potential danger factor is also formed by the rotating bed portion, to which the workpiece is fastened, or the rotating working blade.

Before-known protective devices can in principle be divided into 2O horizontally and/or vertically settable shields.

Horizontally settable shields are mainly used in lathes and si¬ milar machine tools as a so-called chip shield, in which case the shield can be moved along a horizontal supporting rail.

25 Examples of shields of this art are the chip shields described e.g. in the Patent Application FI-820252 and Patent Scriptures FI-65934 and GB-1558513. One of their manor disadvantages is that the security of the machine tool operator cannot be guaran¬ teed, if the workable piece extends outside the chip shield,

30 which is almost always the case when a long piece is being worked- Because the shields are also rather heavy to move around, they are often left away in practice and are therefore inefficient, which naturally is not preferable considering safe working condi¬ tions.

35

Vertically and horizontally settable shields are mostly used in machine tools as cutters and grinding machines, whereby a cover¬ ing shield has been attached to the end of a supporting arm ro- tatably axled at its lower end near the machine tool. Examples of this kind of a shield include e.g. the shields described in the Patent Scriptures US-596762 and GB-15731 6. A disadvantage in these shields is that positioning of the actual shield from one selected orientation to another is cumbersome and heavy and due to the inconvenient transferability thereof the shield is often excluded in use, which naturally is not preferable con¬ sidering safe working conditions.

The object of the present invention is to eliminate such disad¬ vantages and weaknesses characteristic to previously known shields and to provide an improvement for settable machine tool shields, which above all would facilitate and lighten the trans¬ fer of the shield and would enable both rapid locking and swiftly releasable interlock of the shield enhancing thus sig¬ nificantly the probability that the shield would also be used in practice.

This object has been achieved by the arrangement mentioned above intended to lighten the transfer of a settable machine tool shield and to lock the shield into a shielding position. Characteris- tical features of the arrangement according to the invention have been disclosed in the appended claims.

One of the advan.tages of the invention is that the shield can be set and locked to the desired shielding position without any keys or other auxiliary equipment, so that the machine tool operator should only give the right direction for the shield upon its transfer. In this case the lightness in use, simple structure and easy operation of a machine tool shield provided with the arrange¬ ment according to the invention give the best guarantee, that this protective device would also be used when the machine tool is operating.

The invention will be described in the following by way of examp¬ le by some of its preferable embodiments with reference to accom¬ panying drawings, in which: FIG. 1 shows as a perspective view a milling machine shield equipped with the arrangement according to the invention to lock the shield and to lighten its transfer; FIG. 2 shows as perspective view a lathe shield provided with the arrangement according to the invention to facilitate the turn¬ ing of the shield and the locking thereof to the shielding posi¬ tion;

FIGS 3 and 4 show as partly sectioned side views the bed shield belonging to the lathe shield according to FIG. 2; and FIG. 5 shows as a cross-sectional side view the chip shield be¬ longing to the lathe shield of FIG. 2.

The shield shown in FIG. 1 is specially intended for cutters. The shield 4 to be transferred to cover a working area is most advantageously composed of a bent metal sheet with about 2 mm thickness including window apertures with about 5 mm security glass to facilitate the observation of the working procedure. The shield 4 has been suspended at the end of an intermediate shaft 1 comprising the first shaft portion 13 and the second shaft portion 14 jointed as turnable relative to each^'other. This joint between the shaft portions 13 and 14 has been pro¬ vided with a tightening means e.g. a winged nut, so that the joint can be tightened as immobile. Because of- the lockable shaft portions 13 and 14 the shield can be fitted rapidly and conveniently on the one hand to machine tools with different dimensions and on the other hand the fitting of the shield can fundamentally be facilitated both for frequently repeated simi¬ lar and often varying work phases.

The other end of the intermediate shaft 1 can be fixed to the frame of the machine tool by a fastener, part 2, preferably comp¬ rising two segments, in which case the segments formed as e.g. a U-piece have been axled as rotatable in relation to each ot¬ her. The first shaft portion 13 composed of a metal element tapering towards its end away from the fastener part 2 and bent as a U-profile is fixed at its side walls for instance by spindle joints turning like a lever to the lugs of the upper

U-piece. Thus the intermediate shaft 1 can both be turned about

180° and rotated about 360° in relation to the surface of the fastening object.

