Receiving arrangement for a multiple type carrier for an impact printer

In apparatus for releasably holding a print wheel provided with a plurality of elastic spokes carrying print type faces in an impact printer having a printing hammer mechanism arranged to act on the type faces and a rotatable setting shaft to which the print wheel can be releasably fastened, which apparatus includes a cassette carrying the print wheel, the cassette being insertable into, and removable from, the printer together with the print wheel, the cassette being provided with guide members, and cassette holding means carried by the printer and defining an insertion shaft extending substantially transversely to the axis of the setting shaft and arranged to cooperate with the guide members to guide the cassette during insertion into the printer, the improvement wherein:

• said cassette holding means comprise detent means;
• said cassette is provided with counterdetent means positioned to engage said detent means to hold said cassette in a fully inserted position in which the print wheel is fastened to the setting shaft;
• said cassette holding means further comprise ejection spring means arranged to move said cassette away from said fully inserted position upon disengagement of said detent means from said counter detent means;
• said detent means comprise at least one pivotal control level carrying a detent tongue engageable with said counterdetent means;
• said cassette presents control means located to act on said level to pivot it into a position for causing said tongue to engage said counterdetent means when said cassette moves into its fully inserted position;
• said ejection spring means produces a force opposing movement of said cassette into its fully inserted position;
• and said cassette holding means further comprise a blocking device disposed for blocking said lever in said position in which said tongue engages said counterdetent means, and a release member in the form of a handle connected to act on said blocking device and manually movable in a direction for moving said blocking device into a position in which said tongue disengages from said counterdetent means.

A receiving arrangement for holding a print wheel provided with a plurality of elastic spokes carrying print type faces in an impact printer having a rotatable setting shaft to which the print wheel can be releasably fastened for rotation with the shaft, said receiving arrangement comprising:

• a cassette formed to enclose the print wheel while leaving exposed the immediate region of the type face with which a printing operation is to be performed;
• arresting means supported by, and movable relative to, said cassette, between a normal position in which said arresting means engage the print wheel to cause the print wheel to be held in a predetermined angular position relative to said cassette, and a release position in which rotation of the print wheel by the shaft is permitted, said arresting means including at least one supporting element formed to cooperate with the print wheel, when said arresting means are in their normal position, in such a manner as to apply to the print wheel a positive arresting force which holds the print wheel in its predetermined angular position and which responds to any tendency of the print wheel to rotate out of the predetermined angular position in a manner to return the print wheel to that angular position, said arresting means being maintained in their normal position when the print wheel is disconnected from the rotatable shaft;
• and guide means carried by said cassette for holding said cassette in position in the printer when the print wheel is fastened to the setting shaft.

In combination including a print wheel provided with a plurality of elastic spokes carrying print type faces and a cassette carrying the print wheel for removably mounting the print wheel in an impact printer having a rotatable setting shaft to which the print wheel can be releasably fastened for rotation with the shaft, the improvement wherein:

• said cassette and said print wheel are provided with cooperating means for positively holding said print wheel in said cassette when said wheel is disconnected from the shaft;
• said cassette comprises means for holding said cassette in position in the printer when the print wheel is fastened to the setting shaft;
• said means for holding comprise a protrusion formed integrally with said print wheel and an opening formed in said cassette to receive said protrusion while permitting said print wheel to have bearing play relative to said cassette for enabling said cassette to be held in position in the printer independently of the position of said print wheel when fastened to the setting shaft;
• and said print wheel comprises positioning means, and further comprising arresting means supported by, and movable relative to, said cassette, between a normal position in which said arresting means engage said print wheel positioning means to hold said print wheel in a predetermined angular position relative to said cassette, and a release position in which rotation of said print wheel by the shaft is permitted, said arresting means including at least one supporting element formed to cooperate with said print wheel positioning means, when said arresting means are in their normal position, in such a manner as to apply to said print wheel a positive arresting force which holds said print wheel in its predetermined angular position and which responds to any tendency of said print wheel to rotate out of the predetermined angular position in a manner to return said print wheel to that angular position, said arresting means being maintained in their noraml position when said print wheel is disconnected from the rotatable shaft.