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40-473: Kamm , Kamp is a German or Jewish surname, from the German word for "comb", most likely a metonymic occupational surname for a comb maker, or a wool comber . Kamm is also an alternative form of the surname Kam , Kahm , Cam , Cahm (קם), from Middle High German kâm "mould". Notable people with the surname include: Fulling Waulking could be done with the hands and feet. In medieval Europe, it

80-400: A scroll chuck . Non-invertible functions, which require the groove to self-intersect, can be implemented using special follower designs. A variant of the face cam provides motion parallel to the axis of cam rotation. A common example is the traditional sash window lock, where the cam is mounted to the top of the lower sash, and the follower is the hook on the upper sash. In this application,

120-405: A cam for the lathe mechanism. A face cam produces motion by using a follower riding on the face of a disk. The most common type has the follower ride in a slot so that the captive follower produces radial motion with positive positioning without the need for a spring or other mechanism to keep the follower in contact with the control surface. A face cam of this type generally has only one slot for

160-497: A constant velocity rise followed by a similar return with a dwell in between as depicted in figure 2. The rise is the motion of the follower away from the cam center, dwell is the motion where the follower is at rest, and return is the motion of the follower toward the cam center. A common type is in the valve actuators in internal combustion engines. Here, the cam profile is commonly symmetric and at rotational speeds generally met with, very high acceleration forces develop. Ideally,

200-402: A convex curve between the onset and maximum position of lift reduces acceleration, but this requires impractically large shaft diameters relative to lift. Thus, in practice, the points at which lift begins and ends mean that a tangent to the base circle appears on the profile. This is continuous with a tangent to the tip circle. In designing the cam, the lift and the dwell angle θ are given. If

240-408: A device that converts rotational motion to reciprocating (or sometimes oscillating) motion. A common example is the camshaft of an automobile , which takes the rotary motion of the engine and converts it into the reciprocating motion necessary to operate the intake and exhaust valves of the cylinders . Cams can be characterized by their displacement diagrams, which reflect the changing position

280-614: A five-wheeled sand-driven clock, artificial paper figurines within a revolving lantern, all utilized cam mechanisms. The Chinese hodometer which utilized a bell and gong mechanism is also a cam, as described in the Song Shi. In the book Nongshu, the vertical wheel of a water-driven wind box is also a cam. Out of these examples, the water-driven pestle and the water driven wind box both have two cam mechanisms inside. Cams that rotated continuously and functioned as integral machine elements were built into Hellenistic water-driven automata from

320-422: A follower being raised over 24 hours by the cam in a spiral path which terminated at a sharp cut off at which the follower would drop down and activate the day advance. Where timing accuracy is required as in clocking-in clocks these were typically ingeniously arranged to have a roller cam follower to raise the drop weight for most of its journey to near its full height, and only for the last portion of its travel for

360-427: A follower on each face. In some applications, a single element, such as a gear, a barrel cam or other rotating element with a flat face, may do duty as a face cam in addition to other purposes. Face cams may provide repetitive motion with a groove that forms a closed curve or may provide function generation with a stopped groove. Cams used for function generation may have grooves that require several revolutions to cover

400-404: A follower would make as the surface of the cam moves in contact with the follower. In the example shown, the cam rotates about an axis. These diagrams relate angular position, usually in degrees, to the radial displacement experienced at that position. Displacement diagrams are traditionally presented as graphs with non-negative values. A simple displacement diagram illustrates the follower motion at

440-628: A key duplication machine, where the original key acts as a control cam for cutting the new key. Cam mechanisms appeared in China at around 600 BC in the form of a crossbow trigger-mechanism with a cam-shaped swing arm. However, the trigger mechanism did not rotate around its own axis and traditional Chinese technology generally made little use of continuously rotating cams. Nevertheless, later research showed that such cam mechanisms did in fact rotate around its own axis. Likewise, more recent research indicates that cams were used in water-driven trip hammers by

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480-399: A plate or block, may be one or more slots or grooves in the face of an element, or may even be a surface profile for a cam with more than one input. The development of a linear cam is similar to, but not identical to, that of a rotating cam. A common example of a linear cam is a key for a pin tumbler lock . The pins act as followers. This behavior is exemplified when the key is duplicated in

520-456: A shaft holding the cam to a set position by pressure from a roller. They were used on early models of Post Office Master clocks to synchronise the clock time with Greenwich Mean Time when the activating follower was pressed onto the cam automatically via a signal from an accurate time source. This type of cam was used for example in mechanical timekeeping clocking-in clocks to drive the day advance mechanism at precisely midnight and consisted of