The second shaft portion 14 of the intermediate shaft 1 compri¬ ses three bar elements connected by welding to each other and forming an assembly resembling a three-branched letter Y. One branch O_'f this assembly has been jointed to the free, i.e. away from the fastener part 2 turned, end of the first shaft portion, so that the loint in question can be tightened as immobile. One branch of the remaining two of the three-branched assembly has been connected by a spacer 3 to the shield 4 that can be moved over the actual working area and the other branch is formed as a handle facilitating the moving of the shield 4 and acting moreover as a fastening support of the facilities according to the invention lightening the moving of the shield 4.

As shown in FIG. 1 the shield 4 is connected to the second shaft portion 14 by a. spacer 3. Then a ball-headed projection 15 has been placed to the edge of the shield 4 and the spacer comprises two halves 16 and 17 between the base surfaces of which has been formed recessions corresponding both the end of the second shaft portion 14 and the projection 15- The spacer 3 has also been pro¬ vided with a locking means 10, as a tightener screw, winged nut etc., to tighten the halves around the end of the second shaft portion 14 and the projection 15. By this tightener screw the shield 4 can, if desired, be locked as immobile in regard to the second shaft portion 14. when the tightening means has been loosened the shield can be turned completely freely on the spa- cer 3. In this way positioning of the shield 4 for all kinds of wor .phases can be effected quickly and easily, which naturally increases voluntary use of this safety means.

In order that positioning of the shield 4 and its staying over the working area could be assured and that the moving of the shield 4 could be as light as possible the safety means accord¬ ing to the invention is provided with lightening means for locking and moving the shield. In the embodiment according to the FIG. 1 these means include two telescopically moving power apparatus 8 and 9, e.g. pressure springs, which are commercially available from._several equipment manufacturers. Pressure springs 8 and 9 have been fitted successively in the embodiment accord¬ ing to FIG. 1 between the fastener part 2 and the first shaft portion 13. In the embodiment shown in FIG. 1 the free end of the pressure spring 8 has been axled to the spindle between two U-pieces of the fastener part 2, which spindle can for this pur- pose be equipped with lugs.

To achieve a controlled movement of the pressure springs 8 and 9 a control valve 18 and means 19 to alter the operational space of the control, valve 18. and therefore to lengthen or shorten the pressure springs 8 and 9 and respectively to tilt the intermediate shaft 1 have been fitted betwe.en them.

Means 19 for altering the operational state of the control valve 18 comprise according to the preferred embodiment of the inven- tion a hand-operable handle part fastened to the branch of the shaft portion 14 and acting as a gripping handle facilitating the moving of the shield 4, and a transmission organ, e.g. a cable moving inside a mantle pipe and transmitting the movement of the handle part to the control valve 18. Then by pressing the handle part the movement of the mentioned transmission organ opens the control valve 18 and the shield 4 can be transferred to the desired position and by releasing the handle part the shield 4 is locked to its selectee position.

The shield shown in FIG. 2 is intended to be fitted to a lathe.

It comprises two independently of and complementary to each other transferable shields, of which the left-hand one functions as a bed shield 5 transferable to the bed part on a slide rail and at that point turnable over the bed part and the right-hand one as a chip shield being either transferable on the slide rail or fastened to a blade carriage and moving thus along with the blade carriage to be turned over the working area. The chip shield 6 and the bed shield 5 can thus be moved, either one or both depending on the horizontal extent of the working area, to cover the working area, so that when long pieces are being worked the chip shield 6 covers thus the.working area and the bed shield 5 protects the rotating bed part or blade of the machine tool. Considering the working safety it is advantageous that even a small lifting of the chip shield 6 or the bed shield 5 from the horizontal position stops the machine tool and that the machine will not be started before the shield in question has again been turned down to the horizontal position-

In the embodiment according to FIG. 2 both the chip shield 6 and the bed shield 5 have been according to the invention fastened to the supports thereof by a turning mechanism provided with lightening means for their movement.

