What is it? Set 296

[Rob H.]

This week's collection of photos has been posted:

[Polyp]

1688 Cable loom clip???? I'm sure I've seen it somewhere. 1690 Aluminium heatsink for some semiconductor. Thyristor ? Prolly 60's / 70's ??

1692 Switch sequencer, driven by "clock" motor seen on RHS. Programmed by pegs placed in the drum.

Thanks Rob, keep it up. :)

[Steve R.]

1690 heatsink for a power transistor

Steve R.

[Norman Billingham]

push work against a fence when routing or circular sawing

[Lee Michaels]

brass to be non sparking or non rusting. I have seen this type of rule from different materials and combinations thereof.

[Steve W.]

1687 - Folding rule, not sure what it was used for though with that strange scale. 1688 - Cable loom clip

1689 - Part of a feather board for a saw/router/shaper. Holds the board from kicking back.

1690 - Heat sink. From a very early semiconductor.

1691 -

1692 - Sequential switch. Not sure what it's from but it could be for lights or a display controller.

[Andrew Erickson]

Let's see...

1687 - Folding rule, obviously, but for some specialized purpose; possibly it has a draft scale for pattern making (for cast iron or other similar cast metals)

1688 - This looks somewhat familiar, but I'm not quite sure where. Possibly it's a holder for a (rather large) lavaliere microphone, to be clipped onto one's attire. The microphone capsule, of course, would be held in the circular portion. It could also be a clip for some other arbitrary use, like holding sunglasses on a car visor when they're not needed.

1689 - Probably a (part of) a featherboard, used with a table saw or related tool to prevent wood from kicking back. The pictures show it upside-down from its usual application.

1690 - Heat sink for a large (older) power transistor or other three-leaded semiconductor.

1691 - Possibly a tool to apply feet or ferrules to the ends of canes, chair or table legs, etc.?

1692 - Timer/controller from some piece of equipment; I'd guess it's for a "motion" sort of advertising light, and the big drum rotates at 1 rpm, making each numbered division one second. The sequence seems to be programmable by installing and removing the little black plastic bits on the drum. Contact 'S' looks like it was overloaded...

Now to read other guesses.

[Northe]

1687: I think it's a something like a gunner's level used for determining the correct angle of a cannon barrel to send the projectile a certain distance.

Northe

[Lloyd E. Sponenburgh]

1690 appears to be a heatsink for immersion in oil or water, though I don't recognize the device hole configuration.

[DoN. Nichols]

1687) At first glance, a folding carpenter's rule, but a closer look suggests that it is for navigation with maps. 1688) A clip-on paper guide -- perhaps for an inkjet printer or something similar. 1689) This looks like an anti-kickback guide for a wood saw, except that either the photo is reversed, or it was photographed from the bottom.

The fingers allow the workpiece to slide towards the blade, but if the blade jams in the work and tries to kick it back towards the operator, the fingers will bite in and hold it in position.

1690) A heatsink for a single transistor -- of the old doorknob style. I forget the TO-? number, but it was one of the early power transistor styles. The design suggests that it is cast, and then just machined flat where the transistor contacts it (through a possible insulating mica and some silicone based heatsink compound.

The shape suggests to me that it was probably from a car radio, and likely one from before stereo was common.

1691) Hmm ... an interesting thing -- and it looks as though there were multiple sources of illumination or multiple reflections from a display case, ad the shadows are showing up in multiples in some places.

I think that there should be a belt which goes from the tapered block down under the end, and back up to the lever operated winch on the other side to pull the workpiece (which looks somewhat like a spoke from a wagon wheel) to allow drilling or shaping the upper end.

1692) A drum encoder switch. 19 circuits individual switched by the black dots in the drum's slots. It is turned by an old electric clock style of synchronous gear motor, and I would guess that it provides one rotation of the drum every 24 hours, to switch on and off things like room lights, or to ring bells in up to 19 rooms at half-hour increments.

No -- perhaps not half hour increments, alternating (even) hours are not listed, and it looks as though it may either duplicate a second time around the drum, or go up to 48 or 50 positions.

The letters above the switch fingers are not to indicate letters being sent, but rather to identify the fingers, using a scheme similar to those on connector pins, where letters likely to be mistaken for others are dropped. Here, we are missing 'I', 'O', 'Q', and there is no need for 'X', 'Y', and 'Z', as all the pins are already accounted for.

Now to see what others have suggested.

Enjoy, DoN.

[Rob H.]

Yes, it's a wagon wheel spoke, the tool cuts a round tenon on it.

Rob

[Rich Grise]

Actually, it's for forced air. If it was liquid-cooled, it'd be a block with tubes bonded to or embedded in it.

That hole configuration was used many, many, many years ago for high- power germanium transistors. The hole in the middle accepts a stud that was integral with the package, and the other three are emitter, base, and collector, not necessarily in that order.

Hope This Helps! Rich

[Lloyd E. Sponenburgh]

Rich Grise fired this volley in news: [e-mail]:

Well, Rich, no... I have worked on similar-looking 'sinks that held stud SCRs with the whole affair immersed in a tank of silicone oil. (Old EMI CAT machines)

In fact, there's a PC on the market (for high-end gaming) that floods the entire chassis with oil, for a similar effect.

LLoyd

[J. Clarke]

And there are folks who dunk the whole machine into a liquid nitrogen bath.