US2102938A - Keyboard balance - Google Patents

Description

Dec.'21, 1937. c. A. BECKER ET AL KEYBOARD BALANCE Filed Oct; 24, 1936 a Sheets-Sheet 2 TTORNYS- Dec. 21, 1937. c. A. BECKER ET AL 2,102,93$

KEYBOARD BALANCE Filed Oct. 24, 1936 3 Sheets-Sheet 5 so 50 G sou 200 mu INVEN OR Patented Dec. 21, 1937 PATENT OFFICE KEYBOARD BALANCE Christopher A. Becker, Nutley,

and William C.

Seyter, Union City, N. J., assignors to The Torsion Balance Company,

poration of New York New York, N. Y., a cor- Application October 24, 1936, Serial No. 107,310

10 Claims.

Our present invention relates to balances adapted for laboratory, analytical and assay work, and more particularly to such balances of the keyboard type having a rider-supporting member and means operable by depressible keys on the exterior of the balance for independently depositing a plurality of riders onto and removing them from said rider carrier.

Among the objects of the invention are the following: 1) to provide a keyboard balance wherein the riders are supported directly under the beam and in the central plane thereof; (2) wherein the rider support is so mounted as to permit depositing and removing riders while the beam is in swinging motion; (3) wherein the riders are deposited onto and removable from the support by vertically movable plungers; (4) wherein the riders can be deposited onto and removed from the rider support independently of each other 20 and wherein said riders can be removed from the support simultaneously; (5) wherein a guard is provided for preventing the riders from accidentally falling oil the rider plungers; (6) wherein the rider-operating mechanism is asso- 35 ciated with frictional means for holding any rider plunger in the position to which it is moved; (7) wherein the rider support is carried by a rod having a pivotal connection with the stirrup and the balance pan so that the depositing and 30 removal of weights on the pan will not cause tilting of the stirrup; (8) wherein the rider plungers are adjustable to insure simultaneous removal of the riders; and (9) to generally improve and simplify the construction and operation of such bal- 3'5 ances.

The manner in which We accomplish the foregoing and other objects not specifically enumerated will be apparent from the detailed description which follows, when considered in con- 40 junction with the accompanying drawings, which show a preferred embodiment of our invention, and wherein:

Figure 1 is a fractional perspective front view of a keyboard balance embodying our invention, the front sliding panel of the enclosing case being omitted.

Fig. 2 is a section taken substantially along the planes of the broken line 2-2 of Fig. 1.

Fig. 3 is a section taken substantially along the planes of the broken line 33 of Fig. 2.

Fig. 4 is a section taken'substantially along the plane of the line 44 of Fig. 2.

Fig. 5 is a perspective view on an enlarged scale of the rider-supporting member and its 55 associated carrying link.

Fig. 6 is an enlarged detail, partly broken away, showing the frictional means for holding the rider plungers in any position.

Referring to the drawings, in the several figures of which the same reference character is 5 employed to designate corresponding parts, let l0 indicate an enclosing case within which the balance mechanism is housed, said case resting upon a glass or equivalent plate II surmounting a base l2 which is provided with the customary 10 leveling screws 13, only one of which is shown. Mounted on the plate II is a column M which supports a beam arrest I5 provided with a central agate bearing [6 upon which the central knife edge of a balance beam I1 is mounted. De- 15 pending from the beam I1 is an indicator or needle l8 adapted to swing past an index plate l9. Dependingly supported from the ends of the balance beam I 1 when the beam arrest is lowered are a pair of balance pans and 2|, and coop- 20 crating therewith are the usual pan arrests 22 controlled by a push button 23 projecting from the front of the base. Extending through the side panels of the enclosing case are slide rods 24 upon which are mounted rider hooks g5. At the 25 front of the base is a key 26 for controlling the beam arrest, and mounted in the base I2 is a slide drawer 21. The balance parts as thus far described are conventional and are merely illustrative of a type of balance to which the present 30 invention may be applied.

According to the present invention we provide a novel key-operated mechanism for independently depositing a plurality of riders onto .and removing them from a rider-supporting member for iacilitating more rapid and accurate weighing operations. As herein disclosed, this novel construction comprises a rider-supporting member 30 consisting of a pair of spaced parallel walls 3|, the top edges of which are scalloped to provide recesses 32 for supporting U-shaped riders 33. The spaced walls 3| are secured in parallel relation upon the opposite faces of a supporting block 34 which is mounted upon a link 35. The 46 upper end of said link is pivotally connected to a depending arm 36 of a stirrup 31, while the lower end thereof is pivotally connected to a hook 38, which, in turn, supports the balance pan 2| by engaging in an opening in the top of 50 the pan frame 39. The link 35 and the arm 36 on the stirrup are disposed to lie in the central plane of the balance beam l1, and the rider-supporting member which flanks or embraces the supporting block of the link 35 is thus mounted to embrace said central plane and may be said to lie in said central plane.

