Machine tool for grinding pins of a crankshaft

Claim 2

A machine tool for grinding pins of a crankshaft comprising: a headstock including a rotatable spindle, a footstock including a rotatable spindle aligned with said spindle in said headstock, clamping fixtures mounted respectively on said spindles and provided with bearing faces to support the crankshaft thereon with the axis of a pin or pins of the crankshaft being in alignment with the common axis of said spindles, means for clamping said crankshaft on said bearing faces, an indexing mechanism mounted in said headstock and operably rotating the crankshafT relative to said clamping fixtures for indexing and thereby positioning the axis of a pin or pins of the crankshaft in alignment with the common axis of said spindles, and work centers slidably mounted in said clamping fixtures for engaging and lifting the crankshaft by a predetermined distance away from said bearing faces by the advancement of said work centers whereby a pin or pins of the crankshaft may be indexed without any contact between the crankshaft and said bearing faces, the centerline of said work centers being offset from the centerline of the portions of the crankshaft supported on said bearing faces.

Claim 3

A machine tool for grinding pins of a crankshaft as defined in claim 1, wherein said indexing mechanism comprises an indexing disc having recesses on the periphery thereof, rotary means for rotating said indexing disc, switching means for producing signals to control said rotary means and a stop member for positioning the axis of a pin or pins of a crankshaft in alignment with the common axis of said spindles by engaging with said recesses.

Claim 4

A machine tool for grinding pins of a crankshaft as defined in claim 1, wherein said bearing faces are provided with outlets, means for supplying fluid under pressure through said outlets into a clearance between said bearing faces and the crankshaft while the latter is lifted away from said bearing faces by the advancement of said work centers thereby cleaning said bearing faces and the crankshaft.

Claim 5

A machine tool for grinding pins of a crankshaft comprising: a headstock including a rotatable spindle, a footstock including a rotatable spindle aligned with said spindle in said headstock, clamping fixtures respectively mounted on said spindles and provided with bearing faces to support the crankshaft thereon with the axis of a pin or pins of the crankshaft being in alignment with the common axis of said spindles, means for clamping the crankshaft on said bearing faces, and indexing mechanism carried by said headstock and operably rotating the crankshaft relative to said clamping fixtures for shifting a pin or pins of the crankshaft by a predetermined extent, act least one locating stop mounted in one of said clamping fixtures and regulating the indexing movement by said indexing mechanism so as to position the axis of a pin or pins of the crankshaft in alignment with the common axis of said spindles by engaging with a reference plane provided on the crankshaft, and work centers slidably mounted in said clamping fixtures for supporting and lifting the crankshaft by a predetermined distance away from said bearing faces upon the advancement of said work centers, whereby a pin or pins of the crankshaft are indexed without any contact between the crankshaft and said bearing faces, the centerline of said work centers being offset from the centerline of the portions of the crankshaft supported on said bearing faces.

Claim 6

A machine tool for grinding pins of a crankshaft comprising: a headstock including a rotatable spindle, a footstock including a rotatable spindle aligned with said spindle in said headstock, clamping fixtures respectively mounted on said spindles and provided with bearing faces to support the crankshaft thereon with the axis of a pin or pins of the crankshaft being in alignment with the common axis of said spindles, means for clamping the crankshaft on said bearing faces, and indexing mechanism carried by said headstock and operably rotating the crankshaft relative to said clamping fixtures for shifting a pin or pins of the crankshaft by a predetermined extent, act least one locating stop mounted in one of said clamping fixtures and regulating the indexing movement by said indexing mechanism so as to position the axis of a pin or pins of the crankshaft in alignment with the common axis of said spindles by engaging with a reference plane provided on the crankshaft, and work centers slidably mounted in said clamping fixtures for supporting and lifting the crankshaft by a predetermined distance away from said bearing faces upon the advancement of said work centers, whereby a pin or pins of the crankshaft are indexed without any contact between the crankshaft and said bearing faces, the centerline of said work centers being offset from the centerline of the portions of the crankshaft supported on said bearing faces.

Claim 7

A machine tool for grinding pins of a crankshaft as defined in claim 4, wherein said indexing mechanism comprises an indexing disc having recesses on the periphery thereof, rotary means for rotating said indexing disc, switching means for producing signals to control said rotary means, a stop member operably interrupting of said rotary means by engagement with said recesses, a driving pin operably connected with said indexing disc and entering into a reference recess provided on the crankshaft for indexing a pin or pins of the crankshaft and a spring means for resiliently connecting said driving pin and said indexing disc, thereby urging the crankshaft toward one of said locating stops.

