Abstract: An angle adjustment and rotation system comprising a first element attachable to a luminaire stand, and a second element configured to be attachable to a luminaire head, the first element and second element comprising substantially complementary shapes, and an attaching element configured to have a first state in which it tightly attaches the first element to the second element and a second state in which it movably attaches the first element to the second element. In the second state, the attaching element enables a rotation over substantially 180 degrees of the second element with respect to the first element. A method of controlling the orientation of a luminaire head connected to a luminaire stand is also proposed, preferably using the proposed system.

Abstract: A lateral bracing system is disclosed for affixing a column to a beam in a construction. The lateral bracing system includes a pair of buckling restraint plates, one each affixed to a top and bottom flange of a beam. The lateral bracing system further includes at least one yield plate for each buckling restraint plate. Each yield plate includes a first end affixed to the column, and a second end affixed to the beam.

Abstract: A tool that is configured to align a polished rod within a carrier bar of a pumpjack is described. While this tool can include any suitable component, in some cases, it includes a cylindrical member having an internal conduit, such that the cylindrical member is configured to wrap around and receive the polished rod. In some cases, the cylindrical member has a top having a first outer diameter, and a bottom having a second, larger outer diameter. In some cases, a flange extends horizontally from the bottom of the cylindrical member, so as to be disposed at a bottom portion of the carrier bar when the cylindrical member is inserted into the carrier bar. In some cases, the cylindrical member comprises a slit that extends from the top to the bottom of the cylindrical member to allow the member to be opened and to receive the polished rod. Additional implementations are described.

Abstract: In an embodiment, a system includes a first structure comprising a first aperture and a second structure comprising a second aperture. The system also includes a first pin configured to be inserted into the first aperture of the first structure and a retaining device configured to be coupled to the first pin. The system further includes a second pin configured to be inserted into the second aperture of the second structure and coupled to the first pin. The first pin includes a first shoulder and a second shoulder, the first shoulder having a different diameter than the second shoulder.

Abstract: A surgical device for stabilizing or immobilizing moved tissue or for positioning organs, especially a part of a beating heart, includes a flexible arm, especially a link arm, fixed or fixable to a base member which arm can be brought into different positions and/or attitudes and at the free end of which at least one retaining element is arranged, and comprising a tightening mechanism by which the arm can be fixed at a desired position. The tightening mechanism is tightened and/or released by means of a manually controllable external power source.

Abstract: A rotation control device for a tool is disposed between a handle and a tool head and includes two ratchet wheels, a spring and two C-shaped snap rings. The two ratchet wheels are symmetrically arranged. When pressed, the respective ratchet wheels will be subjected to the same force and move the same distance, thus making the engagement between the ratchet wheels and the tool head more assured while avoiding the stuck fault and improving the convenience in use.

Abstract: A shift lever assembly for a manual transmission includes a hollow shift lever having a shift knob provided thereon. A noise and vibration damper includes a hollow housing that is connected to the hollow shift lever, and a damper assembly is provided within the hollow housing of the noise and vibration damper. The damper assembly is adapted to be connected to a control member of a manually operable transmission. A line extends from the shift knob provided on the hollow shift lever and through the interior of the hollow shift lever. The line is adapted to control the operation of the manually operable transmission.

Abstract: A clamping device is constructed and arranged to clamp two parts together. The clamping device includes an aligner constructed and arranged to bring the two parts in an aligned position with respect to each other, a clamp constructed and arranged to maintain the two parts in the aligned position, a disconnect constructed and arranged to guide the two parts away from the aligned position to a disconnected position, and an actuator constructed and arranged to convert an electrical current to kinetic energy. The aligner, the clamp, and the disconnect are constructed and arranged to be driven by the actuator.

Abstract: A break-away apparatus for a boom arm has a main boom portion and a boom tip. The apparatus is positioned at a joint between the main boom portion and the boom tip. The apparatus allows the boom tip to assume a neutral position and to pivot to a forward position and to a rearward position with respect to the main boom portion. The apparatus includes a first plate disposed at the joint, a second plate disposed at the joint, a hinge assembly positioned between the first plate and the second plate, a cam element attached to the first plate, the cam element having an arcuate surface, and a roller attached to the second plate and positioned to roll against the arcuate surface.