Mounted on the plate H rearwardly of the scale pan ill by fastening elements to is an upright frame comprising a base ii, a pair of standards or uprights 52 which, at their upper ends, have forwardly-extending components 42, the latter being connected together by spaced cross-bars 63 and A, the latter centrally thereof being partially cut away to provide a clearance groove .5 for the link 35.

The cross-bar M has formed therein a plurality of vertical openings within which are mounted slidable plungers at, the said openings being in alignment with the space between the walls of the rider-supporting member so that the plungers may move vertically through said space. Each of said plungers isprovided with an enlarged head d'i which is longitudinally adjustable upon the plunger, and each head has a V- shaped recess therein, the bottom of which is in vertical alignment or in a common plane with a pair of aligned recesses 32 in the top edges of the rider-supporting member. These recesses are designed to support the U-shaped riders as; the recesses in the tops of the plungers being adapted to pick up and support said riders when it is desired to remove them from the ridercarrying member, while the recesses in the ridercarrying member are designed to have said riders deposited therein when the plungers are lowered. The downward movement of the plungers is limited by the engagement of a shoulder on the enlarged head thereof with the top of the crossbar i i, while the upper movement thereof is limited by overhanging bars 49 and 58 of cantilever construction which are mounted on the top of the cross-bar 6 3. y

, To deposit or remove riders and to control such action from the exterior of the balance case we provide a novel arrangement of links and levers, one operative unit of which is illustrated in Fig. 2 of the drawings, and a description thereof, it will be understood, will apply to each of said units. Each of these units consists of a lever or arm 5% pivotally mounted upon a fulcrum rod 52 supported in the standards e2, the forward end of said lever being bifurcated, as indicated at 53, to engage a. flattened end 3-6 of the plunger ed, a pivotal connection between the lever and the plunger being obtained by providing operating shoulders on the plunger by the use of a washer 54 and a split ring 55.

1 The opposite or rear end of each lever 5! is pivotally connected to the upper end of a, link or arm as, the lower end of which, in turn, is pivotally' connected to a lever 5'! which is fulcrumed intermediate its ends upon a pin 58 supported in brackets 59 depending from the plate ii, the forward end of ,saidlever 5? extending through the front of the base and being provided thereat with a key or button For guiding the levers 55 in their movements'the cross-bar 33 is provided with a plurality of parallel slots lfithrough which said levers extend.

The plunger operating units are suitably laterally spaced and in construction are nicely balanced so as not to impose undue weight tending to hold the lever in any predeterminedposition, with the objective in view that the slightest pressure upon the key or button Eb will serve to move the plunger controlled thereby. However, to'insure the plunger remaining in the position to which it has been moved, suitable friction means are provided. As herein shown, these controlled by said buttons.

consist of resilient leaf spring elements El disposed in slots 62 in a block or plate 63 mounted in the front wall of the base of the balance and through which slots the forward ends of the levers 5'? project. Covering this block 63 is a cover plate having cornplemental slots therein of slightly narrower width than the slots 62, so that the pressure of the spring elements'tl upon the levers 5i pressing them into engagement with a wall of the slots 55 will function to hold said levers and the plungers controlled thereby in any adjusted position until intentionally displaced.

Movement of the buttons 58 downwardly or upwardly will correspondingly move the plunger As each lever 5! is independently controlled it will be apparent that each plunger, which, in turn, controls the depositing or removal of a rider, will be thus independently controlled. The riders 33, it will be understood, will be of different weights, and to facilitate the reading of the weights thus added to the balance during a weighing operation, the front face of the cross-bar 4 5 may be suitably provided with value indicia of the respective riders beneath their respective positions, and the eys or buttons til may likewise be provided with such indicia so as to facilitate the weighing operation. g

In practice, when commencing a weighing operation, it is desirable to start with all the riders free from the rider-carrying member, and to facilitate the removal of theriders from the ridercarrying member we have provided a reset key 66. This key is mounted on the end of a lever 6'? which is pivoted intermediate its ends upon a pin $8 mounted in a bracket 59. The pin 68 also pivotally supports one end of a U-shaped reset bar it, the opposite end of which is pivotally mounted in a pin upon a complementary bracket "ii. The U-shap-ed reset bar at its end adjacent the lever '5? has an overhanging lip J?! which bears upon the end of the lever bl, which, in view of the weight of the reset bar, will hold the reset key it in its uppermost position. 'The reset bar iii normally rests upon a pair of brackets '53 connected tothe bottom of the depending brackets as which normally holds said bar in proximity levers 5? so that by depressing the reset key 56 the reset bar will be slightly raised to engage the levers 5? to move them upwardly, and, in turn, will move the plungers d5 controlled thereby upwardly to remove the riders from the ridercarrying member. To insure simultaneous engagement of the reset levers til, the bar is provided with an adjustable screw i i directly under each of the levers 51.

