Inside corner concrete form unit

A concrete form unit for inside corner casting comprises:

• a pair of form panels disposed generally perpendicular to each other;
• an elongated corner member disposed generally between adjoining edges of said panels;
• actuator means having relatively moveable first and second parts interconnecting said panels and said corner member, said second part being connected to move said corner member;
• parallelogram linkage means connecting each of said form panels to said first part of said actuator, said linkage means having respective collapsed and expanded conditions;
• holding means having a retaining condition operable to cooperate between said corner member and said form panels to retain said corner member against displacement toward said panels while said linkage means is shifted to said expanded condition by said actuator to strip said panels from the hardened concrete, said holding means including distance rod means engageable between said corner member and at least one of said form panels to retain said corner member;
• latch means having a holding condition operable to hold said form panels against relative movement while said actuator strips said corner member, said latch means including a shiftable latch cooperable with said linkage means in said holding condition of said latch means to hold such form panels against relative movement, said latch being pivotally mounted to engage within a notch formed in one link of said linkage means and hold said linkage means in said expanded condition;
• and
• operating means effective to operate said holding means to and from said retaining condition and operate said latch means to and from said holding condition.

A concrete from unit for inside corner casting comprises:

• a pair of form panels disposed generally perpendicular to each other;
• an elongated corner member disposed generally between adjoining edges of said panels;
• actuator means having relatively moveable first and second parts interconnecting said panels and said corner member, said second part being connected to move said corner member;
• parallelogram linkage means connecting each of said form panels to said first part of said actuator, said linkage means having respective collapsed and expanded conditions;
• holding means having a retaining condition operable to cooperate between said corner member and said form panels to retain said corner member against displacement toward said panels while said linkage means is shifted to said expanded condition by said actuator to strip said panels from the hardened concrete, said holding means including distance rod means engageable between said corner member and at least one of said form panels to retain said corner member;
• latch means having a holding condition operable to hold said form panels against relative movement while said actuator strips said corner member, said latch means including a shiftable latch cooperable with said linkage means in said holding condition of said latch means to hold said form panels against relative movement;
• and
• operating means effective to operate said holding means to and from said retaining condition and operate said latch means to and from said holding condition, said operating means including an axially extensible operator and an operating rod extending longitudinally of said form panels and said corner member coupled to be reciprocated by said operator, said operating rod being connected to both said distance rod means and said shiftable latch to effect their operation.