Adjustable wrench
An adjustable wrench is an adjustment key for loosening and tightening screw connections.
The distance between the clamping jaws can be continuously adjusted by turning a knurled screw. Thus it can be used for different sized squares or even multiple edges (6, 8, 10 ...), e.g. Eg for square nuts or - screw or for different unit systems ( metric , imperial ) and special works standards are used.
It was invented and patented (on May 11, 1892 under the patent number SE4066) by the Swede Johan Petter Johansson in his workshop Enköpings Mekaniska in Enköping , which he founded after inventing the water pump pliers in 1886 . BA Hjört & Co. ( Bahco ) then produced and marketed the tool all over the world from 1892 until today.
designation
Colloquial language
English is the colloquial term for all types of adjustable wrenches , especially those with a jaw only on one side. In the narrower sense, the Englishman is an adjustable wrench in which the adjustment of the width across flats is carried out via a threaded spindle in the tool shank. Most of the adjustable wrenches in use today, on the other hand, are adjusted via a worm gear in the wrench head (see picture). The correct term for such tools is adjustable wrench , also known as adjusting wrench .
Finally, there are the so-called French who, when closed, look like a hammer with a symmetrical head and a cylindrical, somewhat knurled handle. With these, the wrench size is changed via the interaction of a right-hand and a left-hand threaded spindle by turning the tool shank. Due to the different pitch of the thread, small travel ranges per revolution of the tool shank are possible. In contrast to the English and adjustable wrench, the French have a double jaw, which is used to insert a second nut of the same size into the second jaw opening, so that even high pressure from the differential screw does not tilt and rub the guide of the upper jaw.
Other tool designs
Since the jaws of the English and the adjustable wrench are only available on one side, they offer advantages over the French in confined spaces. In terms of durability and quality over the years, an open-end wrench or ring spanner is superior to the English because there are no moving parts. Adjustable wrenches can also be used for (hexagon) screws for which no suitable wrench is available.
Thus, the Englishman is not a competition to open-end or ring spanners, but a completion of the workshop equipment or the tool box.
The origin of the term English is presumed to be that in workshops this tool was used for cost reasons for the imperial (i.e. English - see also Joseph Whitworth ) screws and nuts, which are less common in continental Europe , if only metric open-end or ring spanners were available.
In the English-speaking world, the adjustable wrench is also known as an adjustable wrench or adjustable spanner. This was already invented in 1842 by Richard Clyburn; it had a slightly curved S-shape. Since 1990 the retired teacher Ian Harrison from England has been working on the further development of the adjustable wrench. In 2006 he invented Milli-grip. These pliers were awarded the gold medal at the British inventors fair. In contrast to the typical adjustable wrench, Milli-grip is simply compressed to the required size. The locking mechanism allows the jaws to engage in any millimeter increments. The pliers are unlocked by pressing a button. This allows you to switch between 8 mm and 32 mm width within seconds. Inadvertent adjustment of the key size is no longer possible.
handling
Improper handling can deform the tool: If an adjustable wrench of the shape shown in the picture is used to loosen or tighten screws or nuts, make sure that the movable part of the jaw or fork with its free end points in the direction of the rotary movement to be performed. If this is not observed, the movable side of the fork or the adjustment mechanism can be bent and, as a result, have increased play, making the tool unusable.
Furthermore, it is important to ensure that the width of the adjustable fork is as narrow as possible for the screw or nut to be turned. If the fork width is not chosen narrow enough, this can lead to sliding off the polygon. On the one hand, the screw or nut can be turned round . The corners are worn away by plastic deformation, and loosening or tightening eventually becomes impossible. There is a high risk of injury from slipping when using high physical strength.
With particularly careful handling, namely by firmly positioning the wrench jaws against the side surfaces of the nut to be turned, with no play, an adjustable wrench also transmits high torque more gently than an open-ended wrench, which, according to the standard, has a certain amount of play between the jaw and nut so that it can be pushed open easily guarantee if the nut shows a certain excess due to production, scratches or painting. Each time the key is repositioned, preferably even if the force is simply interrupted, the jaws should be adjusted again, as they tend to loosen by shaking much more than with the French.
