切割机外文翻译(共20页).doc

精选优质文档-倾情为你奉上毕业设计外文资料翻译题 目 网格刻线机 学 院 机械工程学院 专 业 机械工程及自动化 班 级 机升1002班 学 生 张静 学 号 指导教师 苏东宁 二一二 年 四 月 二 日United States Patent Office,Ser.No.739,123GRID RULING MACHINEJohn T Ferris, Houston, Tex.United States Patent OfficeAbstract This invention relates to grid ruling machine and, more particularly, to apparatus for effecting an accurate transverse ruling of a grid blank of extensive length.Key words grid ruling machineGRID RULING MACHINEJohn T Ferris, Houston, Tex., assignor to Dresser Indhustres: Incorporated, Dallas, Tex, a corporation of DelawareFiled June 2, 1958, Ser. No. 739,12311 C1aims.(Cl. 88-24)This invention relates to grid ruling machine and more particularly, to apparatus for effecting an accurate transverse ruling of a grid blank of extensive length.In the past grids have been ruled by machines using conventional mechanical drives and stop and start controls in conjunction with a reciprocating mechanical scribing carriage . However, it is apparent that the numerous increments of short movement of the carriage interrupted by a complete stop during the operating stroke of the scribing carriage permits a repeated back lash or play between the machine elements within the limits of manufacturing tolerances. Since perfect accuracy in the design and construction of conventional machine elements is unattainable, evenmore small errors in scribing are multiplied with repetition so that grids scribed by such machines are necessarily limited in length.More recently interferometers have been employed to control the longitudinal increment of movement of the scribing carriages but since interference fringes lose their brilliance and contrast to an unusable level beyond certain minimum limits of movement, grids of more than a few centimeters in length cannot be produced under conventional interferometer control.It is, therefore, an object of my invention to provide a machine capable of producing ruled grids of a length unlimited by the necessity of minimizing multiplication of machine errors, or by the limits of practical interferometer operation.It is a further object of my invention to provide a means for ruling grids during continuous motion of the ruling device along the length of the grid blank.It is a further object of my inversion to provide an inter interferometer having an operating range limited only by the length of the machine ways along which it is guided.It is a further object of my invention to provide a novel method of ruling a grid blank which does not requires start and stop increments of movement of the supporting carriage.It is a further object of my invention to provide a grid ruling machine that is automatic and, at the same time, reliable and accurate in operation. In carrying out my invention, I provide a pair of carriages adapted to move along well machined ways. Drive means and stop means which may be integrated are provided for independent movement of each carrier. Elements of an interferometer are arranged on the carriages, so that relatively movable elements thereof are separately movable. Control means are provided to move the carriages along the ways alternately, step by step, in increments within the practical range of the interferometer, with one carriage supporting a unique marking device that is operable during movement of that carriage. Thus, there is a setting stroke of one carriage, an active stroke of the marking carriage, a setting stroke and so. on until the full length of the ways has been traversed if desired. For marking the grid blank, I provide a coating of light sensitive emulsion on the blank arid employ as the marking device a source of light capable of exposing a fine line across the width of the grid blank. The source of light is fired at intervals during continuous movement of the marking carriage in response to signals generated by the interferometer.Other objects and advantages of my invention will become apparent from the description following when read in connection with the drawing wherein:FIG. 1 is an isometric view of my apparatus; FIG. 2 is a schematic plan view of the ruling machine. Referring now to the drawing, my grid ruling machine comprises two carriages l and 2 separately driven along .well machined ways by any conventional drive means such .as pinions 3 and 4, engaging racks 5 and 6 along the machined ways. Each gear 3, 4 is driven by an electric motor 7 and 8, preferably of the servo type so that the velocity, starting and stopping of the carriages l and 2 along the ways, can be maintained under close control. As is well known, the desired velocity control is achieved with a servo motor by modifying the current delivered thereto in response to variations in speed actually delivered thereby But-in any event, the specific drive means employed for the carriages is not material and the motors and gears described are shown by way of