350-211.‘ Oct. 1, 1946. ; v beam Iww _ A_ A, GRADlSAR 2,408,512 DEVICE FOR FORMING SLITS Filed Dec. 30, 1942 .....>) , eearcn NBC Patented Oct. 1, 1946 _ 2,408,512 ' UNITED STATES PATENT OFFICE 2,408,512 DEVICE FOR FORMING SLITS Albin A. Gradisar, Buffalo, N. Y., assignor, by mesne assignments, to American Optical Com pany, Southbridge, Mass., a voluntary associa tion Application December 30, 1942, Serial No. 470,563 10 Claims. (01. 88-61) 1 This invention relates to optical instruments and more particularly to a new and improved slit mechanism for use in optical instruments such as the spectrometer and spectrograph. An object of the invention is to provide a new and improved slit mechanism for optical in 2 illustrating an application of the present inven tion comprises a light source I, condensing lens 2, slit mechanism 3 and collimating lens 4. Aligned therewith is the prism 5 on the support ‘ 6 which support has adjacent its periphery the circular ?xed scale ‘I. Associated with said prism support 6 is a support having a Vernier 8 adapted struments which is relatively simple in construc to be moved relative to said ?xed scale 'I. Also tion. e?iclent in operation and economical to aligned with said prism 5 is the objective lens manufacture. system >9, reticules or crosshairs I0 and eyepiece Another object of the invention is to provide lenses II. a slit mechanism for optical instruments which It will be seen from the‘ above construction slit mechanism has an extremely sensitive open that the image seen in the eyepiece of the in ing and closing action. strument may be controlled by adjustment of the Another object of the invention is to provide a slit of the type set forth the jaws of which 15 adjustable slit mechanism 3 which is positioned between the source of light I and the prism 5 may be easily and quickly adjusted. and through which light from the light source I Another object of the invention is to provide passes to said prism 5. a slit mechanism of the type set forth in which As shown the condensing lens 2 focuses light there is no friction loss in the operation of the mechanism and which produces increased ac 20 from the source I on the slit 3. The slit then acts as a narrow brilliant aperture from which curacy while utilizing a relatively simple and the rays proceed to ?ll the collimating lens 4 economical construction. which renders said rays parallel for passage Another object of the invention is to provide through the prism 5. The refracted rays are a device of the type set forth in which there is no likelihood of any looseness and play or 25 then focused by the objective lens 9 in the plane of the crosshairs I0 and by moving the telescope backlash in the blade alignment. arm a ray of desired wavelength is brought to Other objects and advantages of the inven the crosshairs I0 and the slit image or spectral tion will be apparent from the following de light is examined through the eyepiece lens II. scription taken in connection with the accom panying drawing and it will be understood that 30 The size of the image observed is a function of the size of the slit and the magni?cation of the many changes may be made in the details of optical system. construction and arrangement of parts without The slit mechanism as shown in detail in Figs. departing from the spirit of the invention as 2, 3 and 4 comprises a base member I2 having expressed in the accompanying claims. I there fore do not wish to be limited to the exact de 35 formed integral therewith the side portions I3 and ?ange portions I4. tails of construction and arrangement of parts Secured to said side portions I3 are the sup shown and described as the preferred form has porting blocks I5 and I6 one pair on either side been shown by way of illustration only. of the opening I1 in said base member I2. These Referring to the drawing: ‘ Fig. 1 is a diagrammatic view of a spectrometer 40 blocks I5 and I6 are preferably all of the same size and are secured to said base I2 and the or spectroscope embodying the invention. side portions I3 symmetrically by the screws 46. Fig. 2 is a front view of, the slit mechanism. The blocks I5 and I6 are adjustable by adjusting Fig. 3 is a sectional view taken on line 3-3 the set screws 4'! one of which extends through of Fig. 2 looking in the direction of the arrows. Fig. 4 is a sectional view taken on line 4-4 45 the wall I2 and the other through the wall I4 so that each of said blocks I5 and I6 is posi of Fig. 2 looking in the direction of the arrows; tioned between two pairs of these screws 41 and which allows adjustment thereof and the block Fig. 5 is a perspective view of another