Abstract: A solenoid-operated valve has its body formed from a plain length of pipe substantially free of any machining or shoulders. The armature and seating are inside, with the armature moving axially, and the solenoid coil is slid over the outside of the pipe. There could be a by-pass and two valves, one with a by-pass and one without, could be mounted in series in a common length of pipe.

Abstract: A component having an externally engaged actuating member which effects an internal change at what is required to be a closely repeatable position in the movement of the member, e.g. a micro-switch actuated by a push button, is calibrated by progressively moving the actuating member while sensing for the internal change then, when the change occurs, clamping the actuating member (e.g. the push button) and cutting it to length.

Abstract: A key rotatably supported in a mounting and capable of being brought into engagement with a lock is held in the correct orientation for engaging the lock by being locked to the mounting by a retractable sleeve. Only when the mounting is brought into engagement with the lock does a portion of the lock engage the sleeve and push it back relative to the mounting to free the key for rotation. The mounting may be on a moveable part of a machine guard with the lock on a fixed part and controlling operation of the machine.

Abstract: A micro-switch has an auxiliary return spring in the form of a hairpin spring acting directly on the actuating button through a hole in the contact carrier to increase the return force on whatever external means engage the button, but without affecting the behavior of the contact carrier. The use of a hairpin spring allows it to be accommodated within an existing standard switch body without upsetting the placing of standard mounting holes.

Abstract: A snap-action micro-switch of a known general kind has an auxiliary spring that acts on the actuating member in the operating direction but has a force characteristic that falls with displacemet away from the rest position. The effect of this is to reduce the required externally applied actuating force but without reducing the contact pressure applied by the normal snap-action spring.

Abstract: Microswitches customarily have a casing assembly housing the switching mechanism, and an actuating button projecting from the casing. For some applications it is desirable to provide a pivotally mounted lever for depressing the button. Such lever has usually been secured in assembly of the casing.To enable levers to be added as required to stocks of assembled switches, the lever 4 is pivotally mounted on a mounting block 5 which can be snap-fitted to the assembled casing 2 of a switch as required. The block comprises a spigot 6 which is received in a socket in the casing. Oppositely-facing knife-edges 10, 12 of the lever engage bearing faces 9, 11 of the block. A key-hole slot 13 allows the lever to be passed over a post 8 of the block, projecting head portions 14 of the post 8 retaining the lever after assembly with the block.

Abstract: A key-operated device, for example for controlling access to switch gear or potentially dangerous machinery, has a rotary motion with an axially inserted key but departs from the usual barrel lock construction which is sensitive to foreign matter. Instead it has a faceplate in front of a stationary body with a cylindrical member rotatable in it and having a recess for the key and circumferentially spaced notches in a flange close behind the plate and prevented from direct access through the keyhole by a fixed axially extending wall on the back of the plate but accessible by appropriate lugs on the key when the latter is inserted. The rotatable member is connected through a spindle to a switch, valve or latch or other actuated device.

Abstract: A method and device for rendering safe the opening or removal of a machine door which is normally kept locked to guard machinery or an area which is potentially hazardous. The device includes a lock unit having a lock body for connection to the frame panel of machinery to be guarded and supports an electrical switch. A key unit includes a key body which supports a rotatable control knob and a key adapted to cooperate with the lock body when the door is closed on the frame panel. The key body includes a radially extending peripheral flange formed with a hole towards its outer edge which rotatably receives the head of a screw. The threaded end of the screw cooperates with a threaded hole in the frame panel when the door is closed and must be screwed fully into the hole to fully close the door onto the panel.

Abstract: A micro-switch having an actuating mechanism comprising a slide member which is movable longitudinally of itself in the switch casing and engages the electrical switching element, and a pivoted actuator which extends externally of the switch casing and comprises a length of wire which is pivoted in a hole in the switch casing and which has a bent end portion within the casing which is connected to the slide member so that pivoting of the actuator in one particular sense causes the slide member to move longitudinally to operate the switching element. Preferably, said end portion of the wire is connected to the inner end of the slide member by engaging an aperture or recess in the latter. The recess is conveniently a transverse channel formed in the side face of the slide member which is exposed on removal of a switch cover. That portion of the wire projecting from the other side of the casing can be bent through 90.degree.