Abstract: An automatic screw machine (20) has a body (22), and a head (21) that is rotatably mounted on the body and that is adapted to be selectively rotated relative to the body between any of a plurality of index positions. The body and head have closely-spaced and facing bearing surfaces (25, 28 and 26, 29), have spindles (23) journalled on the head for rotation relative thereto, and have a source of pressurized lubricant.

Abstract: The present invention provides an improvement for use in a machine tool having a spindle (51) mounted in a body opening (30) for axial and rotative movement relative to a body (31). The improvement includes a bearing assembly (25) that permits spindles (S1, S2, S3, . . . ) to be quickly exchanged while obviating the need to recenter a replacement spindle with respect to the opening after the original spindle has been initially center therein. The improved bearing assembly (25) broadly includes: a ferrous tubular sleeve (29) mounted in the body opening, the sleeve having an outer surface (40) arranged to face toward a portion (31) of the body that surrounds the opening and having an inner surface (36, 39) arranged to face toward a penetrant portion of the spindle; and a tubular bearing (46) arranged within the sleeve, the tubular bearing having an outer surface (51) arranged to face the sleeve inner surface and having an inner surface (50) arranged to face the spindle penetrant portion.

Abstract: The present invention provides an improvement for use in a machine tool having a spindle (51) mounted in a body opening (30) for axial and rotative movement relative to a body (31). The improvement includes a bearing assembly (25) that permits spindles (S1, S2, S3, . . . ) to be quickly exchanged while obviating the need to recenter a replacement spindle with respect to the opening after the original spindle has been initially center therein. The improved bearing assembly (25) broadly includes: a ferrous tubular sleeve (29) mounted in the body opening, the sleeve having an outer surface (40) arranged to face toward a portion (31) of the body that surrounds the opening and having an inner surface (36, 39) arranged to face toward a penetrant portion of the spindle; and a tubular bearing (46) arranged within the sleeve, the tubular bearing having an outer surface (51) arranged to face the sleeve inner surface and having an inner surface (50) arranged to face the spindle penetrant portion.

Abstract: An automatic screw machine (20) has a body (22), and a head (21) that is rotatably mounted on the body and that is adapted to be selectively rotated relative to the body between any of a plurality of index positions. The body and head have closely-spaced and facing bearing surfaces (25, 28 and 26, 29), have spindles (23) journalled on the head for rotation relative thereto, and have a source of pressurized lubricant.

Abstract: A rear worm drive shaft (60) for a Davenport® multi-spindle automatic screw machine, comprises: a shaft first part (61) having a portion with a first hardness; a shaft second part (62) having a portion with a second hardness, said second hardness being greater than the first hardness; and a coupling (63) adapted to join the shaft first and second parts in an axially-aligned relation and to prevent relative rotation therebetween. The improved shaft may be changed on a Davenport® screw machine is about one-half hour.

Abstract: An improved spindle assembly (23) is adapted to be mounted in an opening (22) provided on a rotatable head (20) of a multi-spindle machine tool. The improved spindle assembly includes a tubular main spindle part (26) that is adapted to be inserted into the head opening and having a first abutment surface (42), a bearing retainer (27) adapted to be threaded into engagement with the head and having a second abutment surface (55) arranged to face toward the first abutment surface, at least one bearing (28) positioned radially between the head and spindle main part, and being arranged axially between the first and second abutment surfaces, and a retaining nut (29) adapted to be threaded into engagement with the spindle main part so as to form therewith an assembled spindle.

Abstract: An improved spindle assembly (23) is adapted to be mounted in an opening (22) provided on a rotatable head (20) of a multi-spindle machine tool. The improved spindle assembly includes a tubular main spindle part (26) that is adapted to be inserted into the head opening and having a first abutment surface (42), a bearing retainer (27) adapted to be threaded into engagement with the head and having a second abutment surface (55) arranged to face toward the first abutment surface, at least one bearing (28) positioned radially between the head and spindle main part, and being arranged axially between the first and second abutment surfaces, and a retaining nut (29) adapted to be threaded into engagement with the spindle main part so as to form therewith an assembled spindle.

Abstract: The spindle supporting head of a multiple spindle screw machine is intermittently rotated to place its spindles into successively different angular positions about the axis of a spindle drive shaft which extends coaxially into the center of the head. When each spindle is rotatably indexed into a particular angular position, a piece of bar stock is fed through the spindle and projects beyond one end thereof. Each of a plurality of tool slides, which are mounted adjacent the end of the head from which the spindle projects, carries a tool which registers with the stock projecting from an adjacent spindle. The slides are connected to servo motors which are operable by an associated computer to move their tools toward and away from the stock projecting from the associated spindles. Normally the head is secured against rotation by a hirth ring which intermittently is moved from its locking position to release the head so that it can be rotatably indexed.