form is further retained in position by the screws 46. ' of hinge connection. Referring more particularly to the drawing 50 The operation or adjustment of the screws 41 serves to position the knife edges of the two wherein similar reference characters designate corresponding parts throughout the several views, . slit jaws 44 and 45 in the same plane, while the spectroscope or spectrometer which is shown diagrammatically in Fig. 1 and which is of a rel the screws 46 serve to adjust the said knife edges of the two slit jaws 44 and 45 parallel atively simple type shown ‘for the purpose of 55 to each other. - 2,408,512 3 4 Screws 48 further serve to adjust the tension in the resilient reed members l8 and I9 by ad justing the distance between the blocks l5 or be employed. The resilient or spring member 4| is provided having its ends 42 and 43 engage ing the pins 3| and 32 respectively. This spring 4| eliminates the effect of the weight of the bell cranks on the adjustment of the slit jaws. When it is desired to operate the slit mech I9 are provided for each pair of said blocks or anism to open the slit jaws or increase the dis supporting members l5 and I8 respectively. tance between the said jaws 44 and 45 the screw These reed members are secured adjacent their member 35 is rotated by turning the knurled opposed ends to each or opposite ends of said 10 portion 31 which causes the end of said screw to bear against said interlocking portions 33 and supports I5 and I8 respectively by screws or the IE to which the ends of said reed members are attached. A pair of thin resilient reed members l8 and like 28. 34 on the pivoted lever arm to pivot said arms 4 21 and 28 respectively thereby causing the pins Each pair of said reed members I8 and I9 is secured adjacent its center to a ?oating jaw 3| and 32 to move said supports 2| in opposite support member 2| by means of the screws or 15 directions and parallel to their normal position the like 22 and said support members 2| have the to open said jaws 44 and 45 and retain the reduced extension portions 23 having block mem separation between said jaws uniform through bers 24 secured thereto by screws or the like ad out the entire length thereof. jacent the outer ends of said reduced portions The amount of the opening of the jaws can 23 and leaving a space between the block mem. 20 be read on the scale member 38'against the in bers 24 and the inner ends of said reduced dicator 39. When it is desired to close the slit portions. jaws the screw member 35 is rotated in an op The base I2 is provided with bearings for each posite direction by turning the knurled portion of the pivot pins 25 and 28. Pivotally mounted 31 and due to the resiliency of the reed mem by the pivot pins 25 and 28 are the lever arms 25 bers l8 and I9 the members 2| travel toward 21 and 28 respectively. each other in a direction parallel to their normal position to the extent permitted by the adjust The said lever arms 21 and 28 serve as bell ment of the screw 35 against the portions 33 and cranks to transmit motion from the calibrated screw to the slit jaws 44 and 45 through the 34. block members 24 and members 2|. The said 30 In Fig. 5 is shown a modi?ed form of pivot lever arms 21 and 28 are provided with the pins arrangement for the lever arm 28. This pivot arrangement comprises the ?exible reed members 3| and 32 respectively which are secured to said lever arms and engage the knife edge of the or the like 48 and 49. The member 48 is secured block 24. This arrangement utilizing the pins in at one end by screws or the like to the side engagement with the knife edges to move the 35 of the arm 28 and at its opposite end is secured ?oating jaw supports 2| applies the motivating by screws or the like to a block 50 which is force along the center of the system so that the secured to the support l2. The member 49 opposing force of the reed members will cause is secured at its opposite ends by screws or the neither rotation nor displacement of the slit jaws like to the end of the lever arm 28 and the block during adjustment of the slit. 40 5|. It win he noted that instead of single reed The end portions 33 and 34 of said lever mem members 48 and 49 that a plurality of such bers 21 and 28 opposite said pins 3| and 32 are members could be employed. preferably in interlocking relation and are It is pointed out that due to the reed arrange adapted to engage the end of the screw 35 which ment and parallelogram construction that the is threaded through the support 38 on the base 45 slit jaws 44 and 145 will always move in such a direction that the edges of said jaws are parallel l2 and