560-409: A single rotation of the cylinder and generally provide positive positioning, removing the need for a spring or other provision to keep the follower in contact with the control surface. Applications include machine tool drives, such as reciprocating saws, and shift control barrels in sequential transmissions , such as on most modern motorcycles . A special case of this cam is a constant lead , where

600-432: A smooth reciprocating (back and forth) motion in the follower , which is a lever making contact with the cam. A cam timer is similar, and were widely used for electric machine control (an electromechanical timer in a washing machine being a common example) before the advent of inexpensive electronics, microcontrollers , integrated circuits , programmable logic controllers and digital control . The cam can be seen as

640-462: Is a rotating or sliding piece in a mechanical linkage used especially in transforming rotary motion into linear motion. It is often a part of a rotating wheel (e.g. an eccentric wheel) or shaft (e.g. a cylinder with an irregular shape) that strikes a lever at one or more points on its circular path. The cam can be a simple tooth, as is used to deliver pulses of power to a steam hammer , for example, or an eccentric disc or other shape that produces

680-432: Is mechanical analog computation and special functions in control systems. A face cam that implements three outputs for a single rotational input is the stereo phonograph , where a relatively constant lead groove guides the stylus and tonearm unit, acting as either a rocker-type (tonearm) or linear (linear tracking turntable) follower, and the stylus alone acting as the follower for two orthogonal outputs to representing

720-429: The nap raised by napping or gigging . The surface would then be sheared smooth. The process might be repeated for a smoother finish. The names for workers who performed these tasks ( fuller , tucker , and walker ) have become common surnames . The Welsh word for a fulling mill is pandy , which appears in many place-names, for example Tonypandy ("fulling mill lea"). Cam (mechanism) A cam

760-414: The audio signals. These motions are in a plane radial to the rotation of the record and at angles of 45 degrees to the plane of the disk (normal to the groove faces). The position of the tonearm was used by some turntables as a control input, such as to turn the unit off or to load the next disk in a stack, but was ignored in simple units. This type of cam, in the form of a symmetric heart, is used to return

800-417: The base (given) and r that of the tip circle (required): The most commonly used cam is the cam plate (also known as disc cam or radial cam ) which is cut out of a piece of flat metal or plate. Here, the follower moves in a plane perpendicular to the axis of rotation of the camshaft. Several key terms are relevant in such a construction of plate cams: base circle , prime circle (with radius equal to

840-409: The cam is used to provide a mechanical advantage in forcing the window shut, and also provides a self-locking action, like some worm gears , due to friction. Face cams may also be used to reference a single output to two inputs, typically where one input is the rotation of the cam and the other is the radial position of the follower. The output is parallel to the axis of the cam. These were once common

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880-465: The cam. The output is radial to the cylinder. These were once common for special functions in control systems, such as fire control mechanisms for guns on naval vessels and mechanical analog computers. An example of a cylindrical cam with two inputs is provided by a duplicating lathe , an example of which is the Klotz axe handle lathe, which cuts an axe handle to a form controlled by a pattern acting as

920-426: The cloth was taken out about every two hours to undo plaits and wrinkles. The 'foot' was approximately triangular in shape, with notches to assist the turning of the cloth. After fulling, cloth was stretched on great frames known as tenters, to which it is attached by tenterhooks (whence the phrase being on tenterhooks ). The area where the tenters were erected was known as a tenterground . Cloth would also have

960-503: The cloth while ankle deep in tubs of human urine . There are several Biblical references to fulling ( 2 Kings 18:17 ; Isaiah 7:3 and 36:2 ; Malachi 3:2 ; Mark 9:3 ). In addition to this, at least one reference appears in the speeches of Lysias , written in Athens during the 5th century BC. Scotland, then a rather remote and un-industrialized region, retained manual methods into the 1700s. In Scottish Gaelic tradition, this process

1000-404: The cloth, it absorbs oils and dirt. It was used in conjunction with wash. More recently, soap has been used. The second function of fulling was to thicken cloth by matting the fibres together to give it strength and increase waterproofing ( felting ). This was vital in the case of woollens , made from carded wool , but not for worsted materials made from combed wool. After this stage, water

1040-415: The complete function, and in this case, the function generally needs to be invertible so that the groove does not self intersect, and the function output value must differ enough at corresponding rotations that there is sufficient material separating the adjacent groove segments. A common form is the constant lead cam, where the displacement of the follower is linear with rotation, such as the scroll plate in

1080-563: The fibers to felt, so in practice the processes overlap. Urine was so important to the fulling business that it was taxed in Ancient Rome . Stale urine, known as wash or lant , was a source of ammonium salts and assisted in cleansing and whitening the cloth and having its fibers intertwined. By the medieval period, fuller's earth had been introduced for use in the process. This is a soft clay-like material occurring naturally as an impure hydrous aluminium silicate . Worked through

