LORCH Short-bed Lathes

Self-contained underdrive stand for the short bed lathes had the motor mounted on the back and driving down to a fast & loose pulley assembly contained within the cast-iron legs.

LORCH Precision Thread-chasing Lathes Type P
Models LLPV,  AIIP, BVIP and B-VI-PO-K
With a system also used by, for example, Wolf-Jahn, Karger and Auerbach, Lorch lathes with a headstock-type, sliding-spindle thread-chasing system were designated "P" Types - and designed to permit the perfect reproduction of short but very accurate threads of the type frequently used in optical, instrument and research workshops. In the Lorch design the master thread - or hob - was carried on the outboard end of the headstock spindle and engaged by a star-shaped follower which carried six different thread forms. The headstock, under the influence of the follower, was arranged to slide axially so that a thread-forming tool, held in the appropriate position, would cut a thread of exactly the same pitch. The follower could be disengaged at any point, or allowed to run off the master thread - hence allowing a degree of automatically positioning to be set up for each job.
Three different sizes of plain lathe could be fitted with the system, the LLPV, AIIP and BVIP with, respectively, centre heights of 2.5", 4" and 4.75", spindle bores of 10, 12.5 and 20 mm, spindle threads of M20, M27 and M39 and weights (bare machine) of 48 lbs, 101l lbs and 186 lbs.
Also was available with between centre capacities of 9 or 13 inches, the LLPV was driven by a 0.35 HP 2800 rpm motor, had 6 spindle speeds of 450, 630, 900, 1250,1800 and 2500 rpm.
A much more robust machine, the AIIP was available with a single between-centres capacity of 16 inches and, with the recommended 0.67 HP 1400 rpm motor, spindle speeds of 285, 400, 570, 800, 1140 and 1600 rpm.
Largest of all, the BVIP could be ordered with either 20 or 30 inches between centres and, using a 1.0 or 1.34 HP 1400 rpm motor had spindle speeds of 250, 350, 500, 700, 1000 and 1410 rpm.
Sliding-spindle lathes were not a Lorch invention; B.C.Ames in the USA had such a lathe is their lists during the early part of the Twentieth Century. However, its use was not for screwcutting but to allow collets to close onto work without drawing them back - and so permit precise turning to a shoulder or into a recess during production work--a system later fully developed by various makers of "Swiss Autos".

Apart from Swiss Autos, this early 1950s Lorch B VI PO-K was almost certainly the last lathe to be constructed with sliding headstock thread cutting.

LORCH Optical Thread-chasing Lathe
Type B VI PO

Early Lorch LL Precision Bench Lathe
Manufactured between approximately 1910 and 1920, the early Lorch LL lathe, left, was intended to be used for work with larger clocks and instruments - exactly along the lines of American precision bench lathes such as those made by Bottum, American Watch Tool Company, Bausch & Lomb, B.C.Ames, Cataract, Crystal Lakes, Derbyshire, Elgin, Hardinge, Hjorth, W.H.Nichols, Potter, Pratt & Whitney, Remington, Rivett, Sloan & Chace, U.N.D., Van Norman, Wade, Waltham Machine Works, and (though now very rare) , Frederick Pearce.
Of 90 mm (3.5-inch) centre height the lathe had a 24-inch long bed with the usual type of bevelled-edge top, a No. 1 Morse taper tailstock spindle and several distinctive features: "90-degree" ways to the top slide; a rack-and-pinion lever-action tailstock assembly built as an integral part of the unit; 6 screws firmly holding the end plate on to the cross slide; the top-slide T slot sitting in a section raised above the top surface (in a manner similar to that used by Pratt & Whitney); a T-slot let into the back of the cross slide; flat handles to the slide-rest; hand-rest screw locks and rather small diameter headstock bearings with a spindle that lacks a mounting thread but with the capacity to accept 15 mm Boley collets. In traditional fashion for this class of lathe the headstock spindle and bearings were, like those in a watchmaker's lathe, hardened, ground and lapped to as perfect finish as could be obtained.
With three flat pulleys instead of V-grooves for a round leather rope drive, this model must have been intended for heaver-tan-normal use and may well have been equipped, when new, with lever-operated slides.