The bed shield 5 shown in FIGS 3 and 4 is composed of a metal sheet with about 2 mm thickness, compressed to a decklike form. The bed shield has been fixed by a turning mechanism 7 comprising advantageously jointed levers and the guides thereof to the car¬ riage part 51 moving on a profile rail 52, which acts as a gui¬ ded slide on ball bearings, which rail 52 has been supported to a horizontal position behind the lathe. When the bed shield 5 is out of use, it is lifted to the vertical position and pushed to the left-hand end of the profile rail 52, so that it is^' comp¬ letely displaced from the lathe bed. When the bed shield 5 is taken to use, it will be transferred along the profile rail 52 to the right as far as the limiter in the profile rail 52 allows and turned then down over the bed, into which position the bed shield 5 will also be locked.

The chip shield 6 shown in FIG. 5 is composed of two elements 62 and 63 axled turnably against each other to the closed posi¬ tion, whereby the chip shield 6 stands in the ready position shown in FIG. 5 with the unbroken line, and to the opened position, whereby the chip shield is essentially in a horizontal shielding position shown in FIG. 2 by the broken line. Elements of the chip shield 6 have been made of two metal sheets with about 2 mm thick¬ ness compressed to a decklike form, one of which sheets comprises a window aperture coated by a laminated glass plate with about 5 mm thickness to facilitate the observation of the working pro¬ cedure. The chip shield 6 has been attached by a turning mechanism comprising advantageously intermediate levers 73, 74 and a spring means 8 to the supporting part 6 fixed to the blade carriage of the lathe. Thus the chip shield 6 follows the progress of the working procedure being always there, where chipping takes place. When the chipping shield 6 is out of use, it is turned to vertical position away from the blade carriage behind the lathe. When the chip shield 6 is taken to use it is drawn from its upright ready position over the blade carriage, whereby it guided by the jointed levers is set essentially to a horizontal position over the blade carriage and is locked into the mentioned horizontal position, i.e. shielding position.

The jointed levers belonging to the turning mechanism 7 of the bed shield 5 are as follows. The bed shield 5 is fixed to the carriage part 51 by supporting shaft pairs 71 and 72. Thus the first supporting shaft pair 71 has been axled at its one end turnably like a lever to the upper edge of the carriage part 51 and at its other end between the second supporting shaft pair 72. The second supporting shaft pair 72 is fixed stationary to the upper surface of the bed shield 5 and locked at its end near the profile rail 52 to the carriage part 51 by a spindle, for which the carriage part 51 has a vertical guide groove. When the bed shield 5 is turned from the upright position to the shielding position the ends of the first supporting shaft pair 71 axled to the bed shield 5 are detached as levers from the carriage part 51 , while the bed shield 5 simultaneously and gradually turns around the axling point between the first and the second support¬ ing shaft pairs. Consequently the spindle locking the ends of the second supporting shaft pair 72 near the carriage part 51 is lifted in the guide groove. When the bed shield is turned to the opposite direction or from shielding position to upright position, the spindle moves naturally in the guide groove to opposite direc¬ tion or downwards.

The turning mechanism of the chip shield 6 comprises intermediate levers 73 and 74 interconnecting the shielding elements 62 and 63 of the chip shield, the movements of which levers determine the movements of the shielding elements 62 and 63 relative to each other and thus the path of the chip shield 6 from the ready position to the shielding position and vice versa. As intermediate levers can be used e.g. a jointed pair of levers 73 and 74 shown in FIG. 4, the first end of which is fixed to the first shielding element 62 and the other end to the second shielding element 63. Instead of the jointed pair of levers it is naturally possible to use also other limiting means for the mutual movement, for instance a slide bushing in the second shielding element 63 and a guide bar in the first shielding element 62, along which bar the slide bushing travels when shielding are moved.

To lighten the moving of the chip shield 6 the turning mechanism 7" of the chip shield 6 includes at least one spring means, advantageously a telescopiσal pressure spring 8 shown in FIG. 4 and axled at its one end to the lug 75 in the supporting part 61 of the chip shield 6 and at its other end to the cantilever part 76 fixed to the shielding ele- ment 62 axled to the carrying part 61. To lock the chip shield 6 to the shielding position the cantilever part 76 has been fastened to a slanting angle, in this case about 30 , in relation to the shield¬ ing element 62, whereby the cantilever part 76 turns past the line going through the center axle of the pressure spring 8, i.e. dead point of the locking, forming the locking maintained by the pressure spring in the shielding position. When the chip shield is turned away, as desired, from the shielding position, the chip shield 6 is pushed, so that the cantilever part 76 turns past the mentioned dead point and the chip shield rises by itself under the effect of the pressure spring a. Moreover the chip shielding elements 62 and 63 have been ba¬ lanced to make the turning to the lower position as light as possible so that it would happen almost by the dead load of the shield 6. The invention has been described above only by some of its advantageou embodiments. This does not, of course, limit the invention as being valid only for this kind of individual embodiments, but various modifi cations and assemblies are possible within the scope of the appended claims.

