Tape rule with resilient lock
One aspect of an invention disclosed herein relates to improved durability of the thumb engaging portion of a tape rule locking assembly. In accordance with this aspect, there is provided a retractable rule assembly comprising a housing assembly; a reel rotatably mounted in the housing assembly; and an elongated blade formed of a ribbon of metal being wound on the reel. The elongated blade has measuring indicia formed on a concave side thereof; and a coil spring formed of a ribbon of metal is constructed to rotate the reel in the housing assembly in a direction to wind up the elongated blade. A blade holding assembly for holding the blade in a position of extension outwardly of said housing, said blade holding assembly comprising a resilient thumb engaging portion and a receiving region behind the thumb engaging portion to enable the thumb engaging portion to deform into the receiving region to absorb impact.
1. A retractable rule assembly, comprising:
a housing assembly;
a reel rotatably mounted in said housing assembly;
an elongated blade formed of a ribbon of metal being wound on the reel, said elongated blade having measuring indicia formed on a concave side thereof;
a coil spring formed of a ribbon of metal constructed to rotate said reel in said housing assembly in a direction to wind up the elongated blade; and
a blade holding assembly for holding the blade in a position of extension outwardly of said housing, said blade holding assembly comprising a resilient thumb engaging portion and a receiving region behind the thumb engaging portion to enable the thumb engaging portion to deform into the receiving region to absorb impact.
2. A retractable rule assembly according to claim 1 , wherein the resilient thumb engaging portion comprises an elastomeric material, and the receiving region comprises a void.
3. A retractable rule assembly according to claim 2 , wherein the blade holding assembly further comprises a body portion comprising a plastic material, the body portion being joined to the thumb engaging portion.
4. A retractable rule assembly according to claim 3 , wherein the body portion comprises an arcuate portion terminating in a free end for engaging the blade.
5. A retractable rule assembly according to claim 4 , wherein the body portion further comprises an outwardly extending portion and a mounting portion, the thumb engaging portion being mounted on the mounting portion.
6. A retractable rule assembly according to claim 1 , wherein the resilient thumb engaging portion is fastened to the blade holding assembly by a chemical or adhesive bond.
7. A retractable rule assembly according to claim 1 , wherein the resilient thumb engaging portion comprises an elastomeric material, and the receiving region comprises a material of a lower durometer than a durometer of the thumb engaging portion.
8. A retractable rule assembly according to claim 1 , wherein the resilient thumb engaging portion is fastened to the blade holding assembly by a mechanical bond.
9. A retractable rule assembly according to claim 1 , wherein the thumb engaging portion deforms a distance that is greater than 50% of the cross-sectional thickness thereof, wherein the thickness is measured at a region of maximum cross-sectional thickness at a region of the thumb engaging portion that deforms towards the receiving region.
10. A blade locking structure for a rule assembly, comprising:
a generally arcuate body portion comprising a plastic material; and
a thumb engaging portion joined with said body portion, said thumb engaging portion comprising an elastomeric material, and a receiving region behind the thumb engaging portion to enable the thumb engaging portion to deform into the receiving region to absorb impact upon the thumb engaging region.
11. A blade locking structure according to claim 10 , wherein the receiving region is between the thumb engaging portion and the plastic material.
12. A blade locking structure according to claim 11 , wherein the receiving region is entirely within the elastomeric material of the thumb engaging portion.
13. A blade locking structure according to claim 11 , wherein the receiving region is in direct communication with the plastic material.
14. A blade locking structure according to claim 11 , wherein the receiving region is filled with a lower durometer material in comparison with a durometer of the thumb engaging portion.
15. A blade locking structure according to claim 11 , wherein a material forming the receiving region is of a different color than that of the thumb engaging portion.
16. A blade locking structure according to claim 11 , wherein the receiving region comprises a cellular structure.
17. A blade locking structure according to claim 16 , wherein the cellular structure is comprised of a different material than that of the thumb engaging portion.
18. A blade locking structure according to claim 10 , wherein the receiving region is a void.
19. A blade locking structure according to claim 18 , wherein the void is a thru void.
20. A blade locking structure according to claim 10 , wherein the receiving region comprises a plurality of voids.
21. A blade locking structure according to claim 10 , wherein an exterior surface portion of the thumb engaging portion is perforated.
22. A blade locking structure according to claim 10 , wherein an exterior surface portion of the thumb engaging portion has recessed grooves.
23. A blade locking structure according to claim 10 , wherein an exterior surface portion of the thumb engaging portion has a plurality of protrusions.
24. A blade locking structure according to claim 10 , wherein an exterior surface portion of the thumb engaging portion has a combination of protruding and recessed grooves.
25. A blade locking structure according to claim 10 , wherein the thumb engaging portion has a non-constant cross-sectional thickness.
26. A blade locking structure according to claim 10 , wherein the thumb engaging portion deforms a distance that is greater than 50% of the cross-sectional thickness thereof, wherein the thickness is measured at a region of maximum cross-sectional thickness at a region of the thumb engaging portion that deforms towards the receiving region.
27. A retractable rule assembly, comprising:
a housing assembly;
a reel rotatably mounted in said housing assembly;
an elongated blade formed of metal being wound on the reel, said elongated blade having measuring indicia formed on a concave side thereof;
a coil spring formed of metal constructed to rotate said reel in said housing assembly in a direction to wind up the elongated blade; and
a blade holding assembly for holding the blade in a position of extension outwardly of said housing, said blade holding assembly comprising a thumb engaging portion and a blade engaging portion, said blade engaging portion comprising a resilient structure at a free end thereof for engaging the blade, wherein the resilient structure comprises a resilient outer material and a receiving region behind the resilient outer material, the resilient outer material being deformable into the receiving region.
28. A retractable rule assembly according to claim 27 , wherein the receiving region comprises a void.
29. A retractable rule assembly according to claim 27 , wherein the receiving region comprises a material of a lower durometer than the resilient outer material.
30. A retractable rule assembly according to claim 27 , wherein the thumb engaging portion deforms a distance that is greater than 50% of the cross-sectional thickness thereof, wherein the thickness is measured at a region of maximum cross-sectional thickness at a region of the thumb engaging portion that deforms towards the receiving region.