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July 23, 1946. w_ c_ SEYTER 2,404,601 MI CRO BALANCE Filed May'24, 1944 2 Sheets-Sheet 1 July 23, 1946. Y 2,404,601 W. C. SEYTER MI CRO BALANCE Filed May 24, 1944 2 Sheets-Sheet 2 ' 29 E U ‘I rl L... ‘ ii 1.91 6! BY 32 ‘ 2,404,001 Patented July 23, 1946 UNITED STATES PATENT OFFICE 2,404,601 MICROBALANCE William Christopher Seyter, Union City, N. J ., as signor to The Torsion Balance 00., New York, N. Y., a corporation of New York Application May 24, 1944, Serial No. 537,058 8 Claims. (Cl. 265—~54) 2 1 shown) extending outwardly at the front of the My present invention relates to balances, and case below the base thereof, the function of the lift rod being to move arrestment means for the more particularly to micro balances and aims to provide certain improvements therein. beam and the stirrups into and out of operative position. Rigidly mounted on the top of the col Among the objects of the present invention are (l) to provide a micro balance wherein the stir umn is a block I2 having mounted in its top a rup and the beam arrestment contacts are so ad~ central bearing consisting of an inset piece I3 justed that in releasing said arrestment means, of agate, boron carbide or other extremely hard the knife edges for supporting the stirrups will material having a highly polished plane top sur— seat-before the central knife edge of the beam; (2) wherein lateral tilting of the stirrups is pre~ 10 face for supporting the central knife edge I4 of a balance beam I5. Secured to the block I2 are vented when the pans supported by the stirrups a pair of arms I6 in which are ?xed aligned pivot are being loaded or unloaded; (3) wherein springs pins I1 upon which are pivotally mounted 9. pair are'provided to insure lowering of the arrest of oppositely disposed Y-shaped beam arrest ment arms for both the beam and the stirrups ment arms I8 and a pair of oppositely disposed when the lift rod controlling said arms is low Y-shaped stirrup arrestment arms I9 having ered; (4) wherein perfect placement of the rider fork-shaped end pieces I9’. Preferably the axis of the pivot pins ll lie in the top plane surface of the bearing member I3. The balance beam for facilitating such rider placement and the reading of the rider position on the beam; and 20 I5, which may be of any desired form, carries ad on sidewise; the beam (5) will wherein be obtained index means both are endwise provided jacent each of its ends an upwardly-directed (6) wherein the construction is less complicated and more easily adjusted in consonance with the extreme accuracy of the balance so that less time knife edge 20, and preferably the bearing edges of the knife edges I 4 and 20 all lie in a common plane. Adapted to be seatably supported upon will be required for making adjustments. The foregoing and other objects of my inven it an tion not speci?cally enumerated, I accomplish by the novel construction and cooperative ar rangements of parts hereinafter described and illustrated in the accompanying drawings show ing a preferred embodiment, and wherein: Figure 1 is a front elevation of the upper por tion of a micro balance embodying the novel fea tures of my invention, parts thereof being broken the terminal knife edges 20 when the balance beam is supported on its central knife edge are a pair of stirrups 2! each comprising a rigidly depending cradle 22 which, in turn, dependingly supports a > double hook-shaped member 23 through an intermediate link 23a. The hook shaped members 23 are adapted to support the bows 24 of balance pans (not shown). The balance beam I5 is adapted to be held in away to better illustrate the construction, the en closing case and the optical devices for reading “ arrested position, that is, with its central knife edge raised out of contact with the bearing I3 the swings of the index being omitted. Fig. 2 is a top plan view of the balance beam with the stirrups mounted thereon. by arrestment means herein shown as consist ing of a ball-shaped member 25 carried by an ad justable screw mounted adjacent one end of one of the beam arrestment arms I8 for cooperative engagement with a downwardly directed cup shaped member 26 carried by the beam, and by a pair of adjustable screws 21 carried by the other beam arrestment arm I8 for cooperative engagement with a transverse bar 28 carried by the beam. These beam arrestment means may be of a type well known in the art and more de tailed description thereof is not thought neces sary. The stirrup arrestment means consist of a pair of upwardly-extending adjustable screws Fig. 3 is an end elevation of the balance beam as viewed from the left end thereof, with the ». stirrups held in arrested position. Fig. 4 is a section taken substantially along the plane of the line 4-4 of Fig. 1. Fig. 5 