Abstract: A break-away apparatus for a boom arm is positioned at a joint between the main boom portion and the boom tip. The apparatus allows the boom tip to assume a neutral position and to pivot forward and rearward. The apparatus includes a first plate disposed at the joint, a second plate disposed at the joint, and a hinge assembly positioned between the first plate and the second plate. The hinge assembly includes a hinge pin having a longitudinal axis. The first and second plates are in a first position with respect to each other when the boom tip assumes the neutral position. The first and second plates are movable with respect to each other about the longitudinal axis. A torsion spring is configured to return the first and second plates to the first position after the first and second plates move from the first position.

Abstract: A break-away joint apparatus is disclosed for a boom arm having a front side and a back side, the boom arm having a main boom portion and a boom tip. The apparatus allows the boom tip to assume a neutral position and to pivot to a forward position and to a rearward position with respect to the main boom portion. The apparatus includes a first hinge connected to the main boom portion proximate one of the front or back side of the boom arm; a second hinge connected to the boom tip proximate an opposite side of the boom arm; and a pivot plate having first and second opposite sides, the first side connected to the first hinge and the second side connected to the second hinge.

Abstract: The invention relates to a connection for releasably connecting two parts of an electro-mechanical device, the connection including: a first connecting portion associated with a first part, and a second connecting portion associated with a second part, such that engagement of the first and second connecting portions imparts bias between the two parts, and a retention means suitable for maintaining the bias between the two parts.

Abstract: The invention relates to a coupling (10) which comprises a first component (12) and a second component (14) as well as a spring-loaded entrainer (16) which is spring-loaded and mounted on said first component (12), which second component (14) is furthermore rotatably mounted relative to said first component (12) and can be made to rotate in a first direction of rotation—the freewheeling direction (F)—and in a second direction of rotation—the blocking direction (S)—opposite to said first direction of rotation, which second component (12) furthermore comprises a guide means (18) which is designed so as to prevent a spring-loaded entrainer (16) from engaging said guide means (18) during rotation of said second component (14) in the freewheeling direction (F).

Abstract: An attachment assembly is configured to couple a panel assembly to a support member. The attachment assembly includes a first attachment member and a second attachment member movably coupled to the first attachment member. As such, the second attachment member is configured to move relative to the first attachment member. The second attachment member defines a cavity portion. The attachment assembly further includes a locking member movably coupled to the first attachment member between an unlocked position and a locked position. When the locking member is in the unlocked position, the second attachment member is movable with respect to the first attachment member. In the locked position, the locking member is at least partially disposed in the cavity portion, thereby fixing the position of the second attachment member with respect to the first attachment member.

Abstract: An adjustable holding device for sensors, including a main body, on and opposite which a bearing body supporting the at least one sensor is adjustably held by at least one spherical joint having a threaded stud fastened to the main body and protruding through a through-opening in the bearing body and to which an opening in a body having a spherical outer surface is screwed, said outer surface being held pivotably in complementarily spherical inner surfaces of two combined half-shells, and held co-rotatably together with the half-shells about an axis of rotation which is coaxial with the threaded stud and about which the half-shells are accommodated rotatably in the through-opening in the bearing body so that, by a rotation under external force of the at least rotationally coupled half-shells as to the through-opening, the body having the spherical outer surface can be screwed relative to the threaded stud by displacing the half-shells and the bearing body in the direction of the threaded stud.

Abstract: A locking apparatus for use with a head fixation device allows for a stabilizing fixture, such as a rocker arm having a pair of skull pins, to be selectively secured so that the stabilizing fixture can be adjustably rotated to a desired position. In some version the locking apparatus includes a connector that is retained within an opening in a portion of the head fixation device. The connector can translate within the opening and is restricted from rotation. The translating of the connector permits the connector to engage an arch member that retains the stabilizing fixture. The engagement of the connector and arch member is accomplished, in some versions, by way of matching axial oriented toothed portions or starburst features. In some versions the teeth on the starburst features include a chamfer surface.

Abstract: In accordance with an exemplary embodiment of the invention, a friction plate assembly is provided. The assembly includes a locking member having a toothed portion, a bolt extending through the locking member, and a friction plate configured for frictional engagement with the locking member. The friction plate receives the bolt therethrough and includes at least one biasing member configured to bias the bolt and the locking member in a first direction. When a predetermined force acts on the at least one biasing member, the friction plate is configured to force the locking member toothed portion into engagement with an object to facilitate preventing movement of the bolt in a second direction.

