| DE2907554B1 | 1980-08-21 | |||
| FR2379845A1 | 1978-09-01 | |||
| US4712851A | 1987-12-15 |
| 1. | A fixture for supporting objects in a manner to prevent shaking of said objects, e.g. for supporting objects and hologram plates when practicing holography, c h a r a c t e r i s e d b y two plates (11, 12) which are attached rigidly and permanently one to the other and of which, when the fixture is placed on a horizontal support surface, a first plate (11) will form a relatively small angle ( ) with a vertical plane, which angle, however, will be substantially different to 0° , whereas the other, or second plate (12) will form a relatively large angle (β) with a vertical plane, which angle, however, will be substantially different to 90°; and in that each of said two plates (11, 12) is provided with a multiple of holes (111, 112 121,122...) which are intended to receive respective pegs (4) for supporting abutment with an object to be supported; whereby through selection of suitable holes with respect to the shape and extension of respective objects, the object achieves possitive and safe abutment with the support pegs under the influence of gravity. |
| 2. | A fixture according to claim 1 , c h a r a c t e r i s e d i n t h a t said second plate (12) has support points for supporting said plate on a horizontal surface, said support points having the form of a hemispherical projection (21) located symmetrically on the inner end of the plate (12) close to its attachment to the first plate (11), and also the form of two symmetrically positioned legs (22) which are intended to be inserted into holes in the end of the plate distal from said inner end thereof. |
| 3. | A fixture according to claim l or 2 c h a r a c t e r i s e d i n t h a t the two multiple of holes in the plates (11, 12) are outwardly conical; and in that each of the support pegs has a corresponding conical abutment surface and a screwthreaded end for attachment of the peg in relation to respective plates. |
| 4. | A fixture according to any one of claims 13, c h a r a c t e r i s e d i n t h a t the angle (α) between the first plate (11) and a verti¬ cal plane lies in the range 6° 16°, and is preferably 11°; and in that the angle (β) between the second plate (12) and a vertical plane lies in the range 74° 84°, and is preferably 79°. |
TECHNICAL FIELD
The present invention relates to a fixture for sup¬ porting objects so that the objects will be absolutely firm, i.e. will not shake or tremble, e.g. for sup¬ porting objects and hologram plates in the practice of holography.
BACKGROUND PRIOR ART It is known to examine and measure the extent of the deformation of an object with the aid of holography. Double exposure of hologram plates enables changes in shape to be made visible on a hologram, in the form of images having a larger or smaller number of stripes in different configurations. This enables extremely small changes in shape, e.g. deformations as small as 0.3 micron, to be measured, which is highly significant when monitoring the quality of or load testing mechanical constructions. In view of the very small dimensions con- cerned in this regard, it is important that shaking between objects being examined and hologram plates used to take the two exposures is prevented to the maximum extent possible. Previously, certain difficulties have been experienced in fulfilling these conditions without the use of excessively complicated and expensive arrangements.
An object of the present invention is to provide means which will enable two objects, e.g.industrial products and hologram plates, to be mounted in a manner which
will substantially prevent shaking from occuring and which will enable the same relative positions between the objects to be re-established subsequent to having moved one of said objects.
SUMMARY OF THE INVENTION
A fixture constructed in accordance with the invention includes two permanently and stabily attached plates, each of which is provided with a multiple of holes for the attachment of support pegs of particular con¬ figuration. These pegs are intended for supporting objects. The one plate forms a relatively small angle with a vertical plane. It is mainly this plate that will support an object to be examined, e.g. an industrial object. The other plate forms a relatively large angle with a vertical plane. It is this plate which will support a second object, e.g. a hologram plate and optionally also the industrial object, depending upon the shape and extension thereof. The particular con¬ struction of the fixture ensures that the objects achieve possitive and reproduceable abutment under the influence of gravity.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail with reference to the accompanying schematic drawings, where
Figure 1 illustrates from above a fixture con¬ structed in accordance with the invention;
Figure 2 is a straight-on front view of the fixture illustrated in Figure 1;
illustrated in Figure 1;
Figure 3 illustrates a holder for hologram plates with plates inserted;
Figure 4 shows a support peg from one side;
Figure 5 is a straight-on front view of the support peg shown in Figure 4; and
Figure 6 is a side view of an inventive fixture with inserted plate holders in greatly reduced scale.
DESCRIPTION OF A PREFERRED EMBODIMENT
The fixture illustrated in Figure 1 includes two plates 11 and 12 which are fastened stabily and permanently one to the other. The plate 12 has formed therein a multiple of holes, of which two are referenced 121, 122, which are intended for the attachment of screw-threaded support pegs and a holographic plate holder.
As will be seen from Figure 2 , the plate 11 is also provided with a multiple of holes, of which two are referenced 111, 112, which are intended for the attach¬ ment of screw-threaded support pegs. In the Figure 2 illustration the plate 12 has three support points, namely a hemispherical projection 21 located sym¬ metrically on the inner end of the plate, close to its attachment with the plate 11, and two symmetrically located legs 22 which can be displaced in holes in said plate. The two multiple of holes mentioned above are outwardly conical, so as to conform to the conical abutment surfaces of support pegs intended for screwing into the plates.
When the fixture 11-12 is placed on a flat, horizontal support surface, the plate 11 will form a relatively small angle a with a vertical plane, which angle, how- ever, is substantially different to zero, whereas the other plate 12 will form a relatively large angle β with a vertical plane, which angle, however, is is sub¬ stantially different to 90°. The angle a will preferably lie in the range 6° - 16° and will suitably be 11°. The angle β will preferably lie in the range 74° - 84°, and will suitably be 79°.
The holder illustrated in Figure 3 comprises a framework of two vertical posts 31, 32, the lower ends of which are screw threaded, and two horizontal struts 33, 34.
The lower ends of the posts are intended to be received in corresponding holes in the plate 12, the location of the holes being chosen with respect to the shape and extension of the object to be anchored to the plate 11. Located on the strut 33 is a hemispherical projection
331, whereas the strut 34 has located thereon two hemi- sperical projections 341, 342 and three support pegs 343, 344 and 345. As shown, the support pegs 343, 344 and 345 are intended for supporting abutment with the edge surfaces of a holographic plate 35, with the sur¬ face of the plate bearing against the projections 331, 341, 342.
Figure 4 illustrates a support peg 40 which has a coni- cal abutment surface and a screw-threaded part 401 for insertion into a hole in the plate 11, said peg being secured in the hole with the aid of two nuts. The screw- threaded part 401 of certain pegs is considerably shorter than the screw-threaded part of other pegs, these pegs of shorter screw thread being intended to be
conical abutment surfaces of the peg and the plate. Located on one end of the peg is a short pin 402, a longer pin 404, and a hemispherical projection 403. The relative positions of these elements will be apparent from Figure 5.
Figure 6 shows the fixture from one side thereof, with the fixture resting on a horizontal support surface. Figure 6 also shows the angles α and β formed by res- pective plates 11 and 12 with a vertical plane.
The holder 3 can be displaced vertically and is fixated or locked in selected positions, with the aid of lock nuts fitted to the screw threaded posts 31,32.