Claims

1. Arrangement for a shield turnable advantageously over a working area fo chip-forming machine tools to lighten the moving of the shield (4;5;6) and advantageously to lock it into shielding position, characterized in that the arrangement includes a turning mechanism (l;7;7), advantageously a jointed lever means, which connect the shield with a fastening part (2) and/or carrying part (51;61); and advantageously atleast one power means (8,9) influencing the turning mechanism (1;7;7), advantageously teles- copically movable pressure spring.

2. Arrangement for a shield according to claim 1, which is carried by an intermediate, advantageously jointed, shaft (1) supported by a fastening part (2) to a substrate, characterized in that the arrangement includes tw successively fitted pressure springs (8,9), which are axled between the fastening part (2) and the jointed intermediate shaft (1) carrying the jointed shield, and atleast one operational device controlling the movemen of the pressure springs (8,9).

I

3. Arrangement according to claim 2, characterized in that the operational device contolling the movement of the pressure springs includes a control valve (18), which is fitted between the pressure springs (8,9), and means (19) for altering the operational state of the control valve (18) and thus for locking or releasing the shield (4).

4. Arrangement according to claim 3, characterized in that means (19) for altering the state of the control valve includes a hand-operated handle part fastened to a second shaft portion (14) of the jointed intermediate shaft, both a transmission organ between the control valve and said handle part, whereby by pressing said handle part said transmission organ opens the control valve (18) and the shield (4) can be moved, and whereby by releasing said handle part the shield is locked as immobile.

5. Arrangement for a two-part bendable shield (6) which shield is fastened turnably to its carrying part (61), characterized in that the arrangement includes; at least one means, advantageously pair of jointed intermediate shafts, for defining the motion orbit of the bendable shield elements (62, 63) of the shield (6); and means (8,75,76), advantageously atleast one telescopically movable pressure spring (8) , to lighten the moving of the shield and to lock it into shielding position.

6. Arrangement according to claim 5, characterized in that the pressure ^' spring (8) is axled at its one end to the carrying part (61), advanta¬ geously to a lug (75) stationary fixed to it, and at its second end to a shield element (62), advantageously to a cantilever part in it.

7. Arrangement according to claim 6, characterized in that the cantilever 0 part is stationary fixed to a such angle that upon turning the shield (6) into the shielding position the cantilever part (76) turns past the dead point of locking, whereby it is formed locking maintained by the pressure spring (8) , which can be released by turning the cantilever part, advan¬ tageously by pushing the shield (6), past said dead point, whereby the 5 shield (6) turns away from the working area by means of the pressure spri (8).

8. Arrangement according to claim 7, characterized in that the angle between the shield element (62) and the cantilever part (76) is permanent 0 and oblique, advantageously about 30°..

9. Arrangement according to claim 1 for a lathe shield composed of a chip shield (6) and a bed shield (5) which lathe shield alteast the chip shiel is composed of bendable axled shield elements (62,63) and in which lathe

25 shield both said chip shield and bed shield are axled turnably both to it own carrying part (51,61), characterized in that the arrangement includes atleast one means, advantageously jointed pair of intermediate shaft (73,74) for defining the motion orbit of each shield element (62,63) of t bendable shield; and means (8,75,76) , advantageously atleast one teles-

30 copically moveable pressure spring (8) to lighten the moving of the shiel and to lock it into shielding position.

10. Arrangement for a shield (4,5,6) turnable advantageously over a worki area, for a chip-forming machine tool to lighten the moving of the shield

35 and advantageously to lock it into a shielding position, characterized in that the arrangement is essentially the like as descriped in the accom¬ panying patent description, in the accompanying patent claims 1...9 and/o in the appended patent drawings.