US 2163124 A
Description (OCR text may contain errors)
June 20, 1939. s. T. JEFFREYS ET AL 2,163,124
PHOTOSCULPTURE Filed Oct. 14, 1936 2 .Sheecs-Sheet l ATTRNEXLS Patented June 20, 1939 UNITED STATES 2,163,124 Y rnoroscmrmm Sidney Thomas Jeflreys and Henry John Petty, Newport, England, assignors to Photosculpture Limited, Newport, England, a British company Application October 14, 1936, Serial No. 105,529 In Great Britain October 16, 1935 2 Claims.
This invention relates to the production from a photographie record of models, copies or enlargements of the subject photographed, in solid material, such production being genera1ly known as photo-sculpture. The invention has reference to iniproved means for the production from photographs, of copies of theoriginal either enlarged, reducd, or of corresponding size and in solid material, and is more especially concerned H with the reproduction by photographie means of plane surfaces, e. g. surfaces having ornamentation, decoration or the like in the same or approximately the same plane, or plaques in relief or intaglid. Generaily the invention has refer- I 3 ence to the method of and apparatus for photosculpture as set forth in the specification of our British Patent No. 254,791.
The invention described in our British Patent Specification No. 254,791 relates to the 'produc- 20 tion from photographs of models, images, busts or the 1ike by a method in which during the photographie process the subject revolves, .or a1- ternatively the photographie apparatus is made to revolve about the subject, and in the process 25 of reproduction the block from which the model is produced rotates step by 'step relative to the cutting tool, or alternatively the cutting too1 revolves step by step about the axis of the block.
According to the present invention a photographie record may be made of a plane surface in the following manner, vizi; L
The method of photography and the photo graphie and lighting apparatus are substantiel? as described in British Specification No. 254,79 35 but according to this invention instead of the relative movements of the subject or object and the said apparatus being rotary, the apparatus is caused to travel parallel to or at a known angle to the surface of the object photographed, or alternatively the subject is caused to rilove acros's before the photographie and lighting apparatus in a straight line at right angles or a known angle to the beam of light projected by the lighting apparatus.
By present methods of photosculpture photographs are taken of the subject to be reproduced which record the outline of sections of the sub ject,- such sections according .to the method described in our prior British Specification No. 50 254,791,- being take naxially and through a common centre of the subject and according to the method described in the specification of our co pending British application No. 28,627 of 1935 such sections are taken radially from two or more 55 points about the circumference of the subject.
This invention relates to a method particulariy suitable for dealing with recording photographica1ly the shape and outlines 01 sections of subjects in relief or intaglio and upon a plane surface and from the photographie records se produced, or from guide sheets produced therefrom a model or copy of the subject may be repro duced from solid materia1.
The general method of obtaining the photographie record as described in the specification of ourBritish Patent No. 254,791 is utilised in this invention, namely; a. beam of light is projected upon the subject, such beam being partia1ly intercepted by a preferably straight edgcd screen (the edge of which preferably cuts the axis of the lens of the light projector) in such a manner that a sharply defined outline or profile is exhibited upon the subject as a shadow in a preferably vertical plane.
Whatever may be the shape of the subject, such shadow when viewd along the axis of the projector lens, appears as a straight line or a line corresponding to the edge of the screen and such shadow falls upon every surface of the subject in the same vertical plane and visible from the projector lens. In other words it follows the outline of en section of the subject taken at a known angle. When viewed from an angle in the same horizontal plane as the axis of the projector lensthe shadow appears (if the subject is of irregular outline) as an irregular line representing a true or foreshortened view of the outline of the section of the subject, according to the angle from which the shadow is observed. A photographie camera is angularly spaced from thesource of the beam of light, the angle between the axis of the projector lens and the optical axis of the camera lens being known and being hereinafter referred to as the light photo angle, and is operated to take a series cf photographs of the shadow as the shadow is caused to traverse the surfaces of the subject as hereinafter described, thus recording the outline cf sections of the subject at known positions taken verticaily and in parallel planes.
A camera and light projector are mounted upon the subject (and preferably at right angles thereto) to the opposite extremity.
The camera is angularly spaced from the projectorso that the respective axes of the projector lens and the camera lens (the angle between which is hereinafter called the lightphoto angle) intersect at or near the surface to be photographed.
