An Elliptical Ornamental Cutting Frame.Ref:wsnela.
Appears to be British made and of Victorian/Edwardian vintage,this tool measures approx 9.25in overall length.
Although designed to cut ovals/ellipses,the wheel train currently fitted produces 4 lobed designs.
The train is 96-48 to 48-96.The 3rd photo below shows the tangent screw.
Some basic patterns are shown in the last photo below,but many more can be produced,especially if the tangent screw is used,to sequentially phase or superimpose patterns.
The frame is usually mounted on the compound slide of a lathe,the work to be cut held in the chuck,the cutter in the frame.The frame pulley usually driven by an overhead line.
If the lathe in use has dividing gear to the headstock,the range of patterns can be expanded.
With appropriate cutters will cut wood and other "soft" materials as well as brass and other metals.
See Holtzapffel Vol 5,chapter 6 for a very good description of the use of this frame.
Price £750. SOLD.Please contact me for shipping costs or any other details.