is a detail section taken along the plane of the line 5——5 of Fig. 4. Figs. 6 and 7 are side elevations of modi?ed forms of rider lifters. Fig. 8 is a section taken along the plane of the line 8-8 of Fig. 7. Referring to the drawings, let the reference 50 29. carried by each of the fork-shaped end pieces IS’ on the stirrup arrestment arms I9, the free character I0 indicate a vertical hollow column end of one of said screws being adapted for co such as is usually mounted on the base of an operation with a downwardly-directed cup enclosed balance. and guided Within the column shaped element 30 carried by the stirrup and the fOr vertical reciprocation therein is a lift rod II which is usually operated by a thumb wheel (not 55 free end of the other screw being adapted for 3 4 cooperation with an inverted V-shaped groove member 3i carried by the stirrup. These stirrup 3!, by adjustably mounting on each of the stir rup arrestment screws 29 facing the front of the arrestment means likewise are of a type well balance a support 43a carrying a pair of upward known in the art, and further description there ly-extending adjustable screws £33 ?anking said stirrup arrestment screw .29 and providing the stirrup with laterally-extending ?ns 154 in overly of is not thought necessary. According to my present invention, the arrest ment and the seating of the beam and the arrest ment and seating of the stirrups are made to take place in a time sequential order, that is to ing relation to the screws (t3, the said screws be ing s0 adjusted in relation to the fins that in the normal arrested position of the stirrups as shown say, when the arrestment means are released, the ll) in the drawings, the free ends of the screws will stirrups will ?rst simultaneously seat upon the be closely spaced but in non-supporting relation terminal knife edges of the beam and at a short ' to said ?ns. interval thereafter the central knife edge of the beam will seat upon its bearing 53. This sequen tial timed seating of the stirrups and‘the beam is accomplished by employing the separate and in~ dependently operable beam arrestment arms I3 and stirrup arrestment arms 19 and by causing said arms to move at different rates by operation of the lift rod ll. This sequential timed move ment is brought about by connecting the lift rod I I to the arrestment arms l8 and l 5} through ad justable connecting rods 32 and 33, respectively, one end of each of said rods 32 being pivotally connected to a depending lug lta on one of the arrestment arms is and one end of each of said rods 33 being pivotally connected to a depending lug I?a on one of the arrestment arms l9, and lo My present invention also contemplates the provision cit‘ means whereby perfect placement of the rider on the beam will be obtained, both end wise and sidewise, and wherein means are pro vided for facilitating such rider placement and the reading of the rider position on the beam. To accomplish this I provide a rider carrier 155 which is mounted for movement, both longitudinally and ver ically of the beam. in any approved man ner. herein shown, the rider carrier 45 is ?x edly mounted on a carrier rod :26 which is guided along space rods 0,? to move parallel to the beam, said carrier rod also being rotatable about its Mounted on said rider carrier is a vertical ly--disposed tubular guiding member :18 within which is vertically and nomrotatably movable a plunger which, at its lower end, carries a rider rods 33 and the stirrup arrestment arms it at a 30 lifter 58. Vertical movement is imparted to the somewhat shorter distance from the pivotal plunger through a connecting arm 5i, one end mounting of said arms with the axis of the pins of which is ?xedly mounted on the carrier rod 46 l7 than the pivotal connections 35 between the and the opposite end of which is forked and strad rods 32 and the beam arrestment arms l8. In dles the ends of a projecting .pin 52 mounted on view of the disposition of the free ends of the ‘the plunger as and extending through vertical arms l8 above the arms l9, the latter have open slots 53 in the tubular guiding member 48. ings 19b therein through which the lugs ‘i811 ex The rider lifter 5%] comprises a pair of spaced tend and are movable. To transmit the motion of arms 5d, the free ends of which have reentrant the lift rod l i to the respective arrestment arms portions 55, the free ends of which, in turn, are I3 and I9 through the rods 82 and 33, the other 40 formed with notched aligned rider-supporting ends of said rods are pivotally mounted to a hori seats 5%. The rider lifter is intended for coop zontal‘ar-m 36 of a cross-shaped member 31 which eration with a rider 5'5 which is in the form of is rigidly secured to the lift rod H by screws 38 a straight piece of wire of circular cross-section, or