LASER BEAM DISPLAY DEVICE FOR ALIGNING TWO POINTS SPACED APART FROM EACH OTHER

Abstract: A laser beam display device (1) for aligning two points spaced apart from each other. In such a device a laser tube (7) is disposed inside a metal tubular supporting element (6) and in engagement therewith, spring rings (19, 20) being suitably interposed between the laser tube (7) and the tubular body (6) and closely adhering to the inner wall of the latter. Inside the tubular body (6) and at the ends thereof, provision is also made for some soft silicon-based separation material. What above is all contained, together with operating devices for the laser tube (7) and with an axially-centering device (9) for the issuing laser beam, within a hull (2) closed at the top by a cover (3) provided with a portion (4) susceptible of overturning and secured at its free end to the hull (2) itself in a removable manner.

Description: "Laser beam display device for aligning two points spaced apart from each other" The present invention relates to a laser beam display device for aligning two points spaced apar't from each other, of the kind comprising a containing box-shaped body provided at its lower part with attachment means for fastening it to an appropriate implement, a metal tubular supporting body, rigidly fixed inside said box- shaped body and housing in turn a laser tube, an optical axially-centering group disposed in coaxial relation with said laser tube in the region of the outlet capillary of the latter and input means for an electronic operating circuit for said laser tube. • •It is known that display devices of the above mentioned type are becoming more and more used in many technical fields. In fact, i ' t is known that one of the main features of a laser tube is to emit a light beam having a very reduced taper and susceptible of further reduction by virtue of the axially-centering member with which said laser beam display devices are provided. In this way, practically a very strong light ray comes out of the display device which interferes, at some distance, with the point with which it is wished to achieve or verify the linearity with respect to the starting point of the laser tube. Owing to the fact that in many cases an alignment system by means of a light ray is undoubtedly more practical and precise than other known systems adapted to achieve the alignment between two points, in recent years alignment devices based on the light beam emitted by a laser tube are having more and more success. In order to give some examples of the great number of technological fields in which such devices' are applied, it is sufficient to mention road building, tunnel boring, cutting machine tools; furthermore they are used instead of the traditional guide templates when vehicle bodies have to be repaired and in the firearm field instead of the traditional sighting systems, and so forth. A known display device of the universal type, that is susceptible of being indifferently applied to equipments of every sort, substantially comprises a metal tubular envelope inside which a laser tube is elastically housed which aesthetically is in the form of a glass tube terminating at one end in an outlet capillary. In the region of said capillary and in coaxial relation with the metal tubular body containing the laser tube, is mounted an optical device for adjusting the light beam emitted by the laser tube. Such a device is substantial¬ ly composed of a sleeve adapted to be screwed in said end of the tubular body and a pair of lenses are. disposed inside it; said lenses, suitably displaced by an' appropriate adjusting means, allow the focus of the optical system to be brought to the desired point. Said tubular envelope and adjusting device are then mounted on a box-shaped support body which is arranged s o that it can contain the electrical supply means for the laser tube conventionally consisting of an electronic circuit, a transformer for the high tension supply and a storage battery. In turn said box-shaped body is provided with means for fastening the whole device to the equipment or implement that must carry out a particular function or work, in a strictly rectilinear manner. Such a means substantially consists of a bar having a trapezoidal cross section and provided with a number of through holes disposed in axial alignment with and at a predetermined and constant distance from each other. Through said holes the bar can be fastened, by means of screws, to the lower side of the tubular body. In this way the bar can be inserted into grooves countershaped to the same and provided on a pair of jaw-like supports adapted to be clamped on the equipment or implement in question. In known devices of the above mentioned type however it was possible to find out some drawbacks above all due to the great number of technical problems that have to be simultaneously solved. One of these problems is caused by the housing conditions of the laser tube inside its containing envelope. First of all it is necessary to bear in mind that such a housing must be elastic so that undesired and some¬ times inevitable impacts may not cause the breaking of the glass tube or of the capillary. At the present time such elastic housing is achieved by injecting some silicones or a spongy material between the metal tubular body and the laser tube. However if the injected silicon-based material is too much, the protective sheath thus formed would become too stiff and a possible impact would break the glass tube. On the contrary if the silicon amount is not sufficient, although the protective sheath would succeed in taking up the impact, it would not be atjle to effectively damp the vibrations induced by the impact itself. As a result the breaking of the capillary of the laser tube would be possible. Finally, on the other hand, should the injected material be too spongy, a possible impact and the subsequent vibrations would be easily taken up, but the protective sheath would not be elastic enough to bring the laser tube perfectly back to its initial position and as a result the beam of light emitted would become misaligned ' . A further problem relative to the known laser beam display devices resides in the difficulty of housing the whole electrical supply equipment for the laser in a box- shaped body that for some particular applications must be as small as possible. Due to the necessity of a very reduced bulkiness, hen the batteries must be changed some parts of the box-shaped body have to be disassembled, which might cause the loss of some pieces or screws above all if the replacement takes place under unfavourable conditions or in unsuitable places.. A still further drawback relative to the above described known devices concerns the means designed for fastening such devices to some types of equipments. In fact,in some cases the equipment on which the laser beam display device is mounted transmits some longitudinally-directed rebounds to the same, which rebounds are taken up by the screws fastening the bar to the box-shaped body. By effect of these rebounds the screws may break or undergo permanent deformations leading to a misalignment of the laser with respect to the equipment on which it is mounted. The main object of the present invention is to eliminate the above mentioned drawbacks and to provide a laser beam display device for aligning two points spaced apart from each other which is capable of taking up the effects of impacts, vibrations and rebounds to which the device can be submitted without damaging the laser tube and without causing the misalignment thereof. A further object of the present invention is to make available a laser beam display device structured in such a manner that it has a very reduced bulkiness and that it allows an easy replacement of the batteries without the risk of losing screws or other elements. The foregoing and still further objects that will become more apparent from the following description, .are attain- ed, according to the present invention, by a laser beam display device (1) for aligning two points spaced apart from each other of the kind comprising a containing box- shaped body provided at its lower part with attachment means for fastening it to an appropriate implement, a metal tubular supporting body (6) rigidly fixed inside said box-shaped body and housing in turn a laser tube (7), an optical axially-centering group (9) disposed in co- axial relation with said laser tube (7) in the region of the outlet capillary (8) of the latter and input means for an electronic operating circuit for said laser tube (7), characterized in that it comprises an inwardly-cradle-shaped base hull (2) closed at the top by a cover (3) consisting of a fi r xed front portion (27) and a rear portion (4) susceptible of overturning with respect to the front one (27) by means of a hinged articulation (5), fastening means for fixing said rear portion (4) to the hull (2), disposed at the end of said rear portion (4) opposite the hinged articulation (5), a pair of half-moon-shaped elements (13, 14) located inside said tubular body (6) close to the ends thereof and provided with respective threaded through holes for securing said tubular body (6) to the bottom of the hull (2), two pairs of spring rings (19, 20) mounted around said laser tube in close contact with the metal tubular supporting body (6) and located in the central portion and at the ends of said laser tube (7) respectively. Further features and advantages of the invention will become more apparent from the detailed description of a preferred embodiment of a laser beam display device given hereinafter by way of example only with reference to the accompanying drawings in which: - Fig. 1 is a broken away perspective view of the device according to the invention; - Fig. 2 is a cross-sectional view of the metal tubular body housing the laser tube provided with means for fastening it to the box-shaped body; - Fig. 3 is a cross sectional view of the device taken from the screw fastening the rear portion of the cover to t he hul l Referring to the drawings and particularly to Fig. 1, it has been generally indicated at 1 a laser beam display device for aligning two points