Device for rotating an emitter device emitting a laser beam for the purpose of generating a plane or a conical surface

A device for rotating an emitter device emitting a laser beam L about a rotation axis for the purpose of generating a plane or a conical surface has an elongated body of revolution 2 which carries the emitter device 1 and is held rotatably at the ends on a fixed holder 5 by means of a pivot bearing 3, 4 in each case, the pivot bearing 3, 4 comprising a conical seat 16 and a bearing member 17 engaging in the latter and having a rounded outer surface concentric with the rotation axis, and the conical seat 16 and the bearing member 17 being prestressed (20) against one another.

BACKGROUND OF THE INVENTION 
The invention relates to a device in accordance with device for rotating an 
emitter device. 
BRIEF SUMMARY OF THE INVENTION 
It is the object of the invention to create a device for rotating an 
emitter device by means of which it is possible to achieve on a length of 
10 m a very small maximum laser beam deviation of the order of magnitude 
of, for example, 10 to 50 .mu.m from a prescribed spatially fixed 
reference beam, and which nevertheless is distinguished by very high 
flexural and torsional strengths of their structural elements, and by a 
high insensitivity and resistance to stresses, in particular shocks, 
during manipulation, with the result that it is possible to use it to 
measure, in particular, flat surfaces such as, for example, machine beds, 
machine erection frames and more with a very high accuracy even under 
rough operating conditions. 
For the purpose of mounting structural elements in a highly precise 
rotatable fashion with respect to one another, it is known to use 
precision ball bearings, or to mount the elements, for example easily 
running precision parts of clocks, between pivots. 
The target accuracy for the device according to the invention cannot be 
achieved using precision ball bearings, and the known pivoting bearing has 
the disadvantage that it is very susceptible to shocks and not robust 
enough, thus it is very high sensitivity to transportation. 
The above named object of the invention is achieved by a device for 
rotating an emitter device emitting a laser beam about a rotation axis, 
enclosing a presettable angle with the laser beam for the purpose of 
generating a plane or a conical surface, wherein the emitter device is 
fastened to an elongated solid body of revolution which, with its ends, is 
mounted by means of a pivot bearing in each case on a holder which can be 
fixed in space, such that it can rotate about a longitudinal axis of the 
body forming the rotation axis, and wherein each pivot bearing comprises a 
conical seat, concentric with the rotation axis on the body of revolution 
or on the holder, and a bearing member fastened to the holder or to the 
body of revolution having a rounded outer surface which is concentric with 
the rotation axis and engages the conical seat, and a bearing member being 
prestressed against one another in a direction of the rotation axis in the 
case of each pivot bearing. 
The invention is based on the finding that, on the one hand, rotationally 
symmetrical bearing members having a rounded outer surface, for example 
balls, can be produced, in particular can be ground, with very high 
accuracy and that, on the other hand, under prestressing such bearing 
members are more or less grounded with time into the associated conical 
seat, with the result that there is constructed between these parts a 
contact surface essentially in the form of a circular ring which increases 
the insensitivity to shocks, on the one hand, and increases the precision 
of the bearing, on the other hand. 
The present invention provides that the body of revolution be a solid rigid 
axle and the holder is designed as a solid hollow body surrounding the 
rigid axle from which the body of revolution projects with one of its ends 
and carries the emitter at the end face. The body of revolution may have 
an outer surface which is spherical. 
The present invention further provides for at least one of the two bearing 
members to be a ball, wherein the at least one ball may be inserted into a 
conical depression in the body of revolution or in the holder and is 
fastened therein. For instance, the ball may be bonded into the conical 
depression. The conical seat may be constructed on a separate seating part 
fastened to the body of revolution or to the holder. 
The present invention provides that the prestressing is provided by a 
spring which is stretched between a pivotable fork arm and the part of the 
holder connecting the fork arm. 
The present invention provides for the device to be defined by a solid 
stand which can be fixed on a holder for fixing the holder in a desired 
position in space. The present invention provides for the stand to be 
attached laterally on the outside to a rigid fork arm or to be attached at 
the end face to the end of the holder projecting from the body of 
revolution. The stand can also be attached laterally on the outside of the 
holder. 
