A pantograph is a mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen. If a line drawing is traced by the first point, an identical, enlarged, or miniaturized copy will be drawn by a pen fixed to the other. Using the same principle, different kinds of pantographs are used for other forms of duplication in areas such as sculpting, minting, engraving, and milling.
A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the flow of current more precisely. Galvanometers work by deflecting a pointer in response to an electric current flowing through a coil in a constant magnetic field. The mechanism is also used as an actuator in applications such as hard disks.
Benjamin Banneker was an African-American naturalist, mathematician, astronomer and almanac author. A landowner, he also worked as a surveyor and farmer.
A graphics tablet is a computer input device that enables a user to hand draw or paint images, animations and graphics, with a special pen-like stylus, similar to the way a person draws pictures with a pencil and paper by hand.
Duplicating machines were the predecessors of modern document-reproduction technology. They have now been replaced by digital duplicators, scanners, laser printers and photocopiers, but for many years they were the primary means of reproducing documents for limited-run distribution. The duplicator was pioneered by Thomas Edison and David Gestetner, with Gestetner dominating the market up until the late 1990s.
A windscreen wiper or windshield wiper is a device used to remove rain, snow, ice, washer fluid, water, or other debris from a vehicle's front window. Almost all motor vehicles, including cars, trucks, buses, train locomotives, and watercraft with a cabin—and some aircraft—are equipped with one or more such wipers, which are usually a legal requirement.
In kinematics, the parallel motion linkage is a six-bar mechanical linkage invented by the Scottish engineer James Watt in 1784 for the double-acting Watt steam engine. It allows a rod moving practically straight up and down to transmit motion to a beam moving in an arc, without putting significant sideways strain on the rod.
A swingarm, or "swinging arm" (UK), originally known as a swing fork or pivoted fork, is a single or double sided mechanical device which attaches the rear wheel of a motorcycle to its body, allowing it to pivot vertically. The main component of the rear suspension of most modern motorbikes and ATVs, it holds the rear axle firmly, while pivoting to absorb bumps and suspension loads induced by the rider, acceleration, and braking.
A bipod is a V-shaped portable attachment that helps support and steady a device, usually a weapon such as a long gun or a mortar. The term comes from the Latin prefix bi- and Greek root pod, meaning "two" and "foot" respectively.
A Watt's linkage is a type of mechanical linkage invented by James Watt in which the central moving point of the linkage is constrained to travel a nearly straight path. Watt's described the linkage in his patent specification of 1784 for the Watt steam engine.
In the study of mechanisms, a four-bar linkage, also called a four-bar, is the simplest closed-chain movable linkage. It consists of four bodies, called bars or links, connected in a loop by four joints. Generally, the joints are configured so the links move in parallel planes, and the assembly is called a planar four-bar linkage. Spherical and spatial four-bar linkages also exist and are used in practice.
A chart recorder is an electromechanical device that records an electrical or mechanical input trend onto a piece of paper. Chart recorders may record several inputs using different color pens and may record onto strip charts or circular charts. Chart recorders may be entirely mechanical with clockwork mechanisms, electro-mechanical with an electrical clockwork mechanism for driving the chart, or entirely electronic with no mechanical components at all.
A jack is a mechanical lifting device used to apply great forces or lift heavy loads. A mechanical jack employs a screw thread for lifting heavy equipment. A hydraulic jack uses hydraulic power. The most common form is a car jack, floor jack or garage jack, which lifts vehicles so that maintenance can be performed. Jacks are usually rated for a maximum lifting capacity. Industrial jacks can be rated for many tons of load.
A balanced-arm lamp, sometimes called a floating arm lamp, is a lamp with an adjustable folding arm which is constructed such that the force due to gravity is always counteracted by springs, regardless of the position of the arms of the lamp. Many lamp brands, as well as other devices, use this principle.
A straight-line mechanism is a mechanism that converts any type of rotary or angular motion to perfect or near-perfect straight-line motion, or vice versa. Straight-line motion is linear motion of definite length or "stroke", every forward stroke being followed by a return stroke, giving reciprocating motion. The first such mechanism, patented in 1784 by James Watt, produced approximate straight-line motion, referred to by Watt as parallel motion.
Technical lettering is the process of forming letters, numerals, and other characters in technical drawing. It is used to describe, or provide detailed specifications for, an object. With the goals of legibility and uniformity, styles are standardized and lettering ability has little relationship to normal writing ability. Engineering drawings use a Gothic sans-serif script, formed by a series of short strokes. Lower case letters are rare in most drawings of machines.
Astronomical rings, also known as Gemma's rings, are an early astronomical instrument. The instrument consists of three rings, representing the celestial equator, declination, and the meridian.
A physiognotrace is an instrument, designed to trace a person's physiognomy to make semi-automated portrait aquatints. Invented in France in 1783–1784, it was popular for some decades. The sitter climbed into a wooden frame, sat and turned to the side to pose. A pantograph connected to a pencil produced within a few minutes a "grand trait", a contour line on a piece of paper. With the help of a second scaling-down pantograph, the basic features of the portrait were transferred from the sheet in the form of dotted lines to a copper plate, which had previously been prepared with a ground for etching. One week later, the sitter received an etched plate and twelve little prints. The device but also the aquatint prints are called physionotraces.
A leg mechanism is a mechanical system designed to provide a propulsive force by intermittent frictional contact with the ground. This is in contrast with wheels or continuous tracks which are intended to maintain continuous frictional contact with the ground. Mechanical legs are linkages that can have one or more actuators, and can perform simple planar or complex motion. Compared to a wheel, a leg mechanism is potentially better fitted to uneven terrain, as it can step over obstacles.
In kinematics, a five-bar linkage is a mechanism with two degrees of freedom that is constructed from five links that are connected together in a closed chain. All links are connected to each other by five joints in series forming a loop. One of the links is the ground or base. This configuration is also called a pantograph, however, it is not to be confused with the parallelogram-copying linkage pantograph.