spaced apart from each other according to the present invention. In its essential features, such a device comprises a base hull 2 closed on top by a cover generally identified at 3. Seen transversely, said hull 2 is in the form of a cradle while the cover 3 consists of a fixed front portion 27 and of a rear portionT- 4 connected at 5, by a hinged articulation, to the fr nt portion and susceptible of being overturned with- respect to the latter for 90°. A tubular body 6 within which a laser tube 7 is located, is housed -iαside the hull 2 in a way to be described later. Conventionally, the laser tube 7 looks outwardly li-ke a glass tube terminating, at the outlet of the laser beam, in a capillary 8 also made of glass. Inside the hull 2, in coaxial relation with the tubular body 6, is located an optical axially-centering group 9 provided with corresponding adjusting means not shown. The optical axially-centering group 9 is not described in more detail as it is not the subject of the present invention. Always referring to Fig. 1, two sections adapted to be secured by means of screws to the inner upper portion of hull 2 have been indicated at 10 and 11; they are designed for supporting the electrical supply means for the laser tube 7 and for housing a seal 12 suitable to avoid entering of water or dust between cover 3 and hull 2. The electric¬ al supply means for the laser tube 7 has not been shown in the figures because it conventionally consists of a transformer, an electronic operating circuit and a storage battery. Referring also to Fig. 2, inside the tubular body 6 hous¬ ing the laser tube 7 two half-moon-shaped members 13 and 14 are located, at the ends thereof. The curved portion of said members has the same diameter as the inner diameter of the tubular body 6. Furthermore, each of said members 13 and 14 is provided with a respective threaded through hole 15 and 16. Fastening screws identified at 17 and 18 respectively are screwed down in said threaded holes after passing across corresponding through holes worked in the bottom of hull 2. Always referring to Fig. 2, 19 and 20 designate two pairs of sealing rings mounted symmetrically on the laser tube 7, and exactly i n the middle and at the ends of the laser tube itself. The spring rings 19 and 20 are mounted in such a way that they closely adhere to the inner wall of the tubular body 6 so that they elastically separate the laser tube 7 from its container 6, thus avoiding possible impacts. Furthermore, it should be noted that, advantageously, soft silicon-based material is injected into the hollow spaces of the ends defined by the spring rings 20, by the ends of the laser tube 7, and by the ends of the tubular body 6 in order to increase the effectiveness of the separation between the laser tube 7 and the tubular body 6. Turning back to Fig. 1, the cover 3 is provided, at the front portion 27 and at the rear portion 4 thereof, with projecting edges 21 and 22 adapted to be inserted-, in a closely adhering relation, into the inner portion of the upper edge of hull 2. In this way, when cover 3 is put upon hull 2, the tubular body substantially takes the form of a parallelepiped. It should be understood that when particular applications are concerned it might be necessary to execute longitudin¬ al chamfering 23 and 24 on the lower edges of hull 2. Advantageously such cha ferings should be provided with an angular inclination o f 39° with respect to the horizontal base plane 25 of hull 2. The front portion 27 of cover 3 is fixed by means of fastening screws 26 to the hull 2, while the rear portion 4, as previously specified, can be overturned through at least 90° with respect to the front portion 27. The rear portion 4, in turn, during the normal operation of the device, is destined to be fixed to the hull 2 by fastening means disposed at the ' end thereof opposite the one provided with the hinged articulation 5. Also referring to Fig. 3, such fastening means comprises a screw, generally identified at 28; the free end of the shank 29 of said screw'is provided with a threaded portion 30 having a bigger diameter than the shank 29 itself. In addition, said fastening means comprises a first threaded hole 31 worked in the rear portion 4 of cover 3 and a second threaded hole 32 worked in the middle of a strip 33 rigidly mounted on the inner part of hull 2 by means of fastening screws 34. Therefore the screw 28 is first screwed down in the hole 31 of cover 3 and subsequently in the threaded hole 32 of strip 33. In this way, when the screw 2 ' 8 is screwed out of the hole 32 in order to allow the rear portion 4 of cover 3 to be overturned for the purpose of replacing the batteries, the screw 28 cannot be lost; in fact, it cannot be detached from cover 3 unless the previous disengagement of the same, by unscrewing, from the threaded hole 31 of the rear portion 4. Always referring to Fig. 1 and according to a further feature of the present invention, the attachment means designed for securing the device in question to a given equipment comprises two blocks 35 and 36 disposed on the bottom of hull 