Patents: Improvements relating to Pocket and like Knives
On 11 October 1941, the company of Joseph Rodgers and Sons from Sheffield, and its employee Donald Ashford Palmer, applied for a patent for an ingenioius locking mechanism for a folding knife. The patent was granted under number 549,428.
The locking mechanism operated through a push-button on the side of the handle or bolster. This operated as follows: the blade tang had two holes (15 and 25 in the drawings on the opposite page) diametrically opposite each other on an equal distance of the blade axis. Each of those holes had a plunger body in the form of a ball (24), which was kept in place between the liners.
Just behind the axis of the blade, the bolster had an opening which, when the blade was opened or closed, corresponded with either of the two plunger balls. This opening had a spring loaded locking bolt on the left side of the blade (12), and a releasing pin (17) with an exterior head (18) on the right side. In either the opened or closed position, the spring pushed the locking bolt, ball and releasing pin outwards, thereby blocking the movement of the blade. This is shown (with the blade closed) in figure 2. The outward movement of the releasing pin was limited by a forked retaining plate (20) mounted on the bolster, which engaged a groove in the releasing pin (22).
To unlock the blade, both from the opened or closed position, the exterior head had to be pushed inwards. Its inward movement was limited by its head against the bolster.
Pushing the head, moved the plunger ball back into the center of the blade spine, whereupon the blade was unlocked.
In a slightly modified arrangement, the releasing pin could be mounted without the retaining plate. Details of this construction are not shown in the drawings.
The locking mechanism operated through a push-button on the side of the handle or bolster. This operated as follows: the blade tang had two holes (15 and 25 in the drawings on the opposite page) diametrically opposite each other on an equal distance of the blade axis. Each of those holes had a plunger body in the form of a ball (24), which was kept in place between the liners.
Just behind the axis of the blade, the bolster had an opening which, when the blade was opened or closed, corresponded with either of the two plunger balls. This opening had a spring loaded locking bolt on the left side of the blade (12), and a releasing pin (17) with an exterior head (18) on the right side. In either the opened or closed position, the spring pushed the locking bolt, ball and releasing pin outwards, thereby blocking the movement of the blade. This is shown (with the blade closed) in figure 2. The outward movement of the releasing pin was limited by a forked retaining plate (20) mounted on the bolster, which engaged a groove in the releasing pin (22).
To unlock the blade, both from the opened or closed position, the exterior head had to be pushed inwards. Its inward movement was limited by its head against the bolster.
Pushing the head, moved the plunger ball back into the center of the blade spine, whereupon the blade was unlocked.
In a slightly modified arrangement, the releasing pin could be mounted without the retaining plate. Details of this construction are not shown in the drawings.
The drawings from British Patent 549,428 in the name of Joseph Rodgers and Sons Limited and Donald
Ashford Palmer, both from No. 6 Works, Pond Hill, Sheffield.