illustration only. Other speed control mechanisms such as speed reducers can be utilized to supplement the means shown. Moreover, other mechanisms such as constant tension springs or even gravity may be substituted as drive means. The important consideration in the apparatus to be hereinafter described is that means be provided to start, stop and otherwise control with extreme accuracy the movements of the carriages l and 2.The extent of movement of the carriages l and 2 is closely controlled by an interferometer 10 mounted thereon. The interferometer includes a source of monochromatic light, such as a cadmium vapor discharge tube 11 coupled with a narrow band filter 12. The near monochromatic light issuing from filter 12 is passed through a collimating lens 13 which directs a column of light into a dividing prism 14, comprising tw0 30-60-90 degree prisms 15 and 116 cemented together. Significantly, at least one of the prisms 15, 16 is aluminized at their union face 17 so that equal amounts of light will be reflected and transmitted by the plane of union, the reflected light being designated by the arrows R and the transmitted light by the narrows T. From the dividing prism 14 the reflected and transmitted light R and T pass into tetrahedral or corner prisms 18 and 19, respectively, which characteristically reflect light back along a path parallel to its path of entry, even though the prism is displaced in any direction transverse to such path of entry.After being reflected from their respective tetrahedral prisms l8, 19, the reflected and transmitted light R and T return to the dividing prism 14 where each is again divided by the plane of union 17. Here we are concerned with the transmitted components of the originally reflected light R and the reflected components of the originally transmitted light T both issuing from prism 14 along the lines R T toward a lens 20 which controls the diameter of the column of light impinging upon a shield or mask 21 having an annular aperture 22 there through which permits only a ring of light coincidental there with to pass and impinge upon a photoelectric cell 23 which converts pulses of light into electrical pulses.It will be noted that all components of the interferometer 10 are mounted on one carriage l except only one of the reflectors or tetrahedral prisms 18 which is mounted on carriage2 to move therewith. As is well known in interferometers, relative movement between the reflecting prisms 18 and 19 will vary progressively the phase relationship of the light reflected therefrom and reunited in its exit from dividing prism 14. That is, a prism movement of one-half wave length will increase the distance traveled by the light over both the paths of incidence and reflection of one full wave length. Consequently, after a relative movement of one-half wave length, the originally reflected and transmitted light waves R and T will exit toward shield 21 in phase again. By the same token, a relative movement of one-fourth wave length will cause the reflected and transmitted light R and T to exit from prism 14 in interference, i.e. one-half wave length out of phase. Consequently, continuous movement through the maximum light of phase coincidence and the darkness of interference produces a successively light and dark fringe pattern which from the collimated light l emitted from lens 13 is in the form of concentric rings moving outwardly from or inwardly toward the center, depending upon the direction of relative movement between reflecting prisms 18 and 19. As each ring of light in the fringe pattern produced assumes a diameter wherein it coincides with the annular aperture 22 of shield 21, a pulse of light impinges upon the photo-electric cell 23 to be converted into a pulse of electricity fed by conductors 23a to an electronic counter arid control circuit 24 for counting such pulses. Thus, relative movement between the reflecting prisms 18 and 19, and hence carriages l and 2, can be indicated by electrical pulses in increments of one-fourth wave length of the monochromatic light emitted from source 11. Of particular significance is the capability of my apparatus to extend this indication or measurement of minute increments over a total travel of the carriages l and 2 limited only by the length of the ways 5 and 6.The electronic counter and control circuit 24 functions to control the speed of the carriages l and 2 and the operation of electrical switches in accordance with the receipt of given numbers of electrical pulses. Through such switches, a source of alternating current 25 may be varied and selectively connected through conductors 26 and 27 to motors 7 and 8, respectively, driving carriages l and 2. For example, when the carriages l and 2 are in the position shown, a signal produced the counter and control circuit 24, will close an appropriate switch to direct current from