Valve Gears an outline

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3531 Tea Street N. W., Washington 7, D. C.

Mr. Frank L. McGuffin, 3531 Tea St., N.W., Washington 7, D.C. is good enough to agree to help us get out a book on Valve gears . It will cover some 30 valve gears as used on traction engines or were designed for the same. We give below an outline of the work by Mr. McGuffin for your criticism and you may be able to make some contributions. He is very anxious to get more material on the 'Springer' and 'Butterworth' valve gears. We shall be glad to hear from you - good or bad. - - Elmer.


On January 24, 1882, Louis C. Lugmayr was granted a patent No. 252,683 which was to lead the parade of valve gear patents using the sliding block.

I do not know whether or not Mr. Lugmayr sold his patent to Mr. Grime, but on November 17, 1885, John Grime was granted patent No. 330,782 and the drawings were very much alike, the main difference being that Mr. Grime used the inside sliding block instead of the outside block of Mr. Lugmayr.

On September 11, 1888 a patent No. 389,382 was granted to Mr. Grime; showing his improvements and it was this improved gear that was used on the P at Huron and other engines.

Not to be outdone on a good thing, Ellis J. Woolf and John Peebles added the 'Dowager's Hump' on the eccentric strap and were granted a patent No. 407,806 on July 30, 1889. And this was the famous Woolf gear used on the Case engines.

Ferdinand Kramer then put in his two-bits worth and on February 20, 1912 was granted a patent No. 1, 087, 977 but he still hung on to the notorious 'Dowager's Hump' (I have heard it called other names). It seems to me as I study the patent carefully, that Mr. Kramer had a very good idea but for offset 'Dagmar.'


On March 3, 1903, Abner D. Baker was granted a patent No. 721,994 on his center hung radial valve gear that was to become the leading valve gear of all time used on Traction Engines. It was tops.

Many hours of scheming and work were invested by various Inventors to develop a valve gear that would equal the Baker in performance.

Franz Wood used a curving sliding block instead of the center hung idea and was granted a patent no. 1,018,688 on February 27, 1912. This gear was used on the Wood Brothers engines and was a good gear.

Next to try his hand was John H. Gentry who developed a center propped gear and while it did not equal the Baker, it did get him a patent No. 1,022,232 on April 2, 1912.

More brazen than the others, William H. Miller took the Baker gear idea and mounted it on the engine instead of the boiler and was granted a patent No. 1,125,367 on January 19, 1915. This valve gear was used on the Keck-Gonnerman single engines and was as good as the Baker gear - in fact, it was the Baker gear engine-bed mounted.

I think one of the most interesting valve gears of the Baker type, was invented by Jay D. Purdy for which he was awarded a patent No. 1,752, 929 on April 1, 1930.

Mr. Purdy assigned his patent to the Pilliod Company, a branch of the A. D. Baker Company and it was known in railroad circles as the Baker gear. As the Purdy gear was a much better gear, it largely replaced the monkey-motion Walschaerts valve gear used on locomotives.


A patent No. 673,859 was granted to Harry C. Clay on May 14, 1901 for his valve gear invention. The Clay gear was used for many years on the Reeves engine and was an excellent valve gear.

On May 13, 1920 LeRoy Blaker filed his application for a patent and the patent examiner slapped interference against him in the form of the Quinn patent No. 606,358, which I think was quite far fetched.

While Mr. Blaker's invention was not radically new, it was a simplified application of the Clay gear, and as I see it, quite superior to any of the Lugmayr Class gears.

On March 24, 1925 Frank A. Browne was granted a patent No. 1,531,250 for his valve gear.

If you will look on sheet 1 of the Clay patent; sheet 1 of the Blaker drawing; sheet 3 of the Browne patent, I think you will agree with me when I say that the Blaker valve gear is a very simplified Clay and the Browne valve gear is a very complicated Clay.

Yes, I think Mr. Blaker would have been granted his patent for his valve gear if he had fought his case thru.


On December 28, 1886, George S. Strong was granted his patent, No. 355,035 for the valve gear he invented and it was a good valve gear.

A patent No. 1,033,532 was granted July 23, 1912 to William S. Brown, who later assigned it to the Southern Railway for use on their locomotives and it became known as the Southern Valve Gear.

The Brown gear was the same idea as the Strong gear but Mr. Brown used a crank instead of an eccentric.

On March 25, 1927, a patent No. 1,622,225 was granted to Mr. H. M. Harris. The Harris patent was practically the same as the Brown patent, except it was up-side-down. I think a close look at the Brown patent and the Harris patent will verify this.

Now that we have reached the end of the patents by classes let's take a look at the miscellaneous group of patents.


Patent No. 323,935 was granted August 11, 1885 to C. P. Hoist.

Patent No. 606,358 was granted June 28, 1898 to Fred Quinn, and this is the patent the Patent Office Examiner used to give LeRoy Blaker interference - disclosing the stupidity of the examiner.

Patent No. 635,625 was granted to Charles Weller October 24, 1889.

Patent No. 841,934 was granted to Sam Coffman January 22, 1907.

Patent No. 1,015,308 was granted to J. H. Gentry January 23, 1912.

Patent No. 1,075,778 was granted to J. H. Gentry October 14, 1913 and is a center propped valve gear that was used with success on the double cylinder Keck-Gonnerman engines, and was a very good valve gear.

The following patents are rather unusual and may be of interest to model makers.

Patent 490,308 to David Pitceathly, January 24, 1893.

Patent 961,316 to Victor E. Randall, June 14, 1910.

Patent 982,987 to Charles Pilliod, January 31, 1911.

Well, Elmer, I have worked pretty hard in digging out the enclosed patent copies, preparing my analysis of them for my own and others information, and I hope they will meet with your approval.

I do enjoy the letters your readers send in and I hope someone will shed some light on the 'Springer' and 'Butterworth' valve gears.