Electric balance with scale on top

• US 4,619,337 A
• Filed: 03/26/1985
• Issued: 10/28/1986
• Est. Priority Date: 03/29/1984
• Status: Expired due to Fees

• Current Assignee: Sartorius Gmbh
• Original Assignee: Sartorius Gmbh
• Inventors: Melcher, Franz-Josef, Knothe, Erich, Ober, Jurgen, Behrend, Lothar
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Foster, Patrick W.
• Application Number:
  US06/716,082
• Time in Patent Office: 581 Days
• Field of Search: 177/185, 177/187, 177/189, 177/210 R, 177/210 EM, 177/211, 177/212, 177/245
• US Class Current: 177/210.00R
• CPC Class Codes: G01G 21/23 Support or suspension of weighing platforms G01G21/24 takes precedence
• CPC Class Codes: G01G 21/28 Frames, Housings

Abstract

In order to reduce the coupling-in of high-frequency electromagnetic interference into the measuring system of electric balances with scale on top and with a metallic balance scale and a metallic housing, a pin (7) which establishes the connection between the balance scale (2) and the load receiver (5) of the measuring system comprises an insulating layer on its surface which is bridged by a resistor (6) located on the pin (7).

Claims

1. Electric balance having a housing and a metallic balance scale which is located over the housing and is supported in a removable manner by at least one pin through at least one perforation in the housing on at least one metallic load receiver of a measuring system, characterized in that an insulating layer (8, 18, 28, 29) is located between the metallic balance (2) and the metallic load receiver (5) insulating the scale from the receiver, the insulation is bridged by a resistor means (6) located on the pin (7, 17, 27), the resistor means prevents electrostatic charging of the scale while also preventing electromagnetic alternating fields from affecting the balance.

2. Electric balance according to claim 1, characterized in that the pin (7) is located on the top of the load receiver (5) and extends into a corresponding cavity (11) on the bottom of the balance scale (2).

3. Electric balance according to claim 1, characterized in that the pin (17) is located on the bottom of the balance scale (2) and extends into a corresponding cavity (15) on the top of the load receiver (5).

4. Electric balance according to claim 1, characterized in that the pin (27) is constructed as a separate construction element and extends into a cavity (15,25) on the top of the load receiver and into a cavity on the bottom of the balance scale (2).

5. Electric balance according to either claims 1, 2, 3 or 4, characterized in that the pin (7, 17, 27) comprises a truncated cone-like end area.

6. Electric balance according to claim 5, characterized in that the pin (7, 17, 27) is manufactured from an electrically conductive material and the insulating layer (8, 18, 28) is located on the surface of the pin.

7. Electric balance according to claim 5, characterized in that the pin is manufactured at least partially from an insulating material.

8. Electric balance according to claim 5, characterized in that the resistor means (6) located on the pin is located in an approximately cylindrical, vertical hollow chamber (12, 16, 20, 34 24) of the pin.

9. Electric balance according to claim 5, characterized in that the resistor means (6) located in the pin has a resistance between 100 and 10,000 ohms.