Abstract: A ride steer adjustment device for a vehicle includes an insert sleeve that has an opening configured so that the insert sleeve has an interference fit with a tie rod ball stud when the tie rod ball stud extends through the opening. The insert sleeve has external threads and is configured to be threaded to the knuckle steer arm at the external threads. A distance between the knuckle steer arm and the tie rod is adjustable by turning the insert sleeve relative to the knuckle steer arm at the external threads. Adjusting the distance between the knuckle steer arm and the tie rod changes the angle of the tie rod and thereby the ride steer.

Abstract: A sliding lock mechanism that utilizes a binding bar to prevent movement of a sliding member on a slide rail in at least one direction. A spring mechanism exerts a biasing force on the binding bar to maintain the locked position. The binding bar can be moved to an unlocking position by overcoming the bias of the spring. This then allows movement of the sliding member in two directions on the slide rail. An actuating rod moves the binding bar between the first and second positions. The mechanism can be added to a stowing mechanism for a laptop or other device that can secure different devices with varying widths within a compartment due to a drive spring mechanism. The addition of the locking mechanism allows for greater security of the laptop during periods of vibration and prevents backdriving of the spring mechanism.

Abstract: A swiftly-assembling collapsible goal and a portable frame are provided. The goal includes a plurality of poles engaged together to form a frame of the goal. Engaged poles are associated with each other with a hinge disposed at a corner region therebetween. One of two engaged poles is provided with a tenon protruding from a first end thereof and the other pole of the two engaged poles is provided with a mortise slot at a second end of the other pole facing toward the first end. The tenon defines a wedge-shaped slot along an axis of the pole. An insert pin is engaged to the tenon with a wedge-shaped rib engaged in the wedge-shaped slot. The insert pin has two tabs laterally extending from two side surfaces thereof. The pole with mortise slot defines two slits in two sidewalls which define the mortise slot, for respectively receiving the two ribs therein. The tenon and the insert pin are received in the mortise slot.

Abstract: A universal tiltable joint (10) for a lighting fixture (11) includes a first joint portion (12) having an axial joint axis (A), a second joint portion (14) having the axial joint axis, one of the first joint portion and the second joint portion housed co-axially within the other of the first joint portion and the second joint portion, a co-axial gap (60) between the first joint portion and the second joint portion allowing movement at an angle to the axial joint axis, the movement causing at least one of engagement or disengagement of a safety feature (27) on the first joint portion and the second joint portion.

Abstract: A safety lockout system for releasably locking a mast guided working surface to a mast is provided. The safety lockout system may include an outer rollcase, an inner rollcase, and a lockout assembly. The lockout assembly includes a retractable dog that is movable between an engaged position and a disengaged position. The lockout assembly may include a dog release device that operates both manually and automatically to move the retractable dog from the disengaged position to the engaged position. Automatic operation of the dog release device is triggered when the working surface experiences a tilted condition. A dog emergency release device may be provided to manually move the retractable dog to the disengaged position in the event of a malfunction. The lockout assembly may include a lockout assembly locking device that allows a portion of the lockout assembly to fold up and move the retractable dog to the disengaged position.

Abstract: A connection unit cooperates with a rod when in use. The connection unit includes a fixing member, a pin rod, an oblique detent and a knob. The fixing member has an axial slide hole for insertion of the rod and a transverse hole. The pin rod has a slope at a middle section thereof corresponding to the oblique detent. The pin rod is driven by the knob. The oblique detent is fixed on the fixing member. The connection unit can be applied for connection of two rods or for positioning of a fixing member of a rod. The operation is simply and labor-saving. The connection unit can be widely used.

Abstract: A cap assembly for a vehicle includes a base and a cap pivotally mounted to the base. The base can define a recess for receiving a component therein to be captured by the cap. The cap is moveable between a locked position and an unlocked position. The cap includes a locking feature that maintains the cap in the locked position and urges the cap to the locked position when nearly in the locked position. When the cap is in the locked position, the component is locked within the recess. When the cap is in the unlocked position, the component is removable from the recess.