During the movement of the recording apparatus a series of photographs is taken by the camera (the mechanism of which is suitably connected with the movement of the recording apparatus) which record the shape of the shadow at a known number of points, each photograph taken recording the shape of the outline of a vertical section of the subject taken along the line of the beam of light and at the point where it faces upon the subject at the time-the photograph is taken. By this method'a record is obtained of the outlines of any desired number et vertical sections of the subject taken at known positions and in parallel planes.
. ing the photographic process on which the beam of light falls at preferably all points of its travel and the object of which is to enable a record to be made on the photographie record of each outline of apoint a known distance from the recording apparatus.
The depth indicator consists of a strip having a vertical surface, horizontally placed at right angles to the beam of light and above or below the subject and in a position at, or at a known distance behind, the point of intersection of the axes of the projector and camera lens, and as more particularly described hereafter with reference to the accompanying drawings.
The apparatus for reproducirig the models comprises a control screen upon which the photographie records of each outline or guide sheets prepared therefrom (either of which are hereinafter included in the term recorded outline) are.optically projected or otherwise placed in position (the recorded outlines being corrected -to their true proportions if desired according to the method described in our prier British Specification No. 254,791) in a cutting or sculpturing machine adapted to cut or inscribe in a block of solid material an outline corresponding in shape to any sectional outline appearing on the control screen and in the same position relative to the block as the sectional outline appeared in the original subject when photographed.
The operation of the reproducing machine may be in part mechanical and in part manual, or may be entirely automatically controlled according to the method described in the specification of the pending British application of the abovenamed Sidne Thomas Jefireys No. 14,382 dated May 21, 1936.
In order that the said invention may be clea ly understood and readily carried into efiect, the same will now be further described with reference to the accompanying drawings in which:
Figure 1 represents in front elevation a subject upon a stand in position to be photogrphed.
Figure 2 represents in plan the subject as inprojector 3 is so mounted that the optical axis of its lens is at right angles to the direction of travel of the platform 5 and so that the lightphoto angle 6 between optical axes of the lenses of the projector 3 and the camera 4 is known and so that the said axes intersect at a. point 1 near the surface of the subject l.
The projector 3 is adapted to throw a beam of light 8 upon the subject l such eam being partially interrupted by a straight edged screen in such a manner that a sharply defined vertical shadow is projected upon the subject I and the depth indicator 9 hereiafter described. To eliminate uhwanted light the beam may be intercepted 'by a second screen so that in eiect a narrow vertical beam of light is projected.
Such beam when viewed along the axis of the projector lens,appears as a straight vertical lime whatever may be the contour et the surface of the subject, but when viewed from an angle, ap-
pears (if the contour of the subject is irregular) as an irregular line as illustrated by the line Il], s'uch lime representing a foreshortened outline of a section of the subject l'taken vertically along the fine-cf the beam 8, the degree of foreshortening depending upon the angle at which the line is viewed.
The platform 5 is adapted to travel horizontal-' number of known positions.
The operation of the camera 4 is preferably synchronised with the travelling movement of the platform 5 for instance by the rotating square section rod 14 operated by the pinion wheel I3 which is in mesh with the pinion wheel I2. Mounted on the square section rod M and rotating with it is a sliding pinion I5 which is adapted to travel with the platform 5 andwhich engageswith the pinion wheel l6 which is connecte'd with the camera mechanism by the shaft To facilitate accurate projection or setting of the recorded outline in the reproducing machine a depth indicator 9 is mounted above the subject I and parallel to the direction of travel of the platform 5, and in such a position that the beam 3 falls upon it during the whole of its travel: the surface of the depthindicator being vertically above or a known distance behind the deepest re-entrant surface of the subject l.
Upon a table l8 (Figures 3 and 4) is mounted a frame I! in which is ,fitted the control screen and a tool carrier 2l. the tool carrier being adapted to travel vertically upon guides 22, its
the tool carrier 21 is a drilling or cutting toc! 25 attached to a sliding member 25.
The sliding member 26 is carried in guides or slots in the tool carrier 2! and is adapted to'move hcrizontally in the directions corresponding with the feeding or withdrawal movement of the cutting 13001 25. v
The cutting tool may, according to the nature of the substance from Which the model is to be reproduced, be either a graving or a drilling or milling toc]; in the latter case tl ie drill or milling tool may be operated by an independent motor mounted on the sliding member 26,by a flexible drive 33 or by other suitable means.