2 and preferably of one piece construction therewith. Such blocks project outwardly and are disposed at a " predetermined distance from each other. Each of said blocks 35 and 36 is provided with a central transverse groove, identified at 37 and 38 respectively, engageable with two corresponding countershaped elements carried by the implement on which the device i.s mounted or by an intermediate hooking means. Each of said blocks 35 and 36 further comprises a pair of threaded holes, not shown in the figure, into which further fastening screws, n-ot shown, are introduced. The above described device attains the intended purposes. In fact, owing to the presence and particular arrangement of the sealing rings, which are preferably 0-rings, if the laser beam display device is submitted to an impact, the laser tube 7 can softly oscillate inside the tubular body 6 and there is no risk of breaking the glass tube, as a consequence of the impact itself, or of breaking the capillary, as a consequence of the subsequent vibrations. Beside this advantage of primary importance, there are other advantages of less consequence such as the great facility in opening the cover 3 when the battery has to be replaced, such opening manner also avoiding the lost of the fastening screws, as well as the way adopted for locking the whole device on the concerned equipment; in fact, even in the applications involving longitudinal rebounds on the laser tube, the grooves 37 and 38 provided on the blocks 35 and 36, by their engagement with elements countershaped thereto, avoid the transmission of stresses to the fastening screws thereby ensuring a constant alignment of the whole device with respect to the equipment on which it is mounted. Obviously, many structural modifications and variations may be made to the device in question without departing from the spirit and scope of the invention itself.

Claims: C L A I S 1. A laser beam display device ( ) for aligning two points spaced apart from each other of the kind comprising a containing box-shaped body provided at its lower part with attachment means for fastening it to an appropriate implement, a metal tubular supporting body (6) rigidly fixed inside said box-shaped body and housing in turn a laser tube (7), an optical axially- centering group (9) disposed in coaxial relation with said laser tube (7) in the region of the outlet capillary (8) of the latter and input means for an electronic operating circuit for said laser tube (7), characterized in that it comprises and inwardly-cradle-shaped base hull (2) closed at the top by a cover (3) consisting of a fixed front portion (27) and a rear portion (4) suscept¬ ible of overturning with raspect to the front one (27) by means of a hinged articulation (5), fastening means for fixing said rear portion (4) to the hull (2), disposed at the end of said rear portion (4) opposite the hinged articulation (5), a pair of half-moon-shaped elements (13, 14) located inside said tubular body (6) close to the ends thereof and provided with respective threaded through holes for securing said tubular body (6) to the bottom of the hull (2), two pairs of spring rings (19, 20) mounted around said laser tube (7) in close contact with the metal tubular supporting body (6) and located in the central portion and at the ends of said laser tube (7) respectively. 2. A device according to claim 1, characterized in that said hull (2) is outwardly in the form of a parallelepiped and its longitudinal lower edges are greatly chamfered. 3. A device according to claim 2 characterized in that said chamferings (23, 24) are angled at 39° with respect to the horizontal base plane (25). r ' 4. A device according to claim 1, characterized in that all the equipment for operating the device itself is sealingly housed inside the hull (2). 5. A device according to claim 1 characterized in that said fastening means for locking the rear portion (4) of cover (3) to the hull (2) comprises a screw (28) whose shank (29) exhibits a threaded portion (30) at its free end, a first threaded through hole (31) worked in said rear portion (4) of cover (3)and a second threaded hole (32) obtained in the middle of a strip (33) rigidly mounted in the inner part of hull (2), the diameter of said threaded portion (30) of the screw (28) being bigger than the diameter of the shank (29) so that the former may fixedly engage in said strip (33) after passing through the first threaded hole (31) of cover (3). 6. A device according to claim 1 characte ized in that said attachment means comprises two blocks (35, 36) of one piece construction with and outwardly projecting from the bottom of hull (2), at a predetermined distance from each other, two threaded holes being provided in each of said blocks, as well as a transverse central groove (37; 38) engageable with an element countershaped to the same, carried by the implement on which the device has to be mounted.

Inventors: PALA LUSSORIO RINALDO, PALA LUSSORIO, RINALDO
Applicants: PALA LUSSORIO RINALDO, PALA LUSSORIO, RINALDO
Application year: 1985
Main classification: H01S3
IPC codes: H01S3