Abstract: A rotation joint and methods for rotationally coupling a swing tip assembly to a fluid-dynamic body are presented. A rotation plate configured to couple to the swing tip assembly comprises a slide ring comprising an open center, an upper slide surface, an inner slide surface, and a lower slide surface. An upper joint plate is slidably coupled to the upper slide surface and the inner slide surface is configured to couple the fluid-dynamic body. A lower joint plate is slidably coupled to the lower slide surface and the inner slide surface, and is coupled to the upper joint plate through the open center. The lower joint plate is configured to couple to the fluid-dynamic body.

Abstract: A rotary joint for a vehicle seat is movable between at least two positions. The rotary joint includes an outer bearing comprising two shell halves, which, when forced together by a mechanical fastener, compress a rounded space between the two shell halves. The rotary joint further includes an inner bearing held between the two shell halves and rotatable relative to the outer bearing via rotation within the shell halves. The inner bearing includes a sleeve forming the outer surface and having an elastic property to reduce non-rotational movement outer bearing and the inner bearing.

Abstract: A connector and method of connecting two surfaces in an irregular, interrupted, or non-uniform space is provided. The connector is composed of at least one link, wherein each link has an adjustable spatial feature such as the length, thickness, or angle of the link. The spatial features of the links are adjusted to custom fit the connector to the two surfaces and the available space therebetween. Once the links have been adjusted to provide a satisfactory custom fit, the adjustable spatial features of the links may be fixed to form a substantially permanent solid structure or may be recorded to allow production of a custom shaped connector with substantially the same spatial features as the custom fit connector.

Abstract: An expandable device including: a first member; a second member; at least one tension member attached to the first and second members and extending between the first and second members, the first and second members movable between an open position, in which at least a part of the first member is spaced from the second member, and a closed position, in which said at least a part of the first member is adjacent the second member; and at least one spacer sized to be located between the first and second members when in the open position, and to maintain the first and second members in the open position, wherein, in the open position, the at least one tension member is held taut between the first and second members.

Abstract: A force compensating device includes a force generating unit configured for generating a compensating force that at least partially counteracts a tractive force acting on the force compensating device. The device includes at least one safety unit that is rotatable about a first axis of rotation and which, in the event of a malfunction of the force generating unit, can be moved by the force generating unit from an operating position to a locked position. The safety unit includes a first element and a second element that are rotatably connected to each other at a second axis of rotation, and at least one locking unit that blocks rotational movement of the safety unit from the locked position back to the operating position when the safety unit has been triggered due to a malfunction. A two-part safety unit in combination with the locking unit allows the safety unit to trigger and remain triggered in all fault situations. The force compensating device may be used in a medical system.

Abstract: Disclosed is a hinge with securing features, the hinge including a first hinge body portion including a first frame association end and a nesting cavity, the first frame association end and the nesting cavity being disposed at opposite ends of the first hinge body portion, a second hinge body portion defining a second frame association end and a nesting body configured for nesting in the nesting cavity of the first hinge body portion, the second frame association end and the nesting body being disposed at opposite ends of the second hinge body portion, wherein the first hinge body portion and the second hinge body portion are rotatably associated via a pivot point, and at least one securing feature configured for securing the nesting body within the nesting cavity in a manner that prevents rotation of the first body portion relative to the second body portion about the pivot point.

Abstract: The present invention relates to outdoor grill accessories, and more particularly, a foldable worktable attachment for an outdoor grill that includes a large table area that is interconnected to a lower shelf by two sets of foldable legs. When in an erect position, the table provides ample space for preparing foods and the like, but when in a collapsed position, the table lies flush against one of the sides of the grill housing, thus, enclosing the lower shelf and supporting legs that are folded and stored between the table and a recessed area included in the grill housing.

Abstract: The present invention relates to an adjustable fixation or locking means for two parts or portions by use of sliding hinge. The parts or portions are to be used or utilized in furniture and/or human necessity products, such as e.g. different types of chairs, sofas, wheelchairs, etc.

Abstract: A fluid turbine comprises a rotor rotatable in use about an axis transverse to the direction of fluid flow, the rotor having a first part carrying a plurality of arcuate blades that may be arranged selectably in compact straight shapes or in arcuate shapes and a second part journalled in a base structure by two or more bearings. Another aspect of the invention discloses an installation frame, devised to support the turbine or other elongated structures in a folded arrangement for transportation on a trailer, and to support assembly and erection thereof.

