More info from our CPF member EdTor about LA Screw Products flashlights:
Some corrections and additions:
1. I wrote "The one exception to all 'D' sized lights was a 2 cell (and I think a 3 cell) 'C' sized baton & light." I should have wrote; The one exception to all 'D' sized lights was a limited 'C' sized light family which included a 2 cell 'C' sized light made as the handle of a 'standard' police baton & ALSO what they called their "Back Up Light." Their Back Up Light was made, initially anyway, in 2, 3, 5, and 7 'C' cell models and all had a leather lanyard at the tailcap as standard. The switch was also in the tailcap. Again, these were the same small diameter end to end so L.A. Screw cut down the reflector to near nothing which produced a horrible light output. Maybe that's why they slipped my mind -- they really had next to no market.
2. I also forgot to mention that L.A. Screw had a blue anodized light in their 'D' line-up called the Power Probe. It was the same as the black Code Four except blue for non-law enforcement markets.
3. I also wrongly implied you could turn off a switchless Code Four by "just backing one section off by 'a hair'" True, but that "one section" has to be the head, not the facecap but the head. That's because you are backing off from the Shock Plate Assembly (also called the Contact Plate) and its little contacts at the outer edge that transfer ground to the base of the bulb.
1. When I wrote previously my mind was influenced by the fact that Mag does this differently and by loosening its tailcap would kill the light. Not so with Code Four. This is because Mag chose to machine their threads first THEN anodize (which is an insulator) and that required them to machine off the anodizing from the face (butt?) of their barrels and mating surface on their endcap in what is called a 'second operation.'. Most Mag owners learn quickly that the tailcap MUST be tight or no light. Alternately, L.A. Screw anodized first THEN machined their threads in a second operation. That made the entire surface area of the threads electrically conductive. This also allowed the use of those flat cylinder seals.
4. Shock Plate Assembly - Yes, the disk is made from some highly compressed, super strong material but to merely call it "cardboard" implies something FAR less that it's true nature. In 38 years (Yes, I still use them) I've never seen (or heard) of these swelling or responding to moisture as you would expect cardboard to do. I have seen, though rarely, these plates get bowed from the impact of batteries when the light is dropped. The hammer effect of just 2 'D's dropped face first on even a carpeted floor will crush the end of a PR bulb. The Shock (Contact) Plate is well named.
1. One word of caution: on the front of this Contact Plate the positive (center) and negative (outer) contacts come VERY close together as they must to mate up with the bottom of the bulb. Several things can make them touch and short the battery -- NOT GOOD!
1. The plate getting bowed or domed (as above)
2. Using a bulb retainer on our (Qualtech) metal reflector mod. NOT from us. This is because the retainer pushes down on the negative plate as much or more than the base of the PR bulb and works against it making contact. It also deforms that whole U shaped negative contact and makes it short-out against the positive. That is WHY Qualtech turned down the shoulder of our bulb retainers to prevent that, but others supplied the mod. too, like Brinkman, without turning it down.
3. One of the little negative contacts (on the battery side) mentioned above (3.0) might snap off. Now you only need one of those contacts for electrical ground BUT they also mechanically hold the whole negative plate to the Shock Plate. With only one the plate could move and short against the positive.
1. Shock Plate contacts shorting:
1. On an old L.A. Screw made double-sided switch -- the internal contacts were so heavy all you might loose was one or both springs (tailcap & switch) as they heated up and collapsed. Both replaceable easily and cheap (then).
1. This actually caused Qualtech the most problem as our conversion to rechargeable endcap spring sets deep into a Lexan insulating sleeve. When the spring overheated the sleeve melted into it. The conversion endcap had to be rebuilt or replaced.
2. If contacts short on the newer one-sided button module the switch will 'pop' like a fuse. I think G.T. Price made the switch (pardon the pun) to a cheap, JUDCO brand switch and fit it into the 'original' switch module. JUDCO supplies millions of these little DC switches in the automotive and other industries. The most familiar ones might be the dome and map light switches in cars from the '90s onward. Initially, when G.T. were talking about this switch switch
we reminded them that cops want a blink option. They didn't even get the blink mode right with first ones blinking OFF from ON.
You asked about the time line and relationship between L.A. Screw & G.T. Price.
* All the before mentioned lights were manufactured by Police Equipment Div. of L.A. Screw Products Inc. since at least 1978 and probably earlier. They were at 8401 Loch Lomond Dr., Pico Rivera, CA
* Qualtech was founded in 1975 by its inventor Mr. Onno Prinsze in Scottsdale AZ. Sales began in 1976 converting 'C' & 'D' sized Kel-lites and Maglites. They also starting producing their own rechargeable named Pharo-tech.
* George Price and his 'point man' (national sales mgr.?) Ed Hecock of G.T. Price Products Inc. entered into the 'scene' in some capacity as early as 1985. They may not have owned it at this time. They were then at 2223 East 37th St. L.A. CA.
* By 1991 literature shows G.T. Price Products Inc. as the mfg. of Code Four and the others lights. They were then at 2320 Valencia Dr., Fullerton, CA