From the foregoing detailed description the construction and operation of the balance should be apparent. However, a few additional words of explanation might be helpful.- Accordingly, in beginning a weighing operation, after the balance is leveled and adjusted to equilibrium, the article or substance to be weighed is placed upon the left hand balance pan and the" major weights to counterbalance the object are added to the right hand balance pan. When the swing of the needle indicates that an approximate counterpoise has been added, the front panel of the balance is closed and the weighing operation is proceeded with by depositing the riders 33 upon the rider-carrying member by depressing, the lap propriate keys 60 and testingfor equilibrium.

Should perchance too great an amount of rider bar it) with each of the to the underside of the weights have been added, one or more of the riders may be independently removed from the rider-carrying member by moving the appropriate key 60 upwardly. When close balance has been obtained, the final accurate balancing will be consummated by moving the rider along the beam with the aid of the rider rods 24 and rider hooks 25. The total counterpoise weight will thus consist of the major weights on the balance pan, the rider weights on the rider-carrying member and the weight designated by the rider on the beam. These various weights can be readily read off and recorded. To place the balance in condition for a succeeding weighing operation the reset key may be depressed to remove all the riders from the rider-carrying member. overhanging bars 49 and 50 will act as guards to prevent the riders from falling off of the plungers upon which they are supported and from being thrown from said plungers by the sudden or violent movement of the keys controlling the movement of the plungers. The vertical movement of the plungers will also insure against the riders accidentally falling off their supports. The disposition of the rider-carrying member in a plane common with the central plane of the balance beam is conducive to accurate weighing, while the pivoted connection between the link depending from the balance beam stirrup and connected to the balance pan will insure against tilting of the stirrup upon the depositing and removal of weights from the pan.

It will thus be seen that we have provided a keyboard type balance capable of accomplishing the various objects set forth in the opening statement of this specification, and while we have shown and described a preferred embodiment of our invention it is to be understood that we do not wish to be limited to the precise details of construction, since the same may be modified within the range of engineering skill without departing from the spirit of our invention as defined in the appended claims.

What we claim is:

1. A balance of the character decribed, comprising a beam, a rider-supporting member depending from said beam, plungers vertically movable in the central plane of the rider-supporting member for depositing riders onto and removing them from the rider-supporting member, and means for independently moving the plungers.

2. A balance according to claim 1, wherein the rider-supporting member is disposed within the central plane of the beam.

The

3. A balance according to claim 1, wherein a stirrup is carried on the beam adjacent one end thereof, and the rider-supporting member is dependingly supported by the stirrup in the central plane of the beam.

4. A balance according to claim 1, wherein the rider-supporting member consists of an open frame through which the plungers are movable, said frame having spaced recesses for supporting riders thereon, and each of said plungers having a recess in its top in alignment with a recess in the frame.

5. A balance according to claim 1, wherein each plunger at its top has a rider-supporting head which is longitudinally adjustable on the plunger.

6. A balance according to claim 1, wherein means are provided for limiting the vertical movements of the plungers.

7. A balance according to claim 1, wherein there is a stirrup carried on the beam adjacent one end thereof, a link depending from the stirrup and a balance pan dependingly supported by the link, the rider-supporting member being connected to the link intermediate its ends, and the link being pivotally connected at its opposite ends to the stirrup and to the balance pan respectively.

8. A balance of the character described comprising a beam, a rider supporting member dependingly supported by said beam, plungers vertically movable through said rider supporting member while it is at rest or while swinging with the beam, for depositing riders onto and removing them from the rider supporting member, and means for independently moving the plungers.

9. A balance according to claim 8 wherein the rider supporting member consists of an open frame having spaced recesses for supporting riders in definite position thereon and where each of the plungers has a recess in its top in alignment with a recess in the frame.

10. A balance according to claim 8 wherein the rider supporting member consists of an open frame having spaced recesses for supporting riders in definite position thereon, where each of the plungers has a recess in its top in alignment with a recess in the frame and fixed means in spaced relation above the rider supporting member for limiting the upward movement of the plungers and preventing the riders from being thrown off from the plungers.

CHRISTOPHER A. BECKER. WILLIAM C. SEYTER.

Images