Abstract: A rotation control device for a tool is disposed between a handle and a tool head and includes two ratchet wheels, a spring and two C-shaped snap rings. The two ratchet wheels are symmetrically arranged. When pressed, the respective ratchet wheels will be subjected to the same force and move the same distance, thus making the engagement between the ratchet wheels and the tool head more assured, while avoiding the stuck fault and improving the convenience in use.

Abstract: A fail-safe attachment is provided for coupling an exoskeletal prosthesis to a patient limb having a bone anchored mounting post with an external fixation structure. The fail-safe attachment comprises a first component adapted for connection to the fixation structure, and a second component adapted for connection to the prosthesis. A safety release mechanism is provided normally retaining the prosthesis in a rigid substantially motion-free interconnected relation to the fixation structure, said safety release mechanism responding to a force overload condition to permit relative movement between the prosthesis and the fixation structure. The safety release mechanism comprises a bending force release mechanism responsive to a bending force overload condition to permit the separation of the second component relative to said first component.

Abstract: A swivel mechanism for a rotating cantilever post including a cantilever boom and a post, the swivel mechanism comprising at least one first gear associated with the cantilever boom and at least one second gear rotatably mounted to the post, wherein the at least one second gear is operatively associated with the at least one first gear such that rotation of the at least one second gear causes rotation of the at least one first gear, rotating the cantilever boom relative to the post.

Abstract: A saw attachment mechanism includes at least one guide roller configured for releasable engagement with a track, a guide roller shaft and a guide roller pivot, each coupled to the guide roller, at least one pushrod configured for engagement with the guide roller shaft, and a cam shaft coupled to a handle. The guide roller can rotate around a guide roller axle. The guide roller pivot is coupled to the one guide roller to allow rotation of the guide roller and guide roller shaft toward and away from an engaged configuration. The pushrod can engage the guide roller shaft at a first end and the cam shaft at a second end. As the cam shaft is rotated, the pushrod slides to engage the guide roller shaft, to swing the guide roller shaft into an engaged position.

Abstract: A tool accessory (10) for clamping a pair of multimeter probes allowing the probes to pivot relative to each other or separate from each other to be used separately for testing electrical components. The tool accessory (10) behaves as a pair tweezers. The tool accessory (10) utilizes a lock (16) that adjusts the angle of the probes. The lock (16) also biases the probes via pushing a pair of legs (12, 14) of the tool accessory (10).

Abstract: In an anchoring device, a drill head and expansion element(s) are configured to cooperatively interlock with each other to provide for directed movements of the drill head relative to a longitudinal axis of the shaft. Co-operating contact surfaces between the drill head and the expansion element(s) are configured such that relative longitudinal movement of the drill head with respect to the expansion element(s) displace(s) the expansion element(s) outwardly so the expansion element(s) can provide frictional contact with a borehole once inserted therein.

Abstract: A pivoting ball mount provides four essentially equal and (generally) evenly spaced constraints on the ball, creating a ball and socket joint in which the “socket” is composed of four small constraining pads of equal size and equally spaced around the surface of the ball or sphere. If a sphere is constrained by four equidistant points, each point will exert the same amount of force on the sphere. If additional pressure is applied to one point, the pressure exerted by the other points will rise to match this increased pressure. The effect of constraining a smooth ball by four equidistant points is to create the equivalent of a ball and socket joint in which the force required to rotate the ball at a particular rate is about the same in any direction. The ball is constrained by four equidistant points such that the relative movement between the ball and housing is smooth and predictable in any direction.

Abstract: A safety lockout system for releasably locking a mast guided working surface to a mast is provided. The safety lockout system may include an outer rollcase, an inner rollcase, and a lockout assembly. The lockout assembly includes a retractable dog that is movable between an engaged position and a disengaged position. The lockout assembly may include a dog release device that operates both manually and automatically to move the retractable dog from the disengaged position to the engaged position. Automatic operation of the dog release device is triggered when the working surface experiences a tilted condition. A dog emergency release device may be provided to manually move the retractable dog to the disengaged position in the event of a malfunction. The lockout assembly may include a lockout assembly locking device that allows a portion of the lockout assembly to fold up and move the retractable dog to the disengaged position.