equivalent means. Inasmuch as the lift rod 1 l the leng n of said rider being such as to extend 45 is mounted to move within the column If] and the across and project a slight distance on either side arm 36 must move therewith, the column is of the beam so as to be supportable in the seats formed with laterally aligned slots 39 to permit ?ll of the rider lifter when raised above the beam of such movement. To insure against any stick and to be seated on the beam when the rider lifter ing or lagging in the movement of the arrest is moved below the top of the beam. In this con ment arms when the lift rod is lowered, I provide 50 nection it will be obvious that the transverse dis pairs of springs All for bearing upon the stirrup tance between the reentrant ends of the rider arrestment arms l9 and pairs of springs M for arms is slightly greater than the depth of ‘the bearing upon the beam arrestment arms IIB. beam. so that in the vertical movement of said These springs may be of any desired form and rider lifter the arms will straddle the beam. The may be mounted in any convenient manner, and 65 top of the balance beam is preferably transverse are herein shown as leaf-springs suitably bent ly notched, as indicated at 58. to accommodate and rigidly secured to the top of the column by the rider, each notch indicating a predetermined fastening screws 42. ' weight when the rider is mounted therein. For In the loading and the unloading of the pans of facilitating the placement of the rider in any par the conventional analytical or chemical balance 60 ticular notch, the rider lifter is preferably formed there is always danger of causing a lateral tilt with an index pointer 59;: for aiding in indexing ing of the stirrups, so that when they are brought the notch on the beam with the rider when sup down into seating engagement upon the termi ported by the rider carrier. It will be observed, nal knife edges of the balance beam, such tilted however, that when the rider lifter has deposited stirrups will introduce an error in the weighing 65 the rider in a particular notch, that the arms of operation because of the change in the effective the rider would ordinarily obscure the rider from lengths of the balance beam arms between the the view of the analyst, and to remedy this con central knife edge support and the offset sup dition the rider arm facing the front of the bal ports of the stirrup-s, To overcome this source of ance case may be formed of transparent mate error, which, if inherent in micro balances, would. 70 rial such as “Lucite” or the like. The indexing constitute a major error, I provide means where and placement of the rider on the beam may be in such lateral tilting of the stirrups is prevented further expedited by the use of a magnifying when the pans are being loaded and unloaded. lens 59 adjustably carried by the rider carrier 45 This I accomplish by supplementing the con on an arm iii extending therefrom. ventional stirrup arrestment means 29, 3B and In Figs. 6, 7 and 8 I have illustrated alternative cating the pivotal connections 34 between the 2,404,601 5 taneously seat the stirrups and to thereafter seat forms of rider lifters whereby indexing of a notch the central knife edge of the beam. on the beam for placement of the rider therein 3. A balance comprising a column, a lift rod and for reading such position of the rider on the guided by said column, a balance beam having a beam can be accomplished. In each of the mod i?cations the rider lifter comprises a pair of spaced U! central seatable knife edge and terminal knife edges, stirrups seatable on said terminal knife reversely L-shaped arms 52 adapted in the ver“ edges, independently movable arms pivotally tical movement thereof to straddle the beam. In mounted on a common axis for arrestment of Fig. 6 the horizontal arms of the Us are each the beam and the stirrups, and rods of adjustable formed with a rider-supporting seat 63, and the arm facing the front of the balance is also pro 10 length connecting said lift rod with said arms, the connection of the rods with the stirrup arrest vided with an index 64. In Figs. 7 and 8 the rider ment arms being at a shorter distance from the supporting seats are formed at the ends of re pivotal mounting of said arms than the con entrant lips 55 on the horizontal arms of the Us, nec- ‘on of the rods with the beam arrestment and the arm facing the front of the balance is formed with indexes 66 and 61, the former being 15 arms for moving their respective arrestment arms sequentialiy, to ?rst simultaneously seat the stir for the purpose of indexing the notch on the rups and to thereafter seat the central knife edge beam for placement of the rider, and the index of the beam. 61 being for assisting in reading the position of 4. A balance comprising a balance