US 3925897 A
Stereo, photogrammetric, plotting apparatus comprises a pair of projecting rods supported by universal joints. Each rod is associated with a plate-carrier carriage and is linked to the carriage by a joint in the form of a pin movable along a concave surface of the rod. Both rods are linked to a third carriage by a joint movable along the concave surfaces ot the two rods.
Claims available in
Description (OCR text may contain errors)
United States Patent 1 1 Ferri et al.
[ 1 STEREO-PLOTTING APPARATUS FOR AIR AND EARTH PHOTOGRAMMETRY  Inventors: Walter Ferri; Giulio Grassotti, both of Florence, Italy  Assignee: Officine Galileo S.p.A., Florence,
Italy  Filed: May 9, 1973  Appl. No.: 358,808
 Foreign Application Priority Data May 16, 1972 Italy 9483/72  US. Cl. 33/1 A; 33/20 D  Int. Cl. ..G01C 11/12; GOIC 11/24  Field of Search 33/1 A, 20 D [5 6] References Cited UNITED STATES PATENTS Santoni 33/20 D Dec. 16, 1975 2,753,756 7/1956 Santoni 2,847,906 8/1958 Santoni 33/20 D 3,302,291 2/1967 Czapek 33/20 D Primary Examiner- Richard E. Aegerter Assistant ExaminerRichard R. Stearns Attorney, Agent, or Firm-Haseltine, Lake & Waters [5 7] I ABSTRACT Stereo, photogrammetric, plotting apparatus comprises a pair of projecting rods supported by universal joints. Each rod is associated with a plate-carrier carriage and is linked to the carriage by a joint in the form of a pin movable along a concave surface of the rod. Bot'n rods are linked to a third carriage by a joint movable along the concave surfaces ot the two rods.
5 Claims, 5 Drawing Figures U.S. Patent Dec. 16, 1975 3,925,897
STEREO-PLO'I'IING APPARATUS FOR AIR AND EARTH PHOTOGRAMMETRY about a point constituted by a universal joint. Such ap- 1 paratus is described in Italian 491,889 and 672,314.
SUMMARY OF THE INVENTION According to the present invention, there is provided in stereo-plotting apparatus for mechanical photogrammetric projection, projection rods each having a concave surface, a plate-carrier carriage associated with each said rod, a respective pin slidable with respect to the concave surface of each rod, the said pin having an end portion which fonns a joint linking the rod with its associated carriage, a third carriage, and joint means linking the third carriage to the rods, the joint means being slidable with respect to the said concave surfaces of the rods.
Further according to the present invention, there is provided in stereo photogrammatic plotting apparatus, a pair of projection rods, a carriage associated with each rod, a respective joint linking each carriage with its associated rod, each said joint comprising pin means movable longitudinally along the rod, a third carriage, and joint means linking the third carriage to the rods, the joint means being movable along the rods on the same axis as said pin means.
In stereo-plotting apparatus having a fixed optical system and a movable plate, the joint between each carriage bearing one of the two photographic plates to be rojected and the associated rod which moves the carriage, is located between the universal joint which forms the centre of projection, and the joint which connects the rods to each other and to the third carriage of the coordinatometer. This latter joint can be made in two parts connecting the rods to the third carriage of the coordinatometer, when there is used for the projection cameras, the so-called Zeiss parallelogram arrangement.
In stereo-plotting apparatus having a movable optical system and a fixed plate, the plate-carrier carriages are replaced by a carriage which carries the first portion of the optical system.
The end portion of the pin can be in the form of a spherical head, or a non-spherical head when the socalled Santoni cam system is used to correct distortions.
BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the invention will now be described, by way of example only, with reference to the accompanying diagrammatic drawings, in which:
FIG. 1 is a schematic fragmentary perspective view of stereo-plotting apparatus in accordance with the pres- Pat'. Specification Nos.