Abstract: A reinforcing arrangement for reinforcing a joint portion between two support units of a foldable furniture object, comprising a first mounting unit which comprises a first mounting body and a first guiding member outwardly protruded from the first mounting body mounting on the first support unit; a second mounting unit which comprises a second mounting body and a second guiding member or a second guiding groove complimentary to and moveably engaging with the first mounting unit to define a maximum extending angle of movement, thereby the first and second support unit are guided to lock into position at an unfolded position at the maximum extending angle and to unlock at a folded position; and a connecting unit pivotally connecting the first support unit and the second support unit between which the two mounting units are positioned, thereby the joint portion is reinforced.

Abstract: An apparatus applies product and includes a pivotal platform solely supported through bushings formed of compressible material. The ground speed can be locked by stepping on a step pivoting a composite block to engage with an engagement of the transmission proportioner arm. A gate is opened utilizing a control lever pivotally mounted to a pivotably mounted control block to either engage or avoid a tang of an adjustment guide. A drive belt system includes a variator having first and second sheaves having variable effective diameters when their pivot pin is moved by pivoting a lever. A spray tip sprays a fan style spray at a small acute angle to the application area. A flip shield is pivoted about an axis parallel to the movement direction and includes a linear straight portion parallel to the axis in a redirection position.

Abstract: A connection mechanism is used for rotatably connecting a first object and a second object. The connection mechanism includes a positioning member capable of being inserted in a first fixing hole defined in the first object and the engaging hole defined in the second object for connecting the first object and the second object. The positioning member is slidable in the first fixing hole and in the engaging hole to interchange between a first position and a second position, the positioning member is received in the first fixing hole and the engaging hole to restrict the first object from rotating relative to the second object in the first position, and at least move out of the first fixing hole or the engaging hole to allow the first object to rotate relative to the second object in the second position.

Abstract: A locking and unlocking device (10) for forming an interface between the shell (1) and the collar (2) of a sports boot, which comprises a rocker (11) that is movable in rotation about a pin (13), a lever (15) that is movable in rotation and an elastic element connected to the lever (15), such that the lever (15) is able to occupy a first stable position, in which it holds the rocker (11) in a locking position, and a second stable position, in which it holds the rocker (11) in an unlocking position.

Abstract: A tool accessory (10) for clamping a pair of multimeter probes allowing the probes to pivot relative to each other or separate from each other to be used separately for testing electrical components. The tool accessory (10) behaves as a pair tweezers. The tool accessory (10) utilizes a lock (16) that adjusts the angle of the probes. The lock (16) also biases the probes via pushing a pair of legs (12, 14) of the tool accessory (10).

Abstract: A locking system for a multitool where multiple discrete lock members are attached to a handle and the lock members can be individually engaged to lock and unlock tool members from a retained to an extended position and vice versa within the handle of a multitool.

Abstract: A latch assembly is suitable for a ramp assembly, the ramp assembly having a ramp portion coupled to a fixed portion so that the ramp portion reciprocates between a stowed position and a deployed position. The latch assembly includes a latch pin attached to the ramp portion. The latch assembly further includes a latch fitting coupled to the fixed portion of the ramp assembly. The latch fitting has a hook portion and a tang. The latch fitting selectively reciprocates between a first position, a second position, and a third position. In the first position, the hook engages the latch pin to retain the ramp portion in the stowed position. In the second position, the hook portion is disengaged from the latch pin. In the third position, the tang applies a lifting force to the ramp portion.

Abstract: The present invention relates to a device for connecting at least one external functional device to an arrangement, wherein the device includes at least one first contact portion and at least one second contact portion for receiving the external functional device between the first contact portion and the second contact portion, and at least the first contact portion or the second contact portion is movable. It further relates to a method for connecting at least one external functional device to an arrangement by using the device of the present invention, as well as an arrangement which includes at least one device of the present invention.

Abstract: A two-section tool joint comprises a support member including a polygonal ball knob disposed on one end thereof; an acting head including a receiving chamber fixed on end thereof, and on a side wall of the receiving chamber being arranged a plurality of raised rims in response to the ball knob; a limiting structure defined between the support member and the acting head so that the ball knob of the support member is limited in the receiving chamber and moves between a first and a second positions; wherein the raised rims are longitudinally defined on a side wall of the receiving chamber and spaced apart equally from each other, the number of the raised rims is in response to that of the angles of the ball knob, and each raised rim is provided with a convex arc contacting surface so that the support member rotates with the acting head.