The present invention further provides for the holder to be configured in a 
shape of a fork such that it spreads around the body of revolution at the 
end faces with its fork arms and bearing members are arranged on the ends 
of the faces of the body of revolution and the conical seat is arranged at 
the free end of the fork arms of the holder or vice versa. The two fork 
arms of the holder can be pivoted about a pivoting axis which crosses the 
rotation axis at a distance essentially at right angles, is articulated to 
the remainder of the holder, and is elastically braced against the latter 
toward the body of revolution. One of the fork arms of the holder may be 
provided with a continuous bore which also extends through the bearing 
member, adjoins the conical seat, and is coaxial with the rotational axis, 
and wherein the emitter device is attached to a carrier which is fastened 
to a bolt penetrating the bore and resiliently connected to the body of 
revolution. 
The present invention further provides for the solid, rigid axle to serve 
as a holder and the body of revolution is designed as a solid, rigid, 
hollow body which surrounds said axle, is supported at one end face 
internally on the neighboring end face of the holder by means of one pivot 
bearing, carries the emitter externally at the end face or on a 
circumferential side, and from which the holder projects with one end at 
the other end face. 
The present invention provides for one of the pivot bearings to be located 
on the circumferential side of the holder in the vicinity of the end of 
the holder projecting from the body of revolution, the rounded bearing 
member of the pivot bearing being fastened on a circumferential side to 
the holder, in a fashion surrounding the latter at a rounded ring, and the 
associated conical seat being constructed at a collar of the body of 
revolution which surrounds the holder and extends radially inward. Also, 
one pivot bearing can be arranged at the end face of the other end of the 
body of revolution, and the other pivot bearing is located on the 
circumferential side of the body of revolution in the vicinity of the end 
of the body of revolution projecting from the holder, the rounded bearing 
member being fastened on a circumferential side to the body of the 
revolution in a fashion surrounding the latter, as an externally rounded 
ring, and the conical seat being constructed at a collar of the holder 
which surrounds the body of revolution and extends radially inward. 
The present invention provides strip bearings which in each case have a 
wide middle strip which is fastened non-rotatably to the two parts to be 
connected in the strip plane in each case and two side strips which are 
arranged on both sides thereof in a neighboring fashion and are fastened 
to the two parts to be connected, in a plane which is essentially at right 
angels to the plane of the middle strip, wherein the strips consist 
essentially of material which is essentially inextendable and at least 
within limits, flexible, such as spring metal. 
The present invention further provides for an end wall being averted from 
the projecting end of the holder, the body of revolution having a seating 
part which is arranged essentially centrally, can be axially displaced 
within limits against a spring force and is held on the remaining part of 
the body of revolution via a leaf spring or the like. 
The present invention provides the emitter device being attached to the 
body of revolution at an adjustable angle.

DETAILED DESCRIPTION OF THE INVENTION 
The device in accordance with FIG. 1 serves to rotate an emitter device 1 
emitting a laser beam L (indicated diagrammatically), such that the laser 
beam L generates a plane or a conical surface depending on the setting of 
its angle with respect to the rotation axis D of the device. 
In the embodiment according to FIG. 1, the emitter device is fastened to an 
elongated solid body of revolution 2 in the form of a solid, rigid axle 
which, with its ends, is mounted by means of a pivot bearing 3 and 4, 
respectively, in each case on a holder 5 which can be fixed in space, such 
that it can rotate about its longitudinal axis forming the rotation axis 
D. Here, the body of revolution 2 preferably has a circular cross section. 
In the embodiment according to FIG. 1, the emitter 1 is fastened in a 
height-adjustable fashion to a holder 5 which comprises a slide rod 6, 
extending approximately parallel to the rotation axis D and pivotably 
connected at its lower end to the body of revolution 2, a sliding piece 7, 
slidably attached to said slide rod, capable of having its height level 
fixed and carrying the emitter device 1, a helical tension spring 9, 
fastened at one end to the slide rod via a bow 8 and at the other end to 
the body of revolution, and a micrometer screw 10 which can be adjusted 
with respect to the slide rod 6 at right angles to the longitudinal axis 
thereof and via which the slide rod 6 is supported against the body of 
revolution 2. The angle between the longitudinal axis of the slide rod 6 
and the rotation axis D can be set and varied precisely by adjusting the 
micrometer screw 10 with respect to the slide rod 6. 