FIG. 2 is a fragmentary side elevation, partially in section, of a modified form of the apparatus shown in FIG. 1;
FIG. 3 is a fragmentary side elevation, partially in sectiomof a modified form of the apparatus;
FIG. 4 'is a fragmentary side elevation, partially in section, of a further modified form of the apparatus; and
FIG. 5 is a horizontal section through the apparatus shown in FIG. 5. n
DESCRIPTION 'OF THE PREFERRED EMBODIMENTS The apparatus shown in FIG. 1 comprises a joint 1 5 which links projecting rod's'2 and 2' to a third carriage 3 of a coordinatometer which moves in' the X, Y and Z directions whereby'to move the rods 2 and 2 which are supported universal joints 4 and 4. The joint 1 included suitable conventional means (not shown) to hold the rods against the ball of joint 1. The joints 4 and 4' include respective brackets 40 and 40' adopted to be secured to the frame (not shown). The rods 2 and 2' act to move plate-carrier carriages 5 and 5 via joints 6 and 6' connected to pins 7 and 7. The plate-carrier carriages 5 and 5' are externally supported from the frame for slidable movement in their own planes as is entirely conventional.
The rods 2 and 2 are of semi-circular cross-section, and each of the pins 7 and 7' is slidable with respect to the concave inner surface of its associated rod 2, 2. In the embodiment in FIG. 2 the pin is shown at 7a and and is guided by two guides 8a and 9a.
In the modified arrangement shown in FIG. 3, the pin is shown at 7b and is guided in guide 8b, and in a sleeve 10b secured to the universal joint 4. FIG. 1 shows pin 7 guided by guide 8 and sleeve 10 said sleeve being secured to the associated rod 2 and supporting the associated universal joint by means of hinge 41.
As shown in FIGS. 4 and 5, the guide 8a is formed with a pair of rollers 8A arranged adjacent the joint 6 and the guide 9a comprises a pair of rollers 9A adjustable by means of an eccentric.
The pin 74 is retained by a pair of rollers 11, slidable along a longitudinal groove 2A on the outer surface of the rod 2, the rollers 11 being linked to the pin 7a by means of a resiliently biased arm 12.
A weight 13, connected via a parallelogram linkage (FIGS. 2 and 3) to the universal joint (4a in FIG. 2 and 4b in FIG. 3) maintains the rod 2 in equilibrium in every angular position thereof.
Since the joint 6 between the rod and the plate-carrier carriage, and the joint 1 between the rod and the third carriage of the coordinatometer is guided by the same guide surface (i.e., the semi-cylindrical inner surface of the rod), the axis of the rod and the axis of movement of the pin are automatically parallel. The center of the joint 6 between the rod and the plate-carrier carriage, when coincident with the rod axis, is always kept coincident during sliding of the pin along the rod. As evident from the drawing this coincidence of joint 6 with the rod axis and thereby also with joint 1 is preserved during the time when the distance f is varied in the course of varying distance 1 when carriage 3 is moved.
The apparatus particularly described is of relatively simple construction and has improved operational accuracy of the projecting rods, particularly when the portion thereof between the universal joint and the photographic plate to be projected, is moved in the space known as the image space.
What is claimed is: I
1. ln stereo-plotting apparatus for mechanical photogrammetric projection having a frame, a carriage movable along three mutually perpendicular axes, two projection rods each having a concave surface, a universal joint adapted to secure each rod to said frame of the apparatus, joint means connecting the carriage to the rods for universal movement, the joint means being movable with the carriage and slidable with respect to the concave surfaces of the rods along the axis of each rod, and a plate-carrier carriage associated with each rod and being operatively connected to means mounted on said frame for supporting said plate-carrier carriage for movement in its own respective plane, an improvement comprising means connecting each platecarrier carriage to its respective rod including a pin carried by means located on the upper portion of said rod for permitting axial sliding movement of said pin along said concave surface, said pin having a lower end, and a ball joint connecting said lower end of said pin to said plate-carrier carriage, said ball joint being axially 4 aligned in said rod with said pin and said joint means, and means mounted on each pin for guiding said pin along the concave surface of said rod.
2. Apparatus as claimed in claim 1, wherein said guiding means comprises respective roller means supported on each pin for guiding the pin along the said concave surface.
3. Apparatus as claimed in claim 1, wherein a surface of each rod opposed to the said concave surface has a longitudinal groove, said guiding means comprising bearing means movable along the groove, and resiliently biased linkage vmeans interposed between the bearing means and the pin to bias the pin towards the concave surface of the rod.
4. Apparatus as claimed in claim 1 further comprising cylindrical guide means mounted on each pin for guiding said pin along the associated concave surface.
5. Apparatus as claimed in claim 1, further comprising parallelogram linkage means at an end portion of each rod, and weight means carried by the linkage means for maintaining the rod in selected orientations.