Right hand side, you see a few pictures
of Counter Scales.
Touch a picture, if you want to see some details.
Shop / Counter scales incorporate
those items that can be used for a wide range of things.
They include the more common scales found in grocery stores in years passed, some of which may still remain in the produce areas of the large and small grocery stores. Some of these scales are very desirable, while others require large spaces or are so heavy that collectors may find them unappealing to collect.
A Roberval scale is an equal-arm
beam with the pans above the beam. The pans are stabilised by a leg and stay underneath
the beam. The principle was invented by a French mathematican, Gilles Personne de
Roberval, in 1669,to illustrate an enigmatic point in mechancs. The idea was not used,
apparently, until scales were made an this principle in the early 19 th C.
There are not many mechanical variations, but there are numerous decorative embellisments on tetter scales. In England, Robervals were most commonly used for trade scales and letter scales.
Later develpments of over-beam pan scales were devised by Beranger and Phanzeder, who both produced complex systems of stay and sub-beams to eliminate side loads on the bearings.
The Roberval system of leg and stay was also used in combination with most other types of resistant, spring, steelyards, pendulum and hanging pan. These devices replaced the weight pan. These types are known as Half-Roberval and Steelyard, Half-Roberval and Pendulum. etc. Demi-Roberval may also be used