The feeding and withdrawal movement of the cutting tool is controlled by the sliding member 26, which through the bevel pinions 21 rotates the square section shaft 28, upon which is fitted a. sliding pinion,29 adapted to follow the vertical 'movement of the tool carrier 2l, and which engages with a rack 30 fitted to the sliding member 26. r
Attached to the sliding member 26 is a pointer or line following device 3l touching or in close proximity to the surface of the control screen 20 and moving in unison with the cutting tool 25.
Also mounted on the table l8. is a sliding table 32 adapted to be moved horizontally intermittently and by -known degrees in a direction at right angles to the feeding and withdrawal move' ment of the cutting cool 25, the horizontal movement -being operated by the handle 34 and threaded shaft 35 which engages in a nui: fitted beneath the sliding table 32.
Engraved or marked upon the control scieen 'tool 25 willinscribe its first cut at a suiteble posi-:
tion near une extremity of the block I8.
Assuming that the recorded outlines 01' the subject I have 'been taken from left to right across" the surface of the subject and it is intended to project or place them on the control screen 20 in the same Order, then at the commencement of the reproduction process the bloc]: 38 will be positioned in relation to the cutting tool Il se A that the cutting tool will in its flrst cuttlng operation enterthe block 30 at or near -lts left extremity when viewed irom the cutting toc];
Th flrst recorded outline is then opticafly pro- Jected on the'control screen 2! in the-manner deacribed in the previous British Speciflcation No.
254,791, the foreshortening hein; optically corrected, (eithtrtullv or partially according to whether a true or corrupted reproduction la re- 'qired) by the method described in the said previous speciflcation, or. li. a guide sheet has been prepared from the photographie records, the
aune is placed in position on the controlscrn.'
then commenced and continues either steadiiy or intermittently to the end of its travel, the pointer 31 being caused to follow the outline 38 appearing on the control screen 20 by the operation of the'handle or crank 26. It will readily be seen that during this movement the cutting tool 25 will inscribe a line in the black 36 corresponding in shape to the outline 38 appearing on the control screen.
The next recorded outline is then similarly projected or placed upon the control screen and the table 32 moved horizontally so that the sec- -ond outline may be out in its appropriate position on the block 3G.
If the model to be reproduced is to be on the same scale as the original, then the recorded outlines projected or placed upon the control screen will be projected or placed true to scale, and between the cuttlng of each outline the table 32 and block 36 will be moved (if the model is to be reproduced in true proportion) the same distance as the beam of light 8 travels between each successive photograph in the photographie process, that is to say, if during each inch o! travel of the beam of light 8-forty photographs are taken by the camera 4 in the reproduction process, the table 32 will be moved one,fortieth of an in ch between the cutting of each outline in succession. A v A If the reproduction is on an enlarged or reducd sCale the recorded outline projected or placed upon the control scren 20 may be optically enlarged or reduced in projection (et enlarged or reduced guide plates placed in position) and in this case the movement of the table 32 between each successive cutting operation will be .proportionately increased or diminished.
What we daim and desire to secure by Letters Patent of the United States is:
I. Apparatus for obtaining a record of the surface co'ntour of a tablet-like object comprising an object holder, a platiorm movable in a path horizontally parallel past the face of the object, a light projector and a camera mounted on said platfcrm with their optical axes et an acute angle to each other and directed toward said object, said axes converging to a point adjacent said object, means in said' projector for casting a vertical shadow line on sid object, and means for operating said camera to take pictures of said object and shadow line thereon as said platform is moved horizontally in a path parallel to said object.
. 2. An apparatus for obtaining a record of the surface contour of a tablet-like object, including a platform movable horizontally past the object, a lizht projector mounted on said piatiorm and directed towards the object, an intermittenfly operated photographie camera aise mounted on said plattorm and dlsposed with its optical axis at an acute angle totl xe axis c! the light beam from the projector, means for casting a shadow line upon the object and-nieans for produclng parallel rectilinear movement of the light'beam and camera relative to the object while taklng successive photograpb3 of said shadow line, wherein the.light proje'ctor and the camera are mounted,'a screw operatively engaginx with the plati'orm to move it, and mechanisn: driven by said screw for operating the camera intermittentiy in synchronisation with the rnovennt o:
SIDNIZ' THOHA8 m. HENRY JOHN PIl1Y.