Abstract: A resistance welding apparatus includes a welding gun having a first electrode tip serving as a first welding electrode, a second electrode tip serving as a second welding electrode, and a current branching electrode. The current branching electrode has an annular shape and is disposed in surrounding relation to the first electrode tip. The first electrode tip and the current branching electrode abut against a thinnest workpiece disposed on an outermost side of a stacked assembly that is resistance-welded by the resistance welding apparatus, and have opposite polarities to each other. When an electric current is passed from the first electrode tip to the second electrode tip and through the stacked assembly, a branched electric current flows from the first electrode tip to the current branching electrode.

Abstract: A welding system includes an engine having a rotational power output, an AC welding generator operatively connected to the rotational power output for generating an AC current, a rectifying circuit electrically connected to the AC welding generator for converting the AC current to a DC output for welding, an auxiliary power generator for supplying AC power to an auxiliary electrically powered device, and a rotational speed adjuster coupling the auxiliary power supply to the rotational power output and configured to drive the auxiliary power supply at a different rotational rate than a rotational rate of the rotational power output.

Abstract: A method of additive manufacturing, including resistance welding together contacting surfaces of adjacent substrate sheets, wherein weld nuggets overlap adjacent weld nuggets and collectively form a respective layer that bonds a portion of an entirety of an area of the respective contacting surfaces, thereby forming an assembled structure of at least three substrate sheets, wherein each substrate sheet includes a respective portion of a final structure.

Abstract: A method and an apparatus for joining first and second sheet metal parts includes a support where the first and second parts are positioned with an edge of the second part surrounded by a beading flange of the first part. A joining electrode is positioned adjacent to the beading flange and a counter-electrode is positioned adjacent to the second part. An abutment of a tong-type welding apparatus in placed in contact with the support, and the joining electrode and the abutment are urged toward one another to press or clamp the beading flange between the joining electrode and the support. An electric current is applied to the beading flange using the joining electrode and the counter-electrode to weld the parts together.

Abstract: Weld faces of electrodes for resistance spot welding are formed with a suitable area of protrusions and/or intrusions. The size, shape, and elevation or depths of the protrusions or intrusions are determined for the formation of suitable spot welds in and between metal workpieces such as aluminum or steel panels for vehicle bodies. The protrusions or intrusions are also conceived and used to form an image on at least a visible surface of the welded article to produce an attractive appearance on the surface of the welded sheet.

Abstract: The invention relates to a vehicle body structure in the region of the A-pillar and the windshield cross member, including an A-pillar on both sides of the body, wherein in the pillar construction of the A-pillar, the A-pillar has an A-pillar inner steel plate oriented approximately vertically and in the vehicle longitudinal direction. An approximately horizontal windshield cross member is connected at the ends thereof to the associated A-pillar inner steel plate by means of a welded connection. According to the invention, the windshield cross member is produced as a composite component made of an elongated aluminum beam having steel plate adapter parts that extend the aluminum beam at the ends thereof but are short in comparison to the overall beam length, and the steel plate adapter parts are connected to the associated A-pillar inner steel plate by means of the welded connection and to the aluminum beam by means of a riveted connection.

Abstract: A resistance welding device is disclosed in which one and the same operator control device can be used to flexibly operate a plurality of welding controllers simultaneously or a plurality of operator control devices can be used to flexibly operate only one and the same welding controller simultaneously.

Abstract: A system for automated assembly and welding is disclosed. The system includes a pallet for receiving incoming workpieces; a workpiece holder having a plurality of electromagnets; a handling robot configured to transport incoming workpieces from the pallet to the workpiece holder; and a controller in communication with the workpiece holder and the handling robot. The controller is configured to determine an orientation of a workpiece positioned on the workpiece holder, and to selectively adjust an activation state of one or more electromagnets of the workpiece holder based upon the orientation of the workpiece. A method of assembling and welding workpieces is also disclosed.

Abstract: A grounding system is provided for welding applications. The system comprises a pair of contacts that are brought into close grounding contact with a workpiece, and a measurement circuit coupled to the contacts. The contacts may be urged into intimate contact with the workpiece by a biasing structure that pulls the contacts tightly against the workpiece. The measurement circuit may include a center-tap transformer having a secondary coupled to a ground lead and to the contacts. A primary winding of the transformer is coupled to an oscillator that executes a measurement test. The system may provide an indication of the quality of the ground in the form of an operator perceptible notification, a digitized value, or any other suitable form.

