US3004618A

US3004618A - Balance

Info

Publication number: US3004618A
Application number: US715010A
Authority: US
Inventors: Meier Johann
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-04-13
Filing date: 1958-02-13
Publication date: 1961-10-17
Anticipated expiration: 1978-10-17

Description

Oct. 17, 1961 J. MEIER 3,004,618

' BALANCE Filed Feb. 13, 1958 3 Sheets-Sheet 1 //VVENTOR Johan-n Meier By WW SQZW (A/21M Abkornegs Oct. 17, 1961 J. MEIER 3,004,618

BALANCE Filed Feb. 13, 1958 3 Sheets-Sheet 2 23 4, Lb\r\\\\\\\\\\\ l-jJ\|rI\\ INVENTOR (lo/wank; Meier Aiornegs Oct. 17, 1961 MElER 3,004,618

BALANCE Filed Feb. 13, 1958 5 Sheets-Sheet 3 INVENTOR Jokann Meier /Pm 5 & J m. A iorheys 3,004,618 BALANCE Johann Meier, Stafa, Switzerland, assignor to Erhard Mettler, Zollikon, Zurich, Switzerland Filed Feb. 13, 1958, Ser. No. 715,010 Claims priority, application Switzerland Apr. 13, 1957 p 7 Claims. (Cl. 177-248) This invention relates to a balance and more particularly to a laboratory or analytical balance having one or more removable ring-shaped weights and an operating device for mechanically placing these weights, in position and for lifting-off the same.

Objects of the invention are to providea balance of the type stated having a balance beam, a carrier, said balance beam having a center knife edge for its support and an outer knife edge for suspension of said carrier therefrom, a ring-shaped weight, supporting means on said carrier for horizontally supporting said ring-shaped weight, a pair of lifting-off members which are adapted to make contact with said ring-shaped weight from below at points on opposite sides of its centre of gravity for lifting off said ring-shaped weight from said supporting means, an operating device for simultaneously actuating said two lifting-off members, and a stop member disposed above said ring-shaped weight in such manner that said ring-shaped weight in its raised position is held between said two lifting-off members and said stop memher. A further object is to provide a balance of the kind outlined having a carrier suspended from the outer, knife edge of the balance beam, a set of ring-shaped weights graduated in such manner that any of said weights enclose with clearance the next smaller weight so that a smaller weight may be moved through the ring aperture of the next larger weight, supporting means on said carrier for horizontally supporting said ring-shaped weights in a position concentric to one another, a pair of liftingoif members for each of said ring-shaped weights which are adapted to make contact with the respective ringshaped weight frombelow at points onopposite sides-of its centre of gravity for lifting-off said ring-shaped weight from said suspension means, a stop member common for all of said ring-shaped weights and disposed above them in such manner that each of said ring-shaped weights in its raised position is held between its two lifting-oif members and said common stop member, a plurality of levers movable about horizontally disposed axes and extending below said set of ring-shaped weights for supporting said lifting-off members, and an operating device for actuating said levers in order to lift-off or to place on said ring-shaped weights in a predetermined sequence.

These and other objects and the advantages of the invention will best be understood from the following description of a specific embodiment when read in connection with the accompanying drawing, wherein like reference characters indicate like parts throughout the figures and in which:

FIGURE 1 is a vertical cross-section of a balance according to the invention taken on the line 1-1 in FIGS. 2 and 3,

FIGURE '2 is a longitudinal section of the balance, taken on the line 22 in FIGS. 1 and 3, and

FIGURE 3 is a horizontal section of the balance, taken on the line 3-3 in FIGS. 1 and 2. I

The casing of the balance, not shown in the drawing, encloses within its upper portion a cast intermediate base plate 4 with upwardly extending

stiffening ribs

5 and 6 and a column 7 which carries a bearing plate 8 for the main knife edge 9' of a preferably asymmetrical beam 10. The arm of the beam on the right, which is only partly United States Patent 3,004,618 Patented Oct. 17,1961

shown, carries a counterpoise which is not illustrated. The left hand shorter arm has a knife edge 11 at its end from which is suspended a carrier consisting of two

arching stirrup members

16, 17 supported by a bearing plate 12 by means of two compensating

links

14 and 15, attached to an intermediate member 13.