1120-430: The final portion of the run the profile of the non-roller cam rose more than the other causing the solid follower to take the weight. A linear cam is one in which the cam element moves in a straight line rather than rotates. The cam element is often a plate or block but may be any cross-section. The key feature is that the input is a linear motion rather than rotational. The cam profile may be cut into one or more edges of

1160-739: The latter half of the Western Han Dynasty (206 BC – 8 AD) as recorded in the Huan Zi Xin Lun. Complex pestles were also mentioned in later records such as the Jin Zhu Gong Zan and the Tian Gong Kai Wu, amongst many other records of water-driven pestles. During the Tang dynasty, the wooden clock within the water-driven astronoical device, the spurs inside a water-driven armillary sphere, the automated alarm within

1200-431: The machinery was operated by cams on the shaft of a waterwheel or on a tappet wheel, which lifted the hammer. Driving stocks were pivoted so that the foot (the head of the hammer) struck the cloth almost horizontally. The stock had a tub holding the liquor and cloth. This was somewhat rounded on the side away from the hammer, so that the cloth gradually turned, ensuring that all parts of it were milled evenly. However,

1240-412: The position of the follower is linear with rotation, as in a lead screw. The purpose and detail of implementation influence whether this application is called a cam or a screw thread, but in some cases, the nomenclature may be ambiguous. Cylindrical cams may also be used to reference an output to two inputs, where one input is the rotation of the cylinder and the other is the position of the follower along

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1280-399: The profile is treated as a large base circle and a small tip circle, joined by a common tangent, giving lift L , the relationship can be calculated, given the angle φ between one tangent and the axis of symmetry ( φ being ⁠ π / 2 ⁠ − ⁠ θ / 2 ⁠ ), while C is the distance between the centres of the circles (required), and R is the radius of

1320-438: The sum of the follower radius and the base circle radius), pitch curve which is the radial curve traced out by applying the radial displacements away from the prime circle across all angles, and the lobe separation angle ( LSA – the angle between two adjacent intake and exhaust cam lobes). The base circle is the smallest circle that can be drawn to the cam profile. A once common, but now outdated, application of this type of cam

1360-494: The various parts. A cylindrical cam or barrel cam is a cam in which the follower rides on the surface of a cylinder. In the most common type, the follower rides in a groove cut into the surface of a cylinder. These cams are principally used to convert rotational motion to linear motion perpendicular to the rotational axis of the cylinder. A cylinder may have several grooves cut into the surface and drive several followers. Cylindrical cams can provide motions that involve more than

1400-417: The weight to be taken over and supported by a solid follower with a sharp edge. This ensured that the weight dropped at a precise moment, enabling accurate timing. This was achieved by the use of two snail cams mounted coaxially with the roller initially resting on one cam and the final solid follower on the other but not in contact with its cam profile. Thus the roller cam initially carried the weight, until at

1440-677: Was a fulling mill established at Temple Guiting , Gloucestershire which was documented in the Domesday Book (also 1086). E. A. Lewis (possibly Welsh historian Edward Arthur Lewis ) observed: By the time of the Crusades in the late eleventh century, fulling mills were active throughout the medieval world. The mills beat the cloth with wooden hammers, known as fulling stocks or fulling hammers. Fulling stocks were of two kinds, falling stocks (operating vertically) that were used only for scouring, and driving or hanging stocks. In both cases

1480-637: Was accompanied by waulking songs , which women sang to set the pace. From the medieval period, the fulling of cloth was often done in a water mill , known as a fulling mill, a walk mill, or a tuck mill, and in Wales , a pandy. They appear to have originated in the 9th or 10th century in Europe. The earliest known reference to a fulling mill in France, which dates from about 1086, was discovered in Normandy . There

1520-480: Was automatic machine tool programming cams. Each tool movement or operation was controlled directly by one or more cams. Instructions for producing programming cams and cam generation data for the most common makes of machine, were included in engineering references well into the modern CNC era. This type of cam is used in many simple electromechanical appliances controllers , such as dishwashers and clothes washing machines, to actuate mechanical switches that control

1560-473: Was done in water-powered fulling mills. After the Industrial Revolution , coal and electric power were used. Felting refers more generally to the interlocking of loose wool fibers; they need not be spun and woven first. Fulling involves two processes: scouring (cleaning) and milling (thickening). Removing the oils encourages felting, and the cloth is pounded to clean it and to encourage

1600-427: Was used to rinse out the foul-smelling liquor used during cleansing. Felting of wool occurs upon hammering or other mechanical agitation because the microscopic scales on the surface of wool fibres hook together, somewhat like hook and loop fixings. Originally, fulling was carried out by the pounding of the woollen cloth with a club, or the fuller's feet or hands. In Roman times, fulling was conducted by slaves working

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