Holding and follow-up mechanism for ultrasonic flaw detector

Claim 2

A holding and follow-up mechanism for an ultrasonic flaw detector comprising, a holding arm for mounting the mechanism, a material engaging member, a detector element mounted on said material engaging member for detecting material flaws, a four linked mechanism comprising two pairs of substantially parallel links spaced laterally on and pivotally connected at one end to said material engaging member and at the other end to said holding arm, at least one link of said four linked mechanism forming one arm of a bell crank with the pivot point of the bell crank being one of the pivotal connections to said holding arm, the other arm of said bell crank extending therefrom, a double acting cylinder having a piston with a projecting arm and being responsive to differential pressure to extend and retract said projecting arm, and connecting means between said projecting arm and the remote end of said other arM of said bell crank for moving said material engaging member into and out of a material engaging position with extension and retraction of said projecting arm.

Claim 3

A holding and follow-up mechanism as defined in claim 1 wherein one of said links is pivotally connected to said material engaging member with a pin and slot connection, thereby providing for pivotal movement and limited linear movement of said material engaging member.

Claim 4

A holding and follow-up mechanism as defined in claim 2 wherein said one of said links has said slot formed therein, said slot being pivotally engaged with said pin extending from said material engaging member.

Claim 5

A holding and follow-up mechanism as defined in claim 1 wherein said connecting means includes an elastically yieldable means to accommodate limited movement of said material engaging member.

Claim 6

A holding and follow-up mechanism as defined in claim 1 which further comprises a switch responsive to the presence of a material to be tested to operate a valve for controlling the pressure applied to said double acting cylinder.

Claim 7

A holding and follow-up mechanism as defined in claim 5 wherein said switch responsive to the presence of a material to be tested comprises a photocell switch to detect the presence or absence of material to be tested.

Claim 8

A holding and follow-up mechanism for an ultrasonic flaw detector comprising, a holding arm for mounting the mechanism, a supporting shoe for engaging a material to be tested, a detector element mounted on said shoe for detecting flaws in the material to be tested, a pair of bell cranks each having a first and second arm and a pivot point at the junction of said first and second arms, a pair of link members, the remote end of said first arm of each bell crank being pivotally connected with said shoe on opposite sides thereof and said pivot point being pivotally connected to said holding arm, said link members being pivotally connected at one end to opposite sides of said shoe spaced from said remote end of said first arm and being pivotally connected at the other end to said holding arm, said first arm and said link member on each side being substantially parallel to one another, a double acting cylinder having a piston with a projecting arm and being responsive to differential air pressure to extend and retract said projecting arm, means connecting said projecting arm to the remote ends of said second arms of said bell cranks for moving said shoe into and out of engagement with said material to be tested in response to extension and retraction of said projecting arm.

Claim 9

A holding and follow-up mechanism for an ultrasonic flaw detector comprising, a holding arm for mounting the mechanism, a supporting shoe for engaging a material to be tested, a detector element mounted on said shoe for detecting flaws in the material to be tested, a pair of bell cranks each having a first and second arm and a pivot point at the junction of said first and second arms, a pair of link members, the remote end of said first arm of each bell crank being pivotally connected with said shoe on opposite sides thereof and said pivot point being pivotally connected to said holding arm, said link members being pivotally connected at one end to opposite sides of said shoe spaced from said remote end of said first arm and being pivotally connected at the other end to said holding arm, said first arm and said link member on each side being substantially parallel to one another, a double acting cylinder having a piston with a projecting arm and being responsive to differential air pressure to extend and retract said projecting arm, means connecting said projecting arm to the remote ends of said second arms of said bell cranks for moving said shoe into and out of engagement with said material to be tested in response to extension and retraction of said projecting arm.

Claim 10

A holding and follow-up mechanism as defined in claim 7 in which said means connecting said projecting arm to the remote ends of said second arms includes a spring permitting movement of said bell cranks in response to movements of said shoe as the material to be tested passes beneath and in contact with said shoe.

Claim 11

A holding and follow-up mechanism as defined in claim 7 in which the pivotal connection of one of said link members to said shoe is a pin and slot connection providing pivotal movement and limited linear movement of the shoe in the region of the connection in a direction at right angles to the movement of the material to be tested.