Members

16, 17 are arranged side by side and their upper ends 18, 19

are connected by

cross members

20, 21 whereas their lower ends are rigidly connected together by another cross member 24. -Attached to the lower cross member 24 is the load carrying hook 26 which projects through an opening in the intermediate base plate 4- and from which the pan 27 is suspended on rods 28.

The free ends of the

lower portions

22, 23 of the carrier 16 to 24 are bent outwards beyond the lower cross member 24 in the 'manner illustrated in FIG. 3 so that they form supports shaped somewhatlike the spokes of a Wheel and adapted to carry concentric ring-

shaped weights

29, 30, 31, 32. As will be seen'by reference to FIG. 2, the

lower portions

22, 23 are provided with V-shaped notches in which the ring-shaped weights 29 to 32 rest horizontally in a predetermined position, so that they cannot be laterally displaced. In the illustration according to FIGS. 1 and 2 only the ring-shaped weights 30 to 32 are shown resting on the supports 16 to 24, whereas the ring-shaped weight 29 has been raised from the supports. For the purpose of thus raising the weights 29 to 32 there are provided, in respect of each ring-shaped weight, two lifting fingers. In the drawing the lifting fingers 33, 34 are associated with the ring-shaped weight 29, the

lifting fingers

35, 36 with the ring-shaped weight 3%, the

lifting fingers

37, 38 with the ring-shaped weight 31, and the

lifting fingers

39, 40 with the ring-shaped weight 32. The lifting fingers 33 to 40 are the upwardly bent ends of levers 41 to 48 (FIG. 3) which as such are of equal length, and all of which extend below the ring-shaped weights 2:9 to 32, and are individually pivotable about a common shaft 4-9, As shown in FIG. 2

all the lifting fingers 33 to 40' have V-shaped notches which face upwardly and which are adapted to support the respective ring-shaped weight in the raised position, as exemplified in the case of weight 29. In its raised position the ring-shaped weight 29 is pressed by the two lifting fingers 33, 34 from below against a stop member 50 located above all the ring-shaped weights 29 to 32 and having the shape of a narrow stirrup, bolted by means of anupright shank 51 which rises beyond the periphery of the largest ring-shaped weight 32, to the intermediate base plate *4, as shown in FIGS. 1 and 3. FIG. 1 shows that in respect of each ring-shaped weight 29 to 32 the stirrup-shaped stop member 50 has a V- shaped notch which opens downward so that any one of the ring-shaped weights that is lifted will be held between the upward V-shaped notches in the lifting fingers and the downward V-shapcd notch in the stop member 50, as shown in the case of the ring-shaped weight 29. Since the points of contact of the ring-shaped weight 29 with the underside of the stop member 50' are in cross-wise arrangement in relation to the points of contact with the upper edges of the lifting fingers 33, 34 the ring-shaped weight 29 will be secured against lateral displacement also when it is raised.

If the two levers 41, 42 with their lifting fingers 33, 34 are tilted down, then thering-shapcd weight 29'will be deposited on the

lower portions

22, 23 of the carrier 16 to 24, the lifting fingers33, 34 continuing the downward movement until they reach the same end position asthat occupied by the other lifting fingers 35 to 40 (FIG. 2) in the drawing. The satisfactory operation of the arrange-ment that has been described when a ring-shaped I weight is being lifted or lowered presupposes that the two lifting fingers which lift or lower the ring-shaped weight apply themselves to points on the periphery of the ring-shaped weight that are as accurately as possible at opposite ends of the same diameter of the ring-shaped weight. During the actual lifting and lowering movement the ring-shaped weight will then temporarily be in a state of unstable equilibrium. On the other hand, it is an advantage if the raised ring-shaped weight can bear against the stop member 50 at points on a diameter which is preferably at right angles to the first mentioned diameter, as shown in FIG. 3. If this is the case the ringshaped weightalthough it may temporarily assume an inclined position on the lifting fingerswill be prevented from slipping out of the notches provided in the stop member and in the lifting fingers.

