Faber-Castell has received many patents on his slide rules. An extensive list of them was published in the famous book "Slide rules" of Dieter von Jezierski.

Below you will find the complete collection of them in PDF format:

Year Number Description
1907 206428 Metal strips embedded in the stator and slide perpendicular to the scales, to improve stability.
1909 215722 Stator floor milled out for cubic scale. Applicant is Pickworth.
1922 365637 Stator parts connected by screws that permit adjustment of the slide action.
1926 450304 An adjustable half cyclinder lens in the cursor frame
1930 559664 Metal core fastened in plastic with rivets or screws.
1932 574594 Duplex slide rule with adjustable strap-joint
1933 596286 Duplex slide rule with adjustable strap-joint
1933 625535 Cursor for duplex slide rule
1934 1289083 Pocket slide rule
1934 1314631 Two-sided slide rule with markings that correspond on both sides.
1935 1348341 Cursor
1935 1354648 Darmstadt slide rule
1936 1394384 Slide rule
1936 655353 Slide rule with adding device (Addiator) on the back. Invented by C. Kübler.
1937 684135 Metal slide rule with plastic veneer
1937 1400134 Slide rule for surveying
1940 1484667 "Frameless" cursor
1940 1486119 Slide rule, Leipzig trade fair
1941 1506113 Slide rule
1951 804932 Measuring and calculating device for the graphic trades. Eventually produced as model 2/66. Invented by M. Schirmer.
1951 821840 Device for testing concrete. Invented by F. Kluge. Produced by Faber-Castell as their 2/62.
1951 873455 Duplex slid rule strap-joint that are screwed on and adjustable. Invented by Mr. Bachmann.
1951 873456 Cursor for duplex slide rule (adjustable). Invented by Mr. Bachmann.
1952 1018659a


Slide with 2 cursors and diagram. Produced as model 3/31 for reinforeced concrete. Invented by Mr. Bachmann.
1952 1062040 Window for Addiator inserted in floor or stator. Invented by Mr. Buelow.
1952 1115967a


Cursor which attaches around a single-sided slide rule (Mathema).
1962 1135686a


Slide rule with spring between slide and groove (to make slide operation smoother).
1964 1170170a


Groves on the flanges of the slide of plastic slide rules. Invented by Mr. Tegtmeyer.

 Last updated: 04-09-2009