The articulated connection between the slide rod 6 and the body of 
revolution 2 at the lower end of the slide rod 6 is provided by a strip 
bearing which has a middle, relatively wide strip 11, which by means of 
fastening blocks 12 and 13 is fastened nonrotatably to the two parts 2, 6 
to be connected, in the strip plane in each case and two side strips 14, 
15, which are arranged on both sides of the strip 11 in a fashion adjacent 
to the latter and are permanently attached to the fastening blocks 12 and 
13 at right angles to the middle strip 11. The strips 11, 14 and 15 
consist of essentially inextensible, and, at least within limits, flexible 
material, preferably spring metal. A perspective view of such a strip 
bearing is shown in FIG. 7. 
In the device according to FIG. 1, the pivot bearings 3, 4 are designed to 
be mutually identical, each pivot bearing 3 or 4 comprising a conical seat 
16, concentric with the rotation axis D, in the respective end face of the 
body of revolution 2, and a bearing member 17, fastened to the holder 5, 
having a rounded outer surface which is concentric with the rotation axis 
D and engages in the seat 16. 
In the embodiment according to FIG. 1, the bearing member 17 is in each 
case a ball which is inserted, preferably bonded, in a conical depression 
18 in the holder 5. The conical seats 16 in the end faces of the body of 
revolution 2 are constructed in each case on a separate seating part 19 
which is let into the body of revolution 2 and fastened therein. 
In the embodiment according to FIG. 1, the holder 5 is configured in the 
shape of a fork such that it is spread around the body of revolution 2 at 
the end faces with its fork arms 5a, 5b, the conical depressions 18 in 
which the spherical bearing members 17 are bonded being located at the 
free ends of the fork arms 5a, 5b. Here, the body of revolution 2 is a 
solid, rigid axle which is mounted between the free ends of the fork arms 
5a, 5b of the holder 5 in a fashion such that it can rotate about the 
longitudinal axis D of the latter. 
In order to achieve the prestressing of the bearing members 17, bonded in 
the conical depressions 18 in the fork arms 5a, 5b, and the conical seats 
16 in the end faces of the body of revolution 2 with respect to one 
another, the fork arm 5a of the holder 5 which is the upper one in FIG. 1 
is pivoted to the remainder of the holder 5 such that it can pivot about a 
pivoting axis SA, which crosses the rotation axis D at a distance 
essentially at right angles, and said arm is elastically braced against 
said holder toward the body of revolution 2 by means of a spring 20. The 
fork-shaped holder 5 is fastened to a solid stand 21 by means of which it 
can be fixed in space in a desired, more or less vertical position. 
The emitter device 1 can be rotated by applying a force using a motor 22 
which is fastened to the fork-shaped holder 5 by a motor shaft 23, which 
is essentially parallel to the rotation axis D, and can make use of a belt 
or the like 24, which is wrapped around the body of revolution 2 and a 
pinion at the end of the motor shaft 23, to pivot or continuously rotate 
the body of revolution 2 about its rotation axis D over a desired angle of 
rotation. 
Fastened to the body of revolution 2 on the side averted from the emitter 
with its holder, is a counterweight 40 which balances the mass of the 
emitter 1 and its holder. 
FIG. 2 shows a modification of the bearing, which can be used instead of 
the upper pivot bearing described in connection with FIG. 1 for the 
purpose of rotatably holding the body of revolution 2. In the case of the 
pivot bearing according to FIG. 2, a bearing member 25 provided with a 
shaft and having the rounded outer surface is fastened in a bore on the 
outer end of the fork arm 5a. The rounded outer surface 25a of the bearing 
member 25 facing the body of revolution 2 is rotationally symmetric with 
respect to the rotation axis D of the body of revolution 2 and, as in the 
case of the embodiment according to FIG. 1, engages in a conical seat 16 
in the end face of the body of revolution 2. The bearing member 25 has a 
continuous bore 27, which is essentially parallel to the rotation axis D 
and through which there extends, with sufficient play for free rotation, a 
bolt 28 which is screwed in a rotationally fixed fashion coaxially with 
the rotation axis D into the body of revolution 2. A disk-shaped carrier 
29 for the emitter 1 is fastened to the free end of the bolt 28. The 
advantage of this design of the pivot bearing and of emitter holder 
consists in that the laser beam L can be rotated by 360.degree. without 
falling on any elements of the device in the process. 