Claim 8

A machine tool for grinding pins of a crankshaft as defined in claim 4, wherein said bearing faces are provided with air outlet ports, means for introducing air under pressure through said air outlet ports into a clearance between said bearing faces and the crankshaft while the crankshaft is lifted away from said bearing faces upon the advancement of said work centers, said air being discharged into the atmosphEre through said clearance, thereby cleaning said bearing faces and the crankshaft.

Claim 9

A machine tool for grinding pins of a crankshaft comprising: a headstock including a rotatable spindle, a footstock including a rotatable spindle aligned with said spindle on said headstock, clamping fixtures mounted on said spindles and provided with bearing faces to support the crankshaft thereon while the axis of a pin or pins of the crankshaft is in alignment with the common axis of said spindles, means for clamping the crankshaft on said bearing faces, an indexing disc rotatably mounted in said clamping fixture in said headstock, and provided with recesses on the periphery thereof, rotary means for operably rotating said indexing disc and being connected with said indexing disc by a shaft passing through said spindle in said headstock, switching means for producing signals to control said rotary means, a stop member operably interrupting the force of said rotary means by engagement with said recesses on said indexing disc, a driving pin operably connected with said disc and being engageable with a reference recess on the crankshaft for indexing a pin or pins thereof, spring means for resiliently connecting said driving pin and said indexing disc, at least one locating stop provided on said clamping fixture of said headstock and operably regulating the indexing movement to position the axis of a pin or pins of the crankshaft in alignment with the common axis of said spindles by engaging with the reference plane on the crankshaft, and work centers being mounted in said clamping fixtures free to advance and retract by a power means, said centers having conical ends for engagement with opposite ends of the crankshaft and operably lifting the crankshaft away from said bearing faces by a predetermined distance on the advancement of said work centers and engagement with the ends of said crankshaft, whereby a pin or pins of the crankshaft may be indexed without any contact between the crankshaft and said bearing faces, the centerline of said work centers being offset from the centerline of the portions of the crankshaft supported on said bearing faces.

Claim 10

A machine tool for grinding pins of a crankshaft comprising: a headstock including a rotatable spindle, a footstock including a rotatable spindle aligned with said spindle on said headstock, clamping fixtures mounted on said spindles and provided with bearing faces to support the crankshaft thereon while the axis of a pin or pins of the crankshaft is in alignment with the common axis of said spindles, means for clamping the crankshaft on said bearing faces, an indexing disc rotatably mounted in said clamping fixture in said headstock, and provided with recesses on the periphery thereof, rotary means for operably rotating said indexing disc and being connected with said indexing disc by a shaft passing through said spindle in said headstock, switching means for producing signals to control said rotary means, a stop member operably interrupting the force of said rotary means by engagement with said recesses on said indexing disc, a driving pin operably connected with said disc and being engageable with a reference recess on the crankshaft for indexing a pin or pins thereof, spring means for resiliently connecting said driving pin and said indexing disc, at least one locating stop provided on said clamping fixture of said headstock and operably regulating the indexing movement to position the axis of a pin or pins of the crankshaft in alignment with the common axis of said spindles by engaging with the reference plane on the crankshaft, and work centers being mounted in said clamping fixtures free to advance and retract by a power means, said centers having conical ends for engagement with opposite ends of the crankshaft and operably lifting the crankshaft away from said bearing faces by a predetermined distance on the advancement of said work centers and engagement with the ends of said crankshaft, whereby a pin or pins of the crankshaft may be indexed without any contact between the crankshaft and said bearing faces, the centerline of said work centers being offset from the centerline of the portions of the crankshaft supported on said bearing faces.

Claim 11

A machine tool for grinding pins of a crankshaft as defined in claim 7, wherein said bearing faces are provided with air outlet ports, means for introducing air under pressure through said air outlet ports into the clearance between said bearing faces and the crankshaft while the crankshaft is lifted away from said bearing faces by the advancement of said work centers, said air being discharged into the atmosphere through said clearance, thereby cleaning said bearing faces and the crankshaft from foreign particles and matter.