US 4,153,996 A · Coilable rule with combination blade lock and shock absorber mechanism

Abstract

A coilable rule is provided with a combination blade lock and shock absorber mechanism to lock its measuring blade in an extended position and absorb the shock of impact upon retraction of the blade. A lever is attached to the rule housing by a slidable pivot connection which allows the lever to be manually pivoted into and out of engagement with the measuring blade and also permits longitudinal movement of the lever relative to the housing. The lever is normally biased against the measuring blade by a bias spring to lock the blade in any extended position. When the blade is released and retracted under the action of its recoil spring, a blade pull-out hook contacts and moves the lever longitudinally against the bias spring to slide the lever relative to the housing and absorb the shock of impact.

Claims9

Dependent claims

In a coilable rule having a housing, a retractable measuring blade with a free end extending through an opening in the housing, and a hook at the free end of the blade, a combination blade lock and shock absorber, comprising:

a lever mounted on the housing and located adjacent to the opening therein for engagement with the hook to prevent complete retraction of the blade into the housing;
pivot means for pivotally connecting said lever to the housing to allow said lever to be manually pivoted into and out of engagement with the blade, said pivot means forming a lost motion connection to permit both pivotal and longitudinal movement of said lever relative to said housing;
and
spring bias means for normally biasing said lever angularly about said pivot means into engagement with the blade to prevent movement thereof and biasing said lever longitudinally toward said opening for absorbing the shock of impact when the hook engages the lever upon the termination of retraction of the blade into the housing.

1 more element

In a coilable rule having a housing provided with an open bottom end, a coilable measuring blade with a free end extending outwardly from the housing, a spring to retract the blade into the housing, and a hook at the free end of the blade to prevent complete retraction of the blade into the housing, a combination blade lock and shock absorber, comprising:

a lever extending longitudinally across the open bottom end of the housing and having a front end thereof located in the path of the hook and a rear end, said front end of said lever cooperating with the housing to define a mouth for passing the blade;
pivot means for pivotally connecting said lever to the housing to allow said front end to be moved into and out of engagement with the blade by manual pressure at said rear end thereof, said pivot means comprising a lost motion connection to permit a predetermined amount of forward translational movement of said lever relative to the housing;
and
spring bias means for biasing said lever angularly about said pivot means to normally hold said front end in engagement with the blade to prevent movement of the blade and to bias said lever forwardly to absorb the shock of impact when the hook moves into contact with said lever upon retraction of the blade into the housing.

1 more element

Dependencies are inferred from the claim text.

Coilable rule with combination blade lock and shock absorber mechanism

Life of this patent

Coilable rule with combination blade lock and shock absorber mechanism

Life of this patent

Abstract

Claims9