Patent GB-1217938-A (GB)
Title: Safety harness device
Inventor: GLAUSER JAMES ERNEST
IPC: B60R22/41
Filed: 1968-08-06
Abstract: 1,217,938. Safety harness. PACIFIC SCIENTIFIC CO. 6 Aug., 1968 [15 Aug., 1967], No. 37555/68. Heading A3V. A safety harness device comprises a frame member 1 on which is mounted a rotatable spool 6 fixed on a spindle 4 connected to a rewind spring 12 fastened to the frame 1 and tending to wind in a seat belt strap 8, an inertia member 21 carried on an end portion of the spindle 4 rotatable about an axis parallel to but separate from that of the spindle, a cup member 27 rotatably carried by the spindle 4 and having gripping portions 29 co-operating with portions 29<SP>1</SP> on inertia member 21 which portions are normally held out of engagement by a calibration spring 24, a lock bar 37 pivotably supported on the frame 1 and having teeth 39, 39<SP>1</SP> co-operating with 40, 40<SP>1</SP> on the spool 6 but normally held apart by a spring means 41 connected to the cup member 27 whereby when the pay out rate of the strap 8 exceeds a value predetermined by the tension of the calibration spring 24 the inertia member 21 turns against the tension of the calibration spring 24 and causes the gripping portions 29, 29<SP>1</SP> to engage with those on the cup member 27 and cause it to turn and overcome the force of the spring means 41 thus making the lock bar 37 turn so that its teeth 39, 39<SP>1</SP> engage the teeth 40, 40<SP>1</SP> on the spool, thus locking it. The hub of the spool 6 is C-shaped with a gap between it and the spindle 4 to allow the strap 8 to be wound on it and the spindle is retained in position by means of a U-shaped bowed spring member 15. A circular flange member 19 fits a step 18 on the end of the spindle and carries the inertia member 21 mounted rotatably on a boss 20. Calibration spring 24 holds the inertia member 21 to a stop pin (23), Fig. 6 (not shown), and possible rotation of the inertia member is limited by a further stop pin (22). Cup member 27 turnably mounted on the hub of flange 19 is provided on its inner cylindrical surface with ratchet teeth 29 for co-operating with a pair of similar teeth 29<SP>1</SP> on the inertia member 21. A clutch spring 30, resiliently gripping the peripheral surface of the cup member 27 with a definite pressure, has a bifurcated lug 33 projecting from it which engages the bent over tongue 34 of a lever 35 attached to a spring extension 41 trying to turn clock-wise the locking bar 37 the end of which is fitted in a slot of the lever 35. When the strap is being pulled out in normal use the spring 12 allows the reel 5 to unwind but in the event of excessive acceleration of the reel, inertia member 21 will turn with respect to its boss 20 so that its teeth 29<SP>1</SP> will engage the teeth 29 on the cup member making the latter turn with the reel so that the lug 33 on the clutch turns the lock bar causing the teeth 39, 39<SP>1</SP> to engage in the teeth 40, 40<SP>1</SP> of the reel. Should the teeth 39, 39<SP>1</SP> in moving to the locked position engage the tops of teeth 40, 40<SP>1</SP> so as to lock instantly the clutch spring 30 slides momentarily over the flange member 19 and enable the lock bar teeth 39, 39<SP>1</SP> to hesitate and then engage the succeeding teeth 40, 40<SP>1</SP>. To prevent the device from jamming and thus pulling the belt out across the body the cover 52 is provided with a central threaded stud 43 on which a nut 44 rides. This nut has apertures for receiving projecting end portions stop pins (22), Fig. 4 (not shown), and (23) so that the nut turns with the reel spindle 4 and hence threads itself along the stud 43 in use. The nut 44 is so positioned on the stud 43 that a bevelled boss (45) thereon will substantially abut the edge of the inertia member 21 during the initial pull out of the strap thus preventing turning of this inertia member on its supporting boss 20 and hence preventing locking of the reel. After the strap has passed across the user's body the boss (45) on the nut 44 will have travelled sufficiently towards the outer end of the cup 42 to clear the inertia member 21 permitting this member to operate to effect locking of the device whenever necessary. In an alternative arrangement (Fig. 10, not shown) the clutch spring 30 and the biasing spring lever 35 are eliminated and instead there is a lock bar retraction spring (47) and an activator spring (48). When a locking action takes place turning of the cup member 27 due to the action of the inertia member 21 will cause the activator spring (48) to stretch overcoming the tension of the retraction spring (47) and causing the bar 37 to lock.