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Inside a ratchet: How they work
bonneyman:
It seems that many of you are interested in the inner workings of ratchets, and how they differ.
I will post pics of the insides of various brands of ratchets that have come across my desk, along with the names that I give the different designs. This should help to "standardize" the different gear mechanisms, so we are all on the same page as far as terminology is concerned. This should help individuals troubleshoot problems, facilitate repairs, and/or obtain the correct repair kit for our problem ratchets.
Here's a list of the most common category's compiled thus far. Grouped together at the beginning so it's easier to add to later, and the pictures follow.
Pear head rats
- "Batman" pawl (1,2, or 3 tooth on each "wing")
- "D" pawl
- "Nighthawk" pawl
- "Tic-Toc" pawls (almost always in pairs) https://patents.google.com/patent/US2803980
- Rectangular pawls
- "Two step" pawls
- Free floating pawl (single or double)
- "Canoe" pawl - totally free "floating" pawl sitting on spring
Round head rats
- "See-Saw" pawl (single or double pawls that rock back and forth)
- "Sliding" pawl (pawl "slides" on a shelf forged into the gear assembly)
- Semi-Free floating pawl (pawl sits on spring tip and is pivoted with two pegs by a plate)
- Stair stepper pawls (i.e. Crescent roundhead) https://patents.google.com/patent/US2715955
Frankenstein rats
- Sliding rod selector/pawl (1,2, or 3 tooth)
Open head rats
- "Waterwheel" gears
- Single tic-toc type of pawl. (Used alot on refrigeration wrenches)
- Single Nighthawk pawl
Universal head rats
- Floating ball head (New Britain)
https://patents.google.com/patent/US2709386
https://patents.google.com/patent/US2800821
Ratcheting wrenches (one direction ratcheting, non-reversible)
- Box end
- Winch style pawl (old Dunlap)
- Rocker type pawl
- Open end
- Cam-Loc (floating pins) https://patents.google.com/patent/US2550010A/en?oq=Cam+Loc+2550010
- Moveable lower jaw (common of newer ratcheting open end wrenches) - Chicago and Alden brand (China)
Mini-ratchets
- Reversible - Flip toggle (Yankee, General tools, others)
- Non-reversible - Single tic-toc pawl (Chapman)
Pear head rats:
An Indestro 6272 used what I call a "batman" pawl. The 3/8"er had 24 teeth gear
The pawl reminds me of the trademark "Batman" symbol from the old 60's TV show.
The corresponding 1/4" version (6072) has 24 teeth also
The old Plomb WF-series rats used a pair of "tic-toc" pawls - so named because the action of the pawls is like an old grandfather clock. The 1/4" version ahd 24 teeth, and the corresponding 3/8" version (WF-21) has 24 teeth as well.
Round head rats:
The very popular S-K 45170 in 3/8" uses an integrated floating pawl.
https://patents.google.com/patent/US2232477
But it's much easier to remember it as a "see-saw" pawl.
This is one of the most commonly copied actions. You find it on many ratchets, including Craftsman Tri-Wings, Stanley, old Thorsens, and others.
The Bonney -702 round head rats used a pair of floating "see-saw" pawls integrated into the gear head. This design is no stronger than a single see-saw pawl (as only one pawl engages head teeth at a time), but it is longer lasting (as there are two pawls to divide the work) and it effectively "doubles" the amount of teeth, as the gear only has to rotate half as much to get a click. So, although both rats have only 36 teeth, the action is one of a 72 tooth. Nice!
Another brand that uses the design is the ever popular Craftsman RHFT.
The S-K TUFF 1 rats used the FACOM design which I call a "sliding" pawl. Other brands that use this design are the FACOM round heads and the Stanley-made Master-Pro rats, as well as the Craftsman Quik Clean and Tri-Prop rats.
There's much more to come, so, stay tuned. Better yet, if you have any ratchet that is not shown, post up some pics. Tell us what you call them, so we can all learn something. Let's make this a great thread!
bonneyman:
Here's some more rats!
An Indestro Super 2775 in 3/8". It used a variation of the single see-saw pawl which I call the "pilot wings" pawl, with two bearing balls to reduce friction. https://patents.google.com/patent/US2686582
An easy-to-spot "Frankenstein" ratchet, so named because the switching rod sticks out of the neck of the head. S-K and Wright also made "Steiny" rats. https://patents.google.com/patent/US2701977
Here is a Bonney refrigeration wrench, RF-22. It uses what I call a "water wheel" gear, because it reminds me of those old riverside mills with the big wooden waterwheels.
Many other older ratchets (Thorsen, Action, Wright, etc) used a similar design, known as the "open" style of gear head.
Duro 672 rats used a variation of the batman pawl. Since the triangular pawl looks like a F-117 stealth fighter, I call it a "nighthawk" pawl.
bonneyman:
Craftsman teardrop-shaped ratchets:
All of the C-man teardrop (i.e pearhead) ratchets use a variation of the batman pawl. The only differences are how they are assembled. It appears that, as time went on, the amount of machining was reduced, and the manufacturers found simpler (i.e. cheaper) ways of assembly. I've listed them with the newest style first, and getting older as you go down the post.
Here's the standard teardrop ratchet available in Sears stores now (since 1993), with what I call the figure-8 plate. So named because the front cover plate looks like an "8".
It is a variation of the batman pawl, with 3 teeth on "wing".
The design it replaced is commonly known as the LLTD (long lever tear drop) ratchet, made from 1957 thru 1992.
I call this a "baby rattle" selector lever, whereas the figure-8 plate selector is a "manta ray". Notice that the pawl on this rat is the older style, with a "D" post. The newest examples have a hyphen-shaped "tang" on them. And this pawl has 2 teeth per wing.
When you place the two side-by-side, it's easy to tell them apart.
The LLTD is on the left, the figure-8 is on the right.
bonneyman:
Some sliding pawl rats.
The first two pics feature a FACOM J.161 in 3/8", with the sliding pawl plainly visible:
The second pic is a Master Pro made by Stanley in 3/8"
The last pic is a Craftsman Tri-Prop (so-called because the selector disc looks like a plane propeller)
It utilizes a fish-hook style of spring with a bend for the pawl, rather than a heart-shaped spring.
benjy:
i have a facom 3/8 flexihead where the wire thingy is completly destroyed.. have you ever made new ones or must it be a service kit?
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