Mettler Instrumente Ag

Mettler-Toledo Ag

Mottler-Toledo Ag

Ernst Strickler

Paul Luechinger

Hansueli Wild

Karl Bertsch

A precision balance for weighing flat filters has a funnel-shaped weighing dish. The weighing dish has a wall composed of a netting or a thin sheet steel provided with perforations. The weighing dish is mounted in a housing having a lower part and an upper part which is hinged to the lower part and can be swung away from the lower part. A cover vertically displaceably mounted in the upper part can be lowered onto the rim of the weighing dish. The weighing dish is grounded for discharging static charges on the filter.

Precision balance

The support arm (29) for the load-receiving pan (28) of an electronic weighing apparatus (2) is resiliently suspended from the vertically arranged load receiving member (15), thereby to isolate the load receiving member from deleterious forces applied to the weighing pan. To this end, one end of the support arm is suspended by a pair of parallel spaced leaf springs (31,33) from the lower end of the load receiving member. Opposed portions at the upper ends of the leaf springs contain relatively outwardly projecting horizontal U-shaped loop portions (43), thereby to afford resilient displacement of the arm in various directions relative to the load receiving member.

Weighing apparatus with resiliently suspended pan support arm

The cover for the weighing pan of an electronic scale is rotationally driven between closed and open positions relative to a housing by a friction drive arrangement including a clutch disc (37) and a friction disc (47). The motor drive is transmitted directly to the cover without any slippage. The cover may be rotated between its open and closed positions relative to the housing either manually (by overcoming the friction of the drive means) or by means of an electric drive motor. A control arrangement including contact fingers (19) and corresponding circular segment tracks (57) serve to monitor the position of the cover relative to the housing.

Weighing scale with cover operating means

In order to protectively support the weighing cell of electronic weighing apparatus within a housing and thereby isolate the weighing cell from external impact and shock forces, the weighing cell is mounted on the central portion of the relatively resilient printed circuit board of the electronic load measuring circuitry, which printed circuit board is supported at its edge or corner portions in spaced relation above the bottom wall of the weighing apparatus housing.

Electronic weighing apparatus having cushioned weighing cell support

Electronic weighing apparatus is provided including a force transmitting lever (17) pivotally suspended from a crossbar (33) that is connected for adjustment relative to the apparatus frame (9). An adjusting screw (45) adjusts the vertical position of the bar relative to a pillar portion (31) of the frame, and a fastening screw (37) serves to rigidly connect the crossbar with the frame following the crossbar adjustment. In this manner, the pivot axis of the transmitting lever is so adjusted as to minimize deflection of the no-load point owing to the inclination of the weighing apparatus.

Weighing apparatus with adjustable crossbar support

Electronic weighing apparatus (3) is provided including a transparent cylindrical cover member (13) defining a weighing chamber (1) within which the load weighing pan is contained. The cover member contains an access opening (16) and is rotatable about its axis relative to a concave housing wall portion within which it partially concentrically extends. The cover member is rotatable relative to the housing between closed and open positions in which the access opening is contained within and remote from the concave wall portion, respectively. A radially displaceable member (25) is biased by a spring (29) to close the access opening in a tightly sealed manner when the cylindrical cover member is in the closed position.

Electronic weighing apparatus having protective cover means

A coupling for transmitting a rotary motion in both directions of rotation. The coupling includes a drive shaft and a driven shaft and has a freewheeling capability in both directions of rotation for rotary motions introduced into the driven shaft. One or more balls are guided in a circular groove having an asymmetrical cross-section. The balls rest against a clamping disk having a non-circular cross-section. When the drive shaft is rotated, the balls are pressed against and clamped by a guide surface of the driven shaft.

Coupling for transmitting a rotary motion

A flexure or bending coupling member (10) is disclosed for precision scales and the like, including a pair of clamping end portions (12) joined with a central bar portion (18) via a pair of flexure portions (15), characterized in that the bar portion is arranged normal to the plane containing the end portions and the bending axes of the flexure portions. The central bar portion is connected with the flexure portions (15) via twisted portions (20) rotated 90.degree. about the longitudinal axis of the flexure coupling member, thereby affording improved resilience in the lateral direction and greater insensitivity regarding dimensional inaccuracies at the clamping locations and/or with respect to temperature variations.

Flexure coupling member for precision weighing apparatus

The pan assembly of a top-loading balance consists of a base attached to a pan carrier for joint movement in a vertically extending direction relative to a support on which the carrier is mounted. A sensible signal is generated in response to the presence of an object to be weighed on the pan assembly which, according to the invention, includes a cover spacedly superposed on the base and having a horizontally extending, exposed top face for receiving the object. One or more compensating weights are releasably interposed between the cover and base in weight transmitting relationship, the cover, the weights, and the base being closely similar in configuration when viewed from above and releasably secured to each other by interengaged projections and recesses.

Top-loading balance

The magnet system of a top-loading precision balance with electromagnetic load compensation is fixedly fastened in an aluminum alloy frame constituting the fixed link in the parallelogram suspension for the weighing pan. Distortion of the frame under thermal stresses due to the different coefficients of expansion of the ferrous metal of the magnet system and the light metal of the frame is prevented by openings in the frame walls spacedly surrounding the portions of the frame wall fixedly fastened to the magnet system.

Top loading precision balance

A single weighing pan of a top-loading balance is mounted on a vertically movable carrier spindle which transmits the weight of the pan and of a load thereon to an electromechanical transducer. Shock damage to the transducer is prevented by two superposed, star-shaped leaf springs connecting the pan to the spindle and jointly with the spindle, constituting a parallelogram linkage which prevents tilting of the pan under an eccentric load.

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Wolfhausen, Switzerland

Ernst Strickler