which screw 35 is provided with the knurled head 31 for rotating the same. The throughout their entire length and also that a said screw is also provided with the scale ar smooth frictionless action is provided which pro rangement 38 which is adapted to be read in vides a low pressure on the closing of the jaws conjunction with the indicating member 39. Rotation of the screw 35 and consequent ad 50 thereby eliminating the possibility of damage to the jaws and also that the device is extremely sensitive and easily aligned and adjusted for parallelism of the plates. It is also pointed out that with the present justment of the arms 21 and 28 causes adjust ment of the slit jaws as described above. It will be noted that the movable or ?oating slit jaw supports 2| are ?oating on the resilient reed members I8 and I9 and are never in con tact with any other surface so that the motion construction a construction is provided‘ which provides increased accuracy and which yet is easy to assemble and adjust and relatively economical of these members is never impaired by sliding to manufacture. , - From the foregoing it will be seen that I have tremely sensitive to adjustment and whose 60 provided simple, e?icient and economical means hysteresis losses are reduced to a minimum. for obtaining all of the objects and advantages By hysteresis losses is meant a lagging or retard of the invention. ' ation of movement when the direction of the Having described my invention, I claim: movement of the members is changed. 1. A device for forming a slit of precisely ad It will also be noted that as the slits and slit 65 justable width for admission of a light beam in supports are secured to the center of a resilient a spectrometer or like optical system having, in reed member which reed member is anchored at combination, means providing a ?rst slit-de?ning its ends and under tension, that the slit laws are edge, a jaw member including a jaw providing retained in any position of adjustment under the second slit-de?ning edge opposed to said ?rst tension and therefore the possibility of misalign edge, means mounting said jaw member for ad justment movement in opposite directions normal ment is eliminated. Secured to the base |2 adjacent the opening to said slit toward and away from said ?rst slit de?ning edge, said mounting means comprising I‘! is shown the tubular member or mounting supports at opposite sides of the path of adjust ?ange 48 which may be varied according to the particular type of device with which the slit is to 75 ment of said jaw member and ?exible reed means friction losses. This results in a slit that is ex Search lice 2,408,618 5 . 6 _ ?xed to said member and to said supports and extending transversely of the path of adjust ment to ?oat said member between said sup ports, and adjustment means engaging said jaw at opposite sides of the path of adjustment of ment of said jaw member. member. the jaw member and ?exible reed means ?xed to said member and to said supports and extend ing transversely of the path of adjustment to member and manipulable in one direction to 5 float said member between said supports, and force said jaw member in one of its said opposite adjustment means comprising an actuator arm directions of adjustment against the yieldable for each jaw'member pivoted at a point spaced from one side of the member for pivotal move resistance of said reed means and in the reverse ment in a plane parallel to the path of adjust direction to control return movement of said jaw member by the release of tension of said reed 10 ment of said jaw member and positioned to en gage a portion of said jaw member on pivoting means, said reed means being so constructed and arranged as to support said jaw member in a in a direction away from the slit, and a call ?xed plane, and to be under tension urging said brated adjustment member connected to said actuator arms and manipulable in opposite direc jaw member in one of its said opposite directions of adjustment and into operating contacting en 15 tions to pivot said arms simultaneously and gagement with said adjustment means, at all equally in opposite directions, said reed means positions of adjustment of said jaw member. being so constructed and arranged as to sup 2. A device as claimed in claim 1 wherein said port each jaw member in a ?xed plane, and to reed means comprises ?at, elongate reed mem be under tension urging said jaw member toward bers of substantially greater width than thick 20 the other jaw member and against its actuating ness arranged edgewise to the plane of adjust arm, at all positions of adjustment of said jaw , '3. A device