FIG. 3 shows a further modification of the pivot bearing by comparison with 
that previously described in connection with FIG. 1. In the case of this 
embodiment, in a fashion similar to the embodiment in accordance with FIG. 
2, the bearing member 30 has a shaft 31 and is bonded with the latter in a 
bore at the free end of the fork arm 5a and/or 5b such that its line of 
rotational symmetry coincides with the rotation axis D of the body of 
revolution 2. It is clearly to be seen that although the outer surface of 
the bearing member 30 is likewise rounded here, as well, it deviates from 
the spherical shape as was described at the beginning for the bearing 
members 17 in the case of FIG. 1. Such shapes can also be produced with 
high precision. 
As in the case of FIG. 1, in the embodiment according to FIG. 3 the bearing 
member 30 also engages under prestress in a depression, denoted by 32, in 
the end face of the body of revolution 2, although that depression is not 
exactly conical here, but has a configuration which is slightly concavely 
rounded. 
The embodiment according to FIG. 3 has the advantage that there is quickly 
ground in between the depression 32 and the bearing member 30 a contact 
surface which is wider than in the case of the ball and cone configuration 
in accordance with FIG. 1. The term "conical" is as well to be understood 
to include such designs of the seat. 
FIGS. 4 and 5 show a further embodiment of the device. Said embodiment 
differs from that in accordance with FIG. 1 in that a solid, rigid axle 
serves as holder 5', and the body of revolution 2' is designed as a solid, 
rigid hollow body which surrounds said axle and carries the emitter 1' 
outside on its upper end face by means of a holder 5a' extending 
essentially parallel to the end face. At the other end face of the body of 
revolution 2', the holder 5' projects from the body of revolution 2', 
there being fastened to its end face there a solid stand 21' by means of 
which the device in accordance with FIG. 4 can be set up in a stable 
fashion on a support. 
Located at the end face at the upper end of the holder 5' is a pivot 
bearing 3' which essentially corresponds to the pivot bearing 3 in the 
embodiment according to FIG. 1. What differs is that the seat element 19' 
in the body of revolution 2' can be moved against spring force in the 
direction of the rotation axis D and is held resiliently against the 
remainder of the body of revolution 2' via a leaf spring 38 or the like. 
The other pivot bearing 4' is located on the circumferential side of the 
holder 5' in the vicinity of the end of the holder 5' projecting from the 
body of revolution 2', the rounded bearing member 35 being fastened to the 
holder 5' in a fashion surrounding the latter, and the conical seat 36 
being constructed at a collar 37, which surrounds the holder 5', extends 
radially inwards and is fastened to the body of revolution 2'. 
The embodiment in accordance with FIGS. 4 and 5 permits the laser beam to 
be used to generate over an angle of rotation of 360.degree. a plane which 
extends essentially parallel with the support of the stand 21' or a 
conical surface whose central axis is at right angles to said support. 
Bearing members which have the shape of the bearing member 35 of the 
embodiment in accordance with FIG. 4 and are configured as an externally 
rounded ring can also be produced with the highest precision. 
FIG. 6 shows a third embodiment of the device, which essentially differs 
from that in accordance with FIGS. 4 and 5 in that the outer body 
configured as a hollow body forms the holder 5", while the solid, inner 
body serves as the body of revolution 2', the solid stand 21' being 
fastened to the external circumference of the body of revolution 2', the 
emitter 1" being permanently attached to the end face of the body of 
revolution 2', and the device being held by the stand 21 such that the 
rotation axis D extends parallel or somewhat obliquely to the support on 
which the stand 21" stands. 
Planes or conical surfaces which project upward from the support of the 
stand 21 can be generated using the device according to FIG. 6. 
It is also possible in the case of the embodiments in accordance with FIG. 
4 and FIG. 6 for the emitter to be fastened to the body of revolution 2' 
such that its angle can be adjusted within limits. This should preferably 
be performed using a pivot bearing 5 of the type employed in the case of 
the embodiment in accordance with FIG. 1.