Justus Traut’s “Bull-nozed” Convertible Block Plane
In an April 2017 blog entitled “Justus Traut’s Bull-Nose Plane” I discussed a delightful little bull-nose plane from the Stanley Model Shop that was the product of Justus Traut’s inventive prowess (See Figure 1).
The plane is based on patent No. 291,815 granted to Traut on January 8th, 1884(See Figure 2). I wrote at that time that no known examples of Mr. Traut’s convertible bull-nose plane as shown in the patent drawings were known to exist.
But, much to my pleasure I recently discovered that I was wrong. Figure 3. shows just such a plane. This plane, also from the Stanley Model Shop, is identical to the plane shown in the patent drawings. This convertible bull-nose plane is a modification of the Stanley No. 120 block plane. For a discussion of the development of the No. 120 block plane take a look at my blog post from March 1st of 2017 at http://eaiainfo.org/2017/03/01/120-model-shop-prototype-block-plane-from-evolution-to-production/.
As a quick refresher, Figure 4 shows the developmental model for the No. 120 block plane. This plane has what appears to be the Model Shop number “1522” faintly visible on the lever cap. I really like this plane because it still has the layout lines, file marks and evidence of the hand work put in by the craftsman who made this plane; possibly Justus Traut himself. The body is bit longer at 7 5/8” and the cutting iron is bedded at only 16 degrees compared to 23 degrees seen on the production models of the No. 120.
The depth of cut adjustment on this developmental model is a compound lever adjustment patented by Justus Traut and Henry F. Richardson. The patent for this cutting iron adjustment mechanism was filed on December 27, 1876 and was issued as patent No. 176,152 on April 18th, 1876 (See Figure 5).
The compound lever cutting adjustment mechanism produces a mechanical advantage of 24 to 1. As a result, a 1/8th inch movement of the adjusting lever moves the cutting iron only 5 thousandths of an inch. This created a remarkably sensitive cutting iron adjustment mechanism, but it was expensive to produce and was really too sensitive for practical use. Figure 6 shows the cutting iron adjustment mechanism used on the first production model of the Stanley No. 120 block plane. The mechanism was simplified and is identical to the cutting iron adjustment mechanism used on the Liberty Bell line of planes made by Stanley for the 1876 Centennial Exhibition in Philadelphia.
The simpler cutting iron adjustment mechanism’s mechanical advantage was 12 to 1, meaning that a 1/8th inch movement of the adjusting lever moved the cutter 10 thousandths of an inch. This was still a very sensitive adjustment mechanism and was well suited for the work intended for the No. 120 block plane. 
The No. 120 adjustable block plane was put into production in 1876 (see Figure7). It’s 7 3/16ths inches long, and 2 inches wide with a 1 5/8ths inch wide cutting iron. The cutting iron is bedded at 23 degrees. This increase in the cutting iron angle allowed room for the improved cutting iron adjustment mechanism that was used on the production model. The front knob is turned from fruit wood (apple) and is friction fit into a raised cylinder on the toe of the plane. The lever cap has a raised five-point star in the center of the nicely curved palm rest. The lever cap slides under a 3/16ths inch diameter rod that is threaded into holes in the sidewalls of the plane. A large locking wheel with a threaded shank that screws into the underside of the lever cap is used to firmly hold the cutting iron in place. The number “157” is stamped into the bed at the heel of the plane and all of the plane’s surfaces are japanned except for the sole. This plane was first offered by Stanley in 1876 and sold for $1.00 while the No. 110 non-adjustable block plane sold for 70 cents.
Once in production, the Stanley No. 120 block plane underwent multiple minor changes (For more information see the No. 120 Type Study done by john g. Wells as noted in Footnote 2). Then, in 1878, Traut revised the cutting iron adjustment mechanism on the No. 120 block plane once again, making it very simple, and much less expensive to produce. This newer cutting iron adjustment mechanism wasn’t as sensitive as the earlier version, but it got the job done. He didn’t file a patent for this new cutting iron adjusting mechanism until June of 1879, and was granted patent No. 219,186 for this cutting iron adjustment mechanism on September 2nd, 1879 (See Figure 8).
The relevant claims in this patent refer to the cutting iron adjustment mechanism which Traut describes as an improvement on the adjustment mechanism shown in patent No. 176,152 granted to him and Henry Richards on April 18, 1876. The claims in this patent apply to the compound lever arm used as part of the cutting iron adjustment mechanism and to the finely serrated pad on the cutting iron adjusting mechanism. The serrations on this pad mate with the fine serrations on the back of the cutting iron. A subtle but key feature of these mated serrations is that the lever cap tightening screw is located directly over the serrated pad and that there is a very slight curvature to the serrated pad (See Figure 9).
Traut explains in the patent that , “…one of the advantages of this construction of the compound lever is that the connection with the plane-iron may be directly opposite the tightening-screw, so that fine serrations may be employed without any danger of disengagement by the springing of the plane-iron because the tightening-screw will not allow the iron to spring at this point.”