the source 25 to the motor 8 for driving the leading carriage 2. During this movement intermittent fringes impinge upon photo-electric cell 23 to produce electrical pulses to be counted by control circuit 24. When a predetermined number of pulses have been counted, the circuit of motor 8 is opened to stop further movement of the carriage 2. The number of pulses measuring this movement is determined by the effective range of the interferometer 10. That is, the relative movement of this and, in fact, all interferometers must be within a range wherein the fringe pattern produced thereby is sufficiently sharp and brilliant to effect reliable functioning of the photo-electric cell 23. Therefore, assuming that the reflecting prisms 18 and 19 as illustrated in FIG. 2 are within the usable range, the carriage 2 may be moved until prism 18 has moved from the left of prism 19' (in FIG. 2) to the same distance to the right thereof.After the circuit of motor 8 has been opened, a delayed signal closes the circuit of motor 7 to move carriage I to the right in FIG. 2 and, hence, prism 19 first toward and then beyond prism 18 to the original position, shown in FIG. 2. Again, electrical pulses are fed to the counter and control circuit 24 until in response to appropriate signal the circuit of motor 7 is opened. Subsequently, motor 8 is energized and the cycle repeated.Therefore, it is apparent that the carriages1and 2 can be moved along over indefinite lengths in step by step stages measured in terms of one-fourth wave length of monochromatic light source 11. Such apparatus is particularly adapted to produce elongate grids by a novel means.Adjacent to the path traveled by the carriages1 and 2 is secured an elongate grid blank 30; of metal, glass plastic or the like. The grid blank 30 may be held stationary by any conventional fasteners, clamps or other holding means and disposed as shown with its longitudinal axis parallel to the ways 5 and 6 and its transverse axis perpendicular to the plane of the carriages 1 and 2. On the adjacent surface of the grid blank 30 is a coating 31 of a light sensitive emulsion requiring the maintenance of controlled conditions of area illumination to avoid inadvertent exposure.Mounted on carriage l to travel therewith is an elongate electronic flash tube 34 having its longitudinal axis disposed perpendicular to the plane of the carriage l and hence, parallel to the surface of the grid blank 30. the flash tube 34 has the surface thereof aluminized to prevent the transmission of light except through a narrow straight line slit 35 etched or scribed along the length thereof by accurate machine tool methods. Therefore each time the tube is flashed, a narrow, vertical bean of light is transmitted to and through a lens 35 a which focuses the beam to a narrow line of light impinging upon the light sensitive coating 31 to expose a fine line L transversely across the surface of grid blank 30.The flash tube 34 is energized upon closing of an appropriate switch in the control circuit :24 by the souro of stored electrical power of a conventional power supply and trigger circuit 36 and conductors 37. The control circuit is adapted to trigger the power supply each time a predetermined number of pulses are delivered by photoelectric cell 23 0nly during the movement of carriage 1.It is believed that the operation of my apparatus can now be readily understood. In response to appropriate signal the motor 8 is energized to move carriage 2 in advance of carriage l to set the grid ruling apparatus for operation. Throughout the movement of carriage 2, the power supply 36 is inactive. Then, carriage l is driven by motor 7 through a distance measured by a predetermined number of pulses delivered by photo-electric cell 23. Throughout this movement power supply 36 is operative and repeatedly on appropriate signal from control circuit 24 in response to a fixed number of pulses delivered thereto releases an electrical signal to energize the flash tube 34 and expose a narrow line on the face of grid blank 30. After exposure the light sensitive emulsion is processed by conventional photographic techniques. In the case of extremely long grids the developing process can be performed with the grid still in position by manual application of developing chemicals.Again, while I have referred specifically to a motor and gear and rack drive for the carriage, it is obvious that many different types of drive means may be employed. It is significant only that start and stop means for the carriage be under the control of mechanism operated in response to signals generated by the interferometer 10.While I have shown a preferred embodiment of my Invention, it is apparent that m any modifications an changes may be made therein without departing from the spirit and scope of my invention which is defined by the claims appended hereto.Having des