Abstract: A welded construction according to the present invention has a first metallic member, on one surface of which a projecting portion is formed and on the other surface of which a depressed portion corresponding to the projecting portion is formed, and a second metallic member are welded together at a welded portion which includes a summit portion of the projecting portion; wherein, on at least one of the first metallic member and the second metallic member, on its opposite surface to its surface that faces the other one of the metallic members, a recessed portion is formed that is recessed from its peripheral region towards a region which corresponds to the welded portion.

Abstract: A control valve, which has a substantially cylindrical valve box and a substantially cylindrical control piston. The control valve can be arranged in a cylindrical receptacle and the control piston is arranged so as to be axially displaceable inside the valve box.

Abstract: A device is provided in which a pressing electrode (19, 105) is advanced toward a steel plate component (48, 131) to press a welding projection (4) of a shaft-shaped component (1) against the steel plate component (48, 131), so that the shaft-shaped component (1) is electric-resistance-welded to the steel plate component (48, 131). Pressing force accumulating means (22, 128) for accumulating the pressing force of the pressing electrode (19, 105) is disposed between a pressing member (17, 106) and a pressed member (18, 121). Detection means (54, 113, 3) activated when the pressing member (17, 106) is located at a predetermined position is provided to apply welding current flowing to the electrode, and pressing force adjusting means (55, 123) for adjusting the activation position of the detection means (54, 113, 3) is provided.

Abstract: This invention aims to provide a resistance welding method capable of stabilizing quality or improving efficiency of resistance welding such as spot welding. This resistance welding method comprises a calculating step of calculating resistance ratio X of a second electric resistance value R2 of workpieces to be joined in residual heat after Joule heating stops to a first electric resistance value R1 of the workpieces immediately before the Joule heating stops or vice versa (R2/R1 or R1/R2); a determining step of determining whether the resistance ratio X is equal to or greater than a threshold value Xn, and a reheating step of carrying out the Joule heating again when the resistance ratio X is smaller than the threshold value Xn. Thereby at least part of a welding portion is melted and solidified to reliably form a nugget, and a stably resistance-welded member can be provided.

Abstract: Provided is a composite nanometal paste, whose layer, when sintered in an inert gas under no load, gives a metal layer that is equal or superior in electrical conductivity and thermal conductivity to conventional lead-rich solders. The composite nanometal paste contains, as metal components, composite metal nanoparticles comprising metal cores with an average particle diameter of d (nm) and an organic coating layer formed around the circumference, and metal filler particles having an average particle diameter of D (nm), and satisfies the first relation d<D and the second relation d<100 (nm).

Abstract: A radial-flow plate heat exchanger (5) embedded in the catalytic bed of an isothermal chemical reactor (1) has heat exchange plates (10) comprising fluid passages (13) between a first metal sheet (20) and a second metal sheet (21) joined by perimeter weld seams (23) on a first surface (A) of the plate, a feeding channel (14) and a collecting channel (15) for the heat exchange fluid are formed with suitable metal sheets which are seam welded (25) directly to the opposite surface (B) of the plate, this structure allows the manufacturing of the plate (10) with an automated seam welding process, such as laser beam welding.

Abstract: A structural component is provided comprising a base member comprising at least two sidewalls and a space therebetween, the base member having a predetermined curvilinear configuration formed using hot stretch forming. The structural component comprises at least one reinforcing member linear friction welded to the at least two sidewalls so that the reinforcing member is positioned at least partially within the space between the at least two sidewalls.

Abstract: A method for manufacturing a projection weld connection between at least two parts of a workpiece, where the workpiece remains blemish free, comprising automated real-time verification of the quality of the individual weld, without use of destructive testing by analysis of data from a force sensor is disclosed. Measurements of the quality of each weld can be calculated, and real-time measurements and calculations can be used to verification of the structural integrity of the projection in the workpiece before the welding current is applied in order to avoid further damage to the workpiece. The method may be implemented in a system comprising, among other features, a displacement sensor.