Figure 10 shows how the serrated pad is directly opposite the lever cap tightening screw and Figure 11 show the fine serrations on the back of the cutting iron that mate with the serrations on the pad on the cutting iron adjuster.
Now I’ll freely admit and at the same time apologize that the preceding information may have been a bit boring to many of you, but it does set the stage for the intriguing plane shown in Figures 3 and 12! Justus Traut obviously loved to innovate and was constantly looking for ways to improve the tools he’d developed. It would have been a logical and simple step for Traut to develop the bull-nose block plane shown in Figure 1 from the production models of the No. 120. At the time Traut was working on this bull-nose block plane the No. 75 bull nose rabbet plane was the only bull-nose rabbet plane available in the Stanley stable of woodworking planes. So, it would have required only a small conceptual step on his part to envision and produce this “convertible bull-nozed (sic) and common hand plane” shown in Figure 3. His concept was that of a “combination” bull-nose and block plane! The short pins on the nose piece slide nicely into the corresponding holes on the plane body and the long fastening screw holds the nose piece firmly in place allowing the plane to be used either as a bull-nose plane or as an adjustable block plane (See Figure 12).
Traut had to eliminate the front knob to make room for the attachment screw, but added a nicely designed finger rest. The plane is heavily japanned and the milling marks on the sole indicate that the sole was ground flat after the nose piece and main body of the plane were assembled. The cutting iron imprint is identical to those seen on the No. 120 planes between 1876 and 1894 See Figure 13).
Traut’s patent application for this plane was filed on November 23rd, 1883, so this plane was likely made in the late summer or early fall of that year. Patent No. 291,815 was granted to Traut on January 8, 1884 (See Figure 2). This plane never saw any use and appears to have spent most of its life on a shelf in the Stanley Model Shop.
While Traut may have been enthusiastic about this plane, it never made it into production. Stanley Rule & Level Company bought the rights to John Campbell’s patent No. 271,219 for a combination block plane and bull-nose plane shortly after it was granted on January 30, 1883, ten months before Traut filed his patent application for his combination bull-nose and block plane(See Figure 14).
Campbell’s patent describes a combination block and bull-nose plane that can be adapted to use as either a block plane or a bull-nose plane by simply reversing the position of the cutting iron (See Figures 15 & 16). Stanley quickly acquired the rights to this patent and by March 23, 1883 had submitted an application for a re-issue of Campbell’s patent that also assigned the patent to Stanley. Campbell’s patent was elegantly simple, much less expensive to produce and Stanley had it in production and for sale to their customers in early 1884, before Traut’s patent on his combination bull-nose and block plane was granted.
Traut was able to add another patent to his ever-growing list with this nicely designed plane, but the practical and always cost-conscious managers at Stanley opted to provide their customers a less expensive but probably equally effective plane. Despite that, isn’t it wonderful that these unique examples of Traut’s amazing skill are still around to help us appreciate his talent and inventive genius.
By Paul Van Pernis
 For a more thorough discussion of this cutting iron adjustment mechanism see my blog post titled, “Panics, Patents, and Liberty Bell Planes” at, https://eaiainfo.org/2017/04/21/panic-patents-and-liberty-bell-planes/.
 For more information regarding the early models of the Stanley No. 120 block planes and the various changes that were made to the plane see, “Early Models of the Stanley No. 120 Adjustable Block Plane”, by John G. Wells, in The Gristmill, No. 124, September 2006, pp. 14-19 and, “Update for the Stanley No. 120 Block Plane Type Study” by John G. Wells, in The Gristmill, No. 126, March 2007, pp. 18-19.
 The patent for the compound lever cutting iron adjustment mechanism was filed on December 27th, 1875 and was granted to Richards and Traut as patent No. 176,152 on April18, 1876. Traut and Richards applied for a re-issue of their patent on June 28,1876 and were granted reissue patent No. 7,565 on March 20, 1877.
 On the early versions of the No. 120 with this revised adjustment mechanism, the “pad” with the fine serrations was made of cast iron. Around 1880, the cast iron pad was replaced by a folded steel pad.
 For some information on the Stanley No. 75 Bull-nose Rabbet Plane see, https://eaiainfo.org/2015/06/10/stanleys-75-bull-nose-rabbet-planes-from-the-model-shop/.
 Justus Traut used the spelling “bull-nozed” in his patent.
 The No. 130 Block Plane described in the 1884 Stanley catalog as a “Double-Ender” sold for 80 cents. The No. 120 block plane sold for 85 cents in that same 1884 catalog.
 For more information on Justus Traut please refer to Don Bosse’s ongoing series of comprehensive and well researched articles on Traut in The Gristmill, Volume 174, March 2019, Volume 175, June, 2019, Volume 176, September 2019, and Volume 177, December 2019.