Punch retainer
OwnerBernard J. Wallisinventor
Life of this patent
Estimating the term…
Abstract
A punch and retainer assembly wherein the punch has a flattened surface at the upper end of the side wall thereof and a radially inwardly extending recess directly below the flattened side wall portion. The punch retainer includes a vertically movable latch adapted to engage within the recess on the shank of the punch and retain the punch within the retainer block. Means are provided for limiting vertical movement of the latch so that the punch can be inserted into the retainer only when the flattened surface thereof is aligned parallel with the pivot axis of the latch.
Claims16
In combination, a punch having a shank of circular cross section, said shank having a flat side wall portion extending lengthwise of the punch to the upper end thereof, said shank having a radially inwardly extending recess at the lower end of said flat side wall portion, a retainer having a vertically extending circular bore therein sized to receive said shank and abutment means against which the shank is adapted to bottom when the punch is inserted upwardly therein, said retainer also having a socket therein opening at one side thereof into said bore, a latch supported at one end thereof in said socket for pivotal movement about a horizontal axis spaced radially from said bore, the opposite end of said latch being adapted to engage said recess when the upper end of the punch shank is inserted axially into said bore to retain the punch therein, means biasing said latch to pivot downwardly and means in said socket limiting the pivotal movement of said latch in an upward direction to a position wherein the punch-engaging end of the latch just clears the flat side wall portion on the shank of the punch whereby the punch can be inserted into said bore to interengage the latch with the flat side wall portion of the shank only when the punch is oriented with the flat side wall portion aligned parallel with the pivot axis of said latch, the punch engaging end of said latch comprising a generally cylindrical surface extending parallel to the pivot axis of the latch, said recess including a generally flat latch-engaging surface extending downwardly and radially inwardly from the lower end of said flat side wall portion, said latch being inclined upwardly from its pivot axis with its punch-engaging end engaging said flat latch surface in a wedging relation when the punch bottoms against said abutment means.
In combination, a punch having a shank of circular cross section, said shank having a flat side wall portion extending lengthwise of the punch to the upper end thereof, said shank having a radially inwardly extending recess at the lower end of said flat side wall portion, said recess comprising a flat face which is inclined downwardly and radially inwardly, a punch retainer block having a vertically extending circular bore sized to receive said shank with a close fit and also having abutment means therein against which the upper end of the shank is adapted to bottom when the punch is inserted upwardly into said bore, said retainer also having a socket therein offset radially from said bore and opening at one side thereof into said bore, said socket having at least one flat side wall at the radially outer side thereof disposed radially opposite the flat face on the shank when the punch bottoms against said abutment means, a punch latch in said recess having diametrically opposed cylindrical contact surfaces, means in said socket biasing said latch downwardly to a position wherein one of said cylindrical contact surfaces is engaged in tangential line contact with the flat side wall of the socket and the other is in tangential line contact with the flat face on the punch shank in wedging relation thereto when the upper end of the punch bottoms against said abutment means, means in said socket limiting upward movement of the latch to a position wherein the punch engaging contact surface of the latch just clears the flat side wall portion of the punch whereby the punch can be inserted into said bore to interengage the latch with the inclined face of the shank recess only when the punch is oriented with its flat side wall portion aligned parallel with the axis of the cylindrical contact surface of the latch, said latch and said inclined flat face of said recess being arranged such that when the upper end of the punch bottoms against said abutment means a line through the latch perpendicular to the tangential line of contact between the latch and the punch is inclined upwardly in a radially inward direction.
Dependencies are inferred from the claim text.