Polarized deceleration brake for self retracting device
An apparatus and an associated method relates to a directionally polarized deceleration module (PDM) include a shuttle ( 125 ) fixedly coupled to a spring-biased spool ( 120 ) rotatable coupled to a module housing ( 115 ), a dynamic braking member (DBM) ( 130 ) and the shuttle ( 125 ) configured to travel inside a channel anchored to the module housing ( 115 ). A tether may be anchored on a proximal end to the spool ( 120 ). As the tether is retracted, the DBM ( 130 ) may be pushed by an angled distal-end of the shuttle ( 125 ). The DBM ( 130 ) may be forced between the angled distal-end of the shuttle ( 125 ) and an inner channel wall, providing motional resistance to the tether. As the tether is extracted, the DBM ( 130 ) may be pushed substantially normal to a proximal-end of the shuttle ( 125 ), providing minimal motional resistance to the tether. Various PDMs may decelerate safety lanyards in one direction to substantially avoid tangling and/or damage.
1. A polarized deceleration apparatus for use in a self-retracting device (SRD) in personal protection applications, the polarized deceleration apparatus comprising:
a cylindrical drum rotatably coupled to a housing, the cylindrical drum rotatable about a longitudinal axis so as to unspool a tether in an extraction mode and to spool the tether in a retraction mode;
a circular channel fixedly coupled to the housing and disposed in a plane orthogonal to the longitudinal axis, wherein the circular channel is ring-shaped and has an inner wall and an outer wall;
a shuttle mechanically coupled to the cylindrical drum, the shuttle configured to move within the confines of the inner wall and the outer wall of the ring-shaped circular channel when the cylindrical drum rotates; and
a dynamic braking member (DBM) configured to move within the confines of the inner wall and the outer wall of the ring-shaped circular channel;
wherein the shuttle further comprises a retraction face configured to guide the DBM into a frictional retraction impingement with an inside surface of the circular channel when the cylindrical drum is in the retraction mode, and
wherein the shuttle further comprises an extraction face configured to guide the DBM around the circular channel when the cylindrical drum is in an extraction mode.
2. The polarized deceleration apparatus of claim 1 , wherein the extraction face of the shuttle is substantially parallel with a radius of the circular channel.
3. The polarized deceleration apparatus of claim 1 , wherein the retraction face of the shuttle comprises a substantially linear slope.
4. The polarized deceleration apparatus of claim 1 , wherein the retraction face of the shuttle is concave.
5. The polarized deceleration apparatus of claim 1 , wherein the retraction face of the shuttle is convex.
6. The polarized deceleration apparatus of claim 1 , wherein the retraction face of the shuttle is hyperbolic.
7. The polarized deceleration apparatus of claim 1 , wherein the retraction face of the shuttle is piecewise linear.
8. The polarized deceleration apparatus of claim 1 , wherein the retraction face of the shuttle is complementary to at least one face of the DBM.
9. The polarized deceleration apparatus of claim 1 , wherein the DBM is substantially cylindrical.
10. The polarized deceleration apparatus of claim 1 , wherein a frictional extraction force associated with the extraction mode is less than a frictional retraction force associated with the retraction mode.
11. A polarized deceleration apparatus for use in a self-retracting device (SRD) in personal protection applications, the polarized deceleration apparatus comprising:
a cylindrical drum rotatably coupled to a housing, the cylindrical drum rotatable about a longitudinal axis so as to unspool a tether in an extraction mode and to spool the tether in a retraction mode;
a circular channel fixedly coupled to the housing and disposed in a plane orthogonal to the longitudinal axis, wherein the circular channel is ring-shaped and has an inner wall and an outer wall;
a shuttle mechanically coupled to rotate in response to the cylindrical drum, the shuttle configured to move within the confines of the inner wall and the outer wall of the ring-shaped circular channel when the cylindrical drum rotates; and
a dynamic braking member (DBM) configured to move within the confines of the inner wall and the outer wall of the ring-shaped circular channel,
wherein the shuttle further comprises a retraction face configured to guide the DBM into a frictional retraction impingement with an inside surface of the circular channel when the cylindrical drum is in the retraction mode.
12. The polarized deceleration apparatus of claim 11 , wherein the retraction face of the shuttle comprises a substantially linear slope.
13. The polarized deceleration apparatus of claim 11 , wherein the retraction face of the shuttle is concave.
14. The polarized deceleration apparatus of claim 11 , wherein the retraction face of the shuttle is complementary to at least one face of the DBM.
15. The polarized deceleration apparatus of claim 11 , wherein the DBM is substantially cylindrical.
16. The polarized deceleration apparatus of claim 11 , wherein the shuttle further comprises an extraction face, wherein in the extraction mode, the extraction face of the shuttle is configured to guide the DBM around the circular channel, and wherein a frictional extraction force associated with the extraction mode is less than a frictional retraction force associated with the retraction mode.
17. A polarized deceleration apparatus for use in a self-retracting device (SRD) in personal protection applications, the polarized deceleration apparatus comprising:
a cylindrical drum rotatably coupled to a housing, the cylindrical drum rotatable about a longitudinal axis so as to unspool a tether in an extraction mode and to spool the tether in a retraction mode;
a circular channel fixedly coupled to the housing and disposed in a plane orthogonal to the longitudinal axis, wherein the circular channel is ring-shaped and has an inner wall and an outer wall;
a shuttle mechanically coupled to rotate in response to the cylindrical drum, the shuttle configured to move within the confines of the inner wall and the outer wall of the ring-shaped circular channel when the cylindrical drum rotates; and
a dynamic braking member (DBM) configured to move within the confines of the inner wall and the outer wall of the ring-shaped circular channel,
wherein the shuttle further comprises means for guiding the DBM into a frictional retraction impingement with an inside surface of the circular channel when the cylindrical drum is in the retraction mode.
18. The polarized deceleration apparatus of claim 17 , wherein the shuttle further comprises an extraction face substantially parallel with a radius of the circular channel.
19. The polarized deceleration apparatus of claim 17 , wherein the DBM is substantially cylindrical.
20. The polarized deceleration apparatus of claim 17 , wherein the shuttle further comprises an extraction face, wherein in the extraction mode, the extraction face of the shuttle is configured to guide the DBM around the circular channel, and wherein a frictional extraction force associated with the extraction mode is less than a frictional retraction force associated with the retraction mode.