Published on Jan 10, 2016
The shaper is a reciprocating type of machine tool intended primarily to produce flat surfaces. These surfaces may be horizontal, vertical, or inclined. In general, the shaper can produce any surface composed of straight line elements. Modern shapers can generate contoured surface.
The metal working shaper was developed in the year 1836 by James Nasmyth an, Englishman.
Shapers are classified in number of ways depending upon the general features of design or the purpose for which they are intended. Shapers are classified under the following headings.
a. According to the type of mechanism used for giving reciprocating motion to the ram: - (a) Crank type (b) Geared type (c) Hydraulic type.
b. According to the position and travel of ram: - (a) Horizontal type (b) Vertical type (c) Traveling head type.
c. According to the type of design of the table : (a) Standard shaper (b) Universal shaper.
d. According to the type of cutting stroke: - (a) Push type (b) Draw type.
1. Table support, 2. Table, 3. Clapper box, 4. Apron clamping bolts, 5. Downfeed hand wheel, 6. Swivel base degree graduations, 7. Position of stroke adjustment handwheel, 8. Ram block locking handle, 9. Ram, 10. Column, 11. Driving pulley, 12. Base, 13.Feed disc, 14. Pawl mechanism, 15. Elevating screw.
In a universal shaper, in addition to the two movements provided on the table of a standard shaper, the table can be swiveled about an axis parallel to the ram ways, and upper portion of the table can be tilted about a second horizontal axis perpendicular to the first axis. As the work mounted on the table can be adjusted in different planes, the machine is most suitable for different types of work and is given name “ Universal “ . A universal is mostly used in tool room work.
The toolhead of a shaper holds the tool rigidly, provides vertical and angular feed movement of the tool and allows the tool to have an automatic relief during its return stroke. The vertical slide of the swivel base which is held on a circular seat on the ram. The swivel base is graduated in degrees, so that the vertical slide may be set perpendicular to the work surface or at any desired angle. By rotating the downfeed screw handle, the vertical slide carrying the tool executes down feed or angular feed movement while machining vertical or angular surface. The amount of feed or depth of cut may be adjusted by a micrometer dial on the top of the downfeed screw.
Apron consisting of by a screw. By releasing the clamping screw, the apron may be swiveled upon the apron swivel pin either towards left or towards right with respect to the vertical slide. This arrangement is necessary to provide relief to the tool while making vertical or angular cuts. The two vertical walls on the apron called clapper box houses the clapper block which is connected to it by means of hinge pin. The tool post is mounted upon the clapper block. On the forward cutting stroke the clapper block fits securely to the clapper box to make a rigid tool on the work lifts the block –out of the clapper box a sufficient amount preventing the tool cutting edge form dragging and consequent wear. The work surface is also prevented from any damage due to dragging.
In a shaper both downfeed and crossfeed movements may be obtained. Unlike a lathe, these feed movements are provided intermittently and during the end of return stroke only. Vertical or bevel surfaces are produced by rotating the downfeed screw of the toolhead by hand. Crossfeed movement is used to machine a flat horizontal surface. This is done by rotating the crossfeed screw either by hand or power. Rotation of the crossfeed screw causes the table mounted upon the saddle to move stroke so as bring the uncut surface of the work in the direct path of the reciprocating tool.