To permit the levers 41 to 48 and the associated lifting fingers 33 to 40 to be rapidly raised and lowered, the lever arms remote from the lifting fingers are acted upon by cam discs 52 to 59 (FIGS. 1 and 3) which are secured to a shaft 60 rotatably mounted in the

rib members

5 and 6. To ensure that the lifting fingers associated with the same ring-shaped weight are actuated in synchronism the

cam discs

52 and 53, 54 and 55, 5d and 57, and 53 and 59 are pairs of equal shape and secured on the shaft 60 in the same angular positions. Shaft 60 is parallel to shaft 49 and, in the same way as the latter, extends horizontally on one side of the periphery of the widest ring-shaped weight 32, so that each set of weights will require anarrangement of very low overall height. The end of shaft 60 which projects from the case of the balance, and which is not shown in the drawing, may carry a knob by means of which the weights can be deposited, in the sequence determined by the positions of the cam discs 52 to 59, on the supporting

members

22, 23 of the carrier, or conversely raised from the same.

To make the illustration clear the upper portion 18 to 21 of the carrier is shown in FIGS. 1 and 2 as being entirely above the stop member 50. However, in order to keep the structural height as low as possible the described balance will in practice be so designed that the stirrupshaped stop member 58 will project between the upper portions 18 and 19 and leave sufficient clearance so that the vertical distance between the upper portions 18, 19 on the one hand, and the

lower portions

22, 23 on the other hand will be accordingly reduced.

While in accordance with the provision of the patent statutes I have illustrated and described the best forms and embodiments of the present invention as now known to me, it will be apparent to those skilled in the art that other changes and modifications may be made in the apparatus described without deviating from the invention as set forth in the following claims.

I claim:

1. In a balance apparatus having a base, a balance beam pivotally connected to said base by main knife edge means, a carrier suspended from one arm of said balance beam by knife edge suspension means and including horizontal supporting means, and a plurality of concentrically-arranged spaced annular weight members removably supported on said horizontal supporting means; the improvement which comprises a horizontal stop member secured to said base and extending horizontally above and spaced from said supporting means and said weight members thereon, said stop member extending diametrically across said annular weight members and having longitudinally-spaced deformations in the lower surface thereof above diametrically opposed portions of each of said weight members, and means sequentially lifting said weight members upwardly from said supporting means into engagement respectively with the deformations in the lower surface of said stop member comprising a plurality of pairs of lifting members each arranged respectively below one of said annular weights, each pair of said lifting members being arranged to contact the associated weight member at diametrically opposed portions thereof, said stop member cooperating with said lifting members to hold secure against lateral displacement each of said ring-shaped weights, when in its raised position, in a crosswise arrangement between said lifting members and said stop member, and operating means sequentially raising said pairs of lifting members comprising a plurality of levers pivotally connected to said base and connected at their ends, respectively, to said lifting members, and means pivoting said levers in a predetermined order to sequentially move said annular weights vertically.

2. Apparatus as defined in claim 1 wherein each of said lifting members has an upwardly directed V-shaped notch therein and further wherein the deformations in said stop member comprise downwardly extending V- shaped notches, said notches cooperating upon upward movement of said lifting members to secure the annular weight member clamped therebetween against lateral displacement.

3. Apparatus as defined in claim 1 wherein each pair of said lifting members contacts the associated weight member at diametrically opposed portions lying in a vertical plane normal to said horizontal stop member, and further wherein said levers are all pivotally movable about a common horizontal axis which is parallel to said vertical plane and laterally spaced from said weight members.

4. Apparatus as defined in claim 3 wherein the horizontal supporting means of said carrier is connected to the upper portion of said carrier by a vertical portion extending between said common horizontal axis and said weight members.

5. The invention as recited in claim 1, wherein said levers can be tilted by means of cam discs secured to a common actuating shaft extending horizontally outside the periphery of the widest ring-shaped weight of said set.

6. The invention as recited in claim 1, wherein said lifting members are the upwardly bent ends of said levers.

7. The invention as recited in claim 1, wherein said levers are individually tiltable about a common shaft extending horizontally outside the periphery of the Widest ring-shaped weight of said set.

References fitted in the file of this patent UNITED STATES PATENTS 2,368,655 Fraps Feb. 6, 1945 2,764,400 Mettler Sept. 25, 1956 FOREIGN PATENTS 523,483 Great Britain July 16, 1940 719,985 Great Britain Dec. 8, 1954