beam having the rider when deposited on the beam. terminal knife edges, stirrups seatable on said The balance construction hereinbefore de knife edges, means for arrestment of the stirrups scribed, it will be understood, is intended to be comprising arrestment levers and cooperating housed within an enclosing case (not shown), and means on said levers and on the stirrups and in view of the extreme accuracy of the balance means for preventing lateral tilting of the stir such enclosing case may be provided with optical rups as the pans are being loaded and unloaded, means for facilitating the reading of the grad said last mentioned means comprising supple uations on an index member (not shown) carried mental cooperating means on the arrestment lever by the depending movable pointer 68 carried by and on the stirrups. the beam l5, and counterbalanced to adjust the 5. A balance comprising a balance beam having center of gravity of the beam by the adjustable 30 terminal knife edges, stirrups seatable on said nut 69. knife edges, means for arrestment of the stir In use the balance may be operated or manip ulated in precisely the same manner as conven tional analytical and micro balances, the funda mental distinctions between the present inven tion and prior balance constructions residing (1), in the timed sequential order in Which the stir rups are seated on the terminal knife edges of rups comprising arrestment levers and means on said levers and the stirrups, and means for pre venting lateral tilting of the stirrups as the pans are being loaded and unloaded, said last men~ tioned means comprising a pair of adjustable screws extending upwardly on each arrestment seated on its bearing upon release of the respec lever ?anking and supplemental to the means for arrestment of the stirrups, said screws being rod with the respective arrestment arms for mov edges, pivotally mounted independently movable ing them sequentially, to ?rst simultaneously seat arms for arrestment of the beam and the stir rups, means connecting the lift rod with the arrestment arms, means for operatively releasing said arrestment arms by operation of the lift rod the beam and the central knife edge is thereafter tive arrestment arms; (2) wherein the lateral tilt 40 adapted for engagement with laterally extending contact ?ns on the stirrups. ing of the stirrups is prevented when the pans 6. A balance according to claim 5 wherein the supported by the stirrups are being loaded and ends of the adjustable screws are closely spaced unloaded; and (3) wherein perfect placement of but normally in non-supporting relation to the the rider on the beam is facilitated, as is also the reading of the position of the rider on the beam. 45 contact ?ns on the stirrup. 7. A balance comprising a balance beam hav While in the foregoing description I have ex ing a seatable central knife edge and terminal plained the preferred embodiment of my inven knife edges, stirrups seatable on said terminal tion, it is to be understood, however, that I do knife edges, pivotally mounted independently not wish to be limited to the precise details of construction disclosed since these may be varied 50 movable arms for arrestment of the beam and the stirrups, means for operatively releasing said within the range of engineering skil1 without de arrestment arms to permit the seating of the parting from the spirit of my invention as de?ned respective knife edges in timed sequential order, in the appended claims. and spring means acting on said arrestment arms What I claim is: to insure their independent releasing movement 1. A balance comprising a column, a lift rod upon operation of the releasing means. guided by said column, a balance beam having a 8. A balance comprising a column, a lift rod central seatable knife edge and terminal knife guided by said column, a balance beam having edges, stirrups seatable on said terminal knife a seatable central knife edge and terminal knife edges, beam arrestment arms, stirrup arrestment arms, and adjustable means connecting said lift 60 edges, stirrups seatable on said terminal knife the stirrups and to thereafter seat the central knife edge of the beam. 2, A balance comprising a column, a lift rod guided by said column, a, balance beam having a central seatable knife edge and terminal knife edges, stirrups seatable on said terminal knife to permit the seating of the respective knife edges in timed sequential order and spring means mounted on the column and bearing on said arrestment arms to insure their independent re edges, beam arresting arms, stirrup arresting arms, and rods of adjustable length connecting 70 leasing movement upon operation of the lift rod. said lift rod with said arms for independently moving said arms subsequentially, to ?rst simul WILLIAM CHRISTOPHER SEYTER.