Collapsible restraint for measuring tapes
AssigneeThe United States of America as represented by the Secretary of the Army
InventorHerbert T. Ueda
Life of this patent
Estimating the term…
Abstract
A collapsible restraint is provided for attachment to the end of a flexible easuring tape in order to allow the thickness of a material, such as an ice layer covering a lake or other body of water, to be measured through a hole in the material. The collapsible restraint includes first and second pivotally connected blades which are maintained in a fully extended position by a locking arrangement to allow the blades to engage the bottom opening of the hole. The locking arrangement can be disabled by an upward pull on the flexible measuring tape in order to cause the blades to pivot to a collapsed position, thereby permitting the restraint to be withdrawn from the hole.
Claims20
A collapsible restraint for attachment to the end of a flexible measuring tape, comprising:
- (a) first and second elongated blades, one end of said first blade being pivotally connected to one end of said second blade such that said first and second blades may be pivoted from a fully extended position in which said blades are in opposed 180.degree. alignment with each other on either side of said pivotal connection to a collapsed position in which the blades form an angle of less than 180.degree. relative to each other;
- (b) locking means for locking said first and second blades in the fully extended position, said locking means being disabled in response to a force applied at a point near the pivotally connected ends of said first and second blades to allow said blades to pivot from the fully extended position to a collapsed position, said locking means comprising:
- (1) a cam surface formed on the end of the first blade which is pivotally connected to the second blade;
- and
- (2) a resilient arm extending along the second blade and terminating at the end of said second blade which is pivotally connected to said first blade, said resilient arm having a free end portion which is urged into contact with and deflected by the cam surface formed on the end of the first blade as the first and second blades are pivoted relative to each other;
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- (c) attachment means for attaching the end of a flexible measuring tape to at least one of said first and second blades at a point near the pivotally connected ends of said first and second blades.
In an apparatus for measuring the thickness of ice and other materials, said apparatus including a flexible measuring tape adapted to be lowered through a hole in the material and an elongated restraining device attached to one end of the measuring tape for engaging the bottom opening of the hole, the improved restraining device which comprises:
- (a) first and second elongated blades;
- (b) means providing a pivotal connection between one end of said first blade and one end of said second blade;
- (c) locking means for locking said first and second blades in a fully extended position in which the blades are in opposed and substantially non-coincident alignment with each other on either side of said pivotal connection so as to lie substantially along a straight line having said pivotal connection at an intermediate point thereon, said locking means being disabled in response to an upward force applied at a point near said pivotal connection to allow said first and second blades to pivot relative to each other from the fully extended position to a collapsed position in which said first and second blades do not lie along a straight line;
- and
- (d) attachment means for attaching the end of said flexible measuring tape to at least one of said first and second blades at a point near said pivotal connection, whereby a tension force may be applied through said measuring tape to disable said locking means and to cause said first and second blades to pivot relative to each other from the fully extended position to a collapsed position.
An apparatus for measuring the thickness of ice and other materials comprising a flexible measuring tape adapted to be lowered through a hole in the material and an elongated restraining device attached to one end of said flexible measuring tape, said restraining device comprising first and second blades pivotally connected to each other near the ends thereof, said first blade having a cam surface formed thereon and said second blade including resilient means thereon which is urged into contact with and deflected by said cam surface when the blades are pivoted relative to each other, said cam surface and said resilient means acting to provide resistance to pivoting movement between said first and second blades when said blades are in a mutual fully extended position, at least one of said first and second blades being attached to the end of said flexible measuring tape at a point near the pivotal connection between said first and second blades, whereby said first and second blades may be pivoted relative to each other from the mutual fully extended position to a collapsed position in response to a tension force applied through said flexible measuring tape, said force being sufficient to overcome the resistance provided by said cam surface and said resilient means to the pivoting movement between said first and second blades.
Dependencies are inferred from the claim text.