as claimed in claim 1 wherein said reed means includes at least two reed members 6. A device as claimed in claim 5 wherein said portion of each jaw member engaged by its ac attached to said jaw member and to said sup 25 tuator arm is an abutment extending on said member transversely to the path of adjustment ports at each side thereof, said reed members being spaced longitudinally of the path of ad and across the longitudinal center line of said justment of said jaw member. member, said abutment being engaged by said 4. A device for forming a slit of precisely ad actuator arm substantially at said center line. justable width for admission of a light beam in a 30 7. A device as claimed in claim 5 wherein said to said slit toward and away from said ?rst slit de?ning edge, said mounting means compris ing supports at opposite sides of the path of adjustment of said jaw member and ?exible 40 attached to the jaw member and to said sup ports at each side thereof, said reed members being spaced longitudinally of the path of ad justment of the jaw member. reed means ?xed to said member and to said 9. A device as claimed in claim 5 wherein said supports for said reed means are mounted for spectrometer or like optical system having, in reed means comprises ?at, elongate reed mem combination, means providing a ?rst slit-de?ning bers of substantially greater width than thick edge, a jaw member including a jaw providing ness arranged edgewise to the plane of adjust the second slit-de?ning edge opposed to said ?rst ment of said jaw member. ‘ edge, means mounting said jaw member for ad 35 8. A device as claimed in claim 5 wherein said justment movement in opposite directions normal reed means includes at least two reed members supports and extending transversely of the ‘path of adjustment to ?oat said member be tween said supports, and a?ustment means en independent adjustment movement toward and away from each other and also in parallel planes gaging said jaw member and manipulable in 45 substantially normal to the plane of said jaw ' one direction to force said jaw member in one member. 10. A device for forming a slit of precisely ad justable width for admission of a light beam means and in the reverse direction to control in a spectrometer or like optical system having, return movement of said jaw member by the 50 in combination, means providing a ?rst slit de?ning edge, a jaw member including a jaw release of tension of said reed means, said reed of its said opposite directions of adjustment against the yieldable resistance of said reed means being so constructed and arranged as to providing the second slit-de?ningedge opposed support said jaw member in a ?xed plane, and to said ?rst edge, means mounting said jaw to be under tension urging said jaw member in member for adjustment movement in opposite one of its said opposite directions or adjust 55 directions toward and away from said ?rst slit ment and into operating contacting engagement de?ning edge, said mounting means comprising with said adjustment means, at all positions of supports at opposite sides of the path of adjust adjustment of said jaw member, said adjustment ment of said jaw member, ?exible reed means means being so arranged and engaged with said _ ?xed to said jaw member and to said supports jaw member as to apply pressure thereto only in 60 and extending transversely of the path of adjust a direction parallel to the longitudinal center ment to ?oat said jaw member between said line of said jaw member and substantially at supports, means mounting said supports for in said center line whereby to maintain said jaw dependent adjustment movement toward and member in predetermined alignment with said away from each other and also in parallel planes ?rst slit-de?ning edge throughout adjustment of 65 substantially normal to the plane of said jaw said jaw member. member, and adjustment means engaging said 5. A device for forming a slit of precisely ad jaw member and manipulable in one direction to justable width for admission of a light beam in a force said jaw member in one of its said op spectrometer or like optical system having, posite directions of adjustment against the yield in combination, a pair of opposed, slit-de?ning 70 able resistance of said reed means and in the jaw members each comprising a jaw having a reverse direction to control return movement of slit-de?ning edge, means mounting said jaw said jaw member by the release of tension of members for'adjustment in parallel directions toward and away from each other, the mounting said reed means. means for each jaw member comprising supports 75 ALBIN A. GRADISAR.