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Garvin Plain Milling Machines
Sizes 11,12 & 13
Garvin Home Page   
Plain Millers 131/2, 14 & 14A  Plain Millers 15 & 16A 

Garvin Plain Milling Machines were made for many years, in a variety of sizes, and the selection shown on these pages is typical of the firm's products during the early part of the twentieth century.
A new machine, the No. 14A, was added to the line in 1906 and this miller, together with the No. 16A, was provided with power feed and automatic trips and reversing feeds in all directions; newly developed square "ways" and a taper-gib strip for the saddle to knee adjustment were also introduced.
Garvin developed a patented and rather novel "
Direct, Constant and Positive Feed" system, where the slower rates of feed to the table were driven from the end of the milling spindle and the faster from the belt-drive countershaft; this system (which the makers claimed relived the spindle belt of 80% of the load) was only fitted to the larger machines, the Nos. 14, 14A and 16A.
In the same year the spindle cones on the three largest millers were widened and the numerical  ratio of the "back-gearing"  increased - both small modifications resulted in a claimed doubling of the machines' previous cutting power.
On the Nos. 13 and 131/2 millers, the table-feed cones were made interchangeable - which not only increased the feed rate by a factor of three, but doubled the number feeds to 24.
The tables, (except that on the No. 16A) were fitted with a large oil pan, with finished top edges, designed to keep coolant and chips from spreading over the machine and to increase the working surface of the table slightly.
All models were fitted with table-feed screws having what the makers described as
quick-pitch threads (-.e double-start) that gave one inch of travel per turn - handy for production work but not so useful when aiming for a precise setting. However, a side benefit of this specification - claimed the makers - was that the screws would not "start back"  if the table feed was tripped out when taking a cut.
Power was applied to the table-feed screws by a bronze or hardened-steel worm gear acting directly on the screw, with the assembly running continuously in oil. The table feed screw was fitted with one fixed and one adjustable nut - which meant that backlash could be removed entirely - and provided with a zeroing micrometer dial - making the task of setting spacing  work for rack cutting and locating holes (as in jig boring) rather easier than with a fixed dial.
The knees of all machines were made as stiff as possible, using a system patented on February 9th., 1904, where both the top and sides were completely enclosed - and so did not need sliding cover plates to protect the telescoping vertical-feed screws and the multi-thread, worm-and-gear knee-elevating mechanism. The extra stiff knee also made a better support for any arbor support braces it might have been required to carry..

Enclosed top knee casting

Interchangeable hand wheels were fitted as standard and the saddle adjusted to the knee by a taper rather than a screw-adjusted gib - so giving both better support and a finer means of adjustment.  The column base had an inadequately wide ledge cast around  the bottom to keep oil from spreading over the floor - however, something four times large in sheet steel might well have had a better effect
The overarm (on the very smallest machines, of an inadequate size to modern eyes) was formed from a solid ground bar and carried a yoke with two centers for "tit and  bush" bearings to support horizontal arbors - and two holes through which bolts could be passed to retain the optional stiffening braces that ran down to the knee. The largest machine, the 16A, was given two yokes for the overarm - one bushed so that it could be located centrally to stiffen the arbor; it's possible that this intermediate yolk was made in two parts - allowing it to be removed easily without dismantling so that other fittings (vertical-spindle attachments, for example) could be mounted on the overarm.
Besides the mounting points on the yolk, provision was made for attaching the braces to the end of the overarm  itself - so allowing a degree of flexibility in the way the operator could accommodate awkward jobs.
The early 1900s were a time of great change, when the various advantages connected with individual motor drives were beginning to be realised and Garvin, sensing the advances that were to come, were wise enough to offer a range of drive options including variable-speed as well as various combination of flat belt and gear drive - all to a customer's individual requirements..

Designed for lighter use the simple constructed Garvin No. 11 Plain Milling Machine had a longitudinal table travel of 12.5", in traverse of 4.5" and vertically 12.75".
Power feeds were supplied to the table by a vertical shaft within the main column which drove a worm wheel clutched to a pinion shaft within the knee.
The spindle carried a Brown and Sharpe taper and the machine weighed 650 lbs.

Garvin No. 12 Plain Milling Machine with a longitudinal table travel of 18", in traverse 6" and vertically 15".
Power was supplied to the table by an exterior telescopic shaft and a worm and wheel arrangement on the end of the table feed screw. This was the smallest machine in the range to be fitted with the quick-pitch table feed screw - giving one inch of travel to the single T-slot table per single revolution of the handwheel.
The No. 12 plain miller weighed 1016 lbs.

Garvin No. 13 Plain Milling Machine - the first in the range with all the features of the larger machines and based on the main casting of the No. 1 Universal model. The table had a longitudinal table travel of 24", in traverse 7" and verticaly, through a telescoping feed screw, of 19".
The table-feed pulleys were interchangeable, so enabling the feed rate to be doubled or tripled. The table feed screw was fitted with one fixed and one adjustable nut - which meant that backlash could be removed entirely - and provided with a zeroing micrometer dial that made (as the makers unnecessarily pointed out)
the task of setting spacing  work for rack cutting and locating holes (as in jig boring) "rather easier than with a fixed dial". The table was fitted with a micrometer adjustable stop.

Garvin Home Page   
Plain Millers 131/2, 14 & 14A  Plain Millers 15 & 16A 

email: tony@lathes.co.uk
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Garvin Plain Milling Machines
Sizes 11,12 & 13