Abstract: Disclosed are a resistance welding method for welding a stack of three or more works and a device therefor. A stack is formed in such that the thinnest work having the smallest thickness among the works is placed in the outermost position. The stack is held between a first welding electrode and a second welding electrode. A pressing member is brought into contact with a location of the thinnest work different from the location with which the first welding electrode is in contact, and the pressing member is caused to press the stack from the thinnest work side. In a state that the pressing force exerted on the stack by the first welding electrode and the pressing member is balanced with the pressing force exerted on the stack by the second welding electrode, current is applied between the first welding electrode and the second welding electrode.

Abstract: A system and method for using Friction Stir Spot Joining (FSSJ) to join workpieces made of Advanced High Strength Steels (AHSS), wherein a first embodiment is a FSSJ tool that has no surface features, and wherein the rate of rotation of the FSSJ tool is much higher than is used in other FSW techniques to thereby reduce torque by causing plasticization of the AHSS on a small scale, and in a second embodiment, conventional FSSJ tools can be used at conventional FSSJ speeds if the FSSJ tool is manufactured from conductive tool materials having a high hardness, and heating of the FSSJ tool and/or the workpieces enhances the ability of the FSSJ tool to functionally weld the AHSS.

Abstract: A method is taught for creating a hollow sphere that is created by joining two cylinders together that have a semispherical hollow formed in the ends being joined together, wherein a metallic reinforcing disk is inserted at an interface between the two ends of the cylinders, wherein the two cylinders and reinforcing disk are joined using friction stir welding to create an inner sphere from the two hemispherical hollows that is bisected by the metallic reinforcing disk, and wherein the joined cylinders and reinforcing disk are machined to thereby create an outer spherical surface that is centered around the inner sphere.

Abstract: A cap assembly for use in an electrochemical cell. The cap assembly includes a tab collection post, a core insert, and at least one current collecting tab connected at one end to an electrode foil in the electrochemical cell, and horizontally connected at the other end to the tab collection post and the core insert. The at least one current collecting tab is disposed between and welded with the tab collection post and the core insert. The cap assembly also includes a shock absorber disposed around the core insert.

Abstract: A method for welding two components is disclosed. In an embodiment, the method includes the following process steps. The two components are positioned such that the joining surfaces are opposite each other, at a short distance from each other. A high-frequency electrical current is conducted through the two components, heating the components at least in the region of the joining surfaces. The two components are pressed against each other such that the two joining surfaces are welded together.

Abstract: A method of monitoring and maintaining a weld cap which is executing successive resistance welds on a plurality of workpieces includes measuring a first weld indentation formed during a first resistance weld and measuring a second weld indentation formed during a second resistance weld. The measured first and second weld indentations are compared with a severe threshold. If either of the measured first or second weld indentations is greater than the severe threshold, an abnormal condition is signaled. The method may include tip dressing the weld cap based upon the signaled abnormal condition. The method may further include determining a degradation rate between the first resistance weld and the second resistance weld. The degradation rate is the time differential between the measured first and second weld indentations, and either a first or a second tip dressing schedule is chosen based upon the determined degradation rate.

Abstract: A method for machining at least one workpiece with multiple process includes providing a positioning assembly and at least two machining devices, positioning the at least one workpiece on the positioning assembly, positioning the positioning assembly on one of the at least two machining devices and machining the at least one workpiece, and transferring the positioning assembly together with the at least one workpiece on other different machining devices for undergoing different machining processes.

Abstract: A method for soldering or hybridizing two components including preparing, on opposing surfaces of the components to be welded or hybridized, a wettability surface, depositing on one of the wettability surfaces an appropriate quantity of solder material, constituting a soldering or hybridizing dot, contacting the wettability surfaces of the components with the solder material deposited, then raising the temperature of the chamber in which the components are positioned, to at least the melting point of the solder material in order to ensure the effective soldering or hybridizing of the two components together by a remelt effect. At least one of the components is in contact with a conducting track having another quantity of solder material that constitutes a sacrificial dot, having a contact area with the at least one component that is higher than that of the solder quantity that constitutes the soldering or hybridizing dot.

Abstract: In one embodiment, a method of fabricating an implantable stimulation paddle comprises: providing a sheet of conductive material coupled to a first insulative layer; laser removing portions of the conductive material to form a pattern of conductive material, the pattern of conductive material including a plurality of isolated metal traces; providing a second insulative layer over the pattern of conductive material so that the pattern of conductive material is interposed between the first and second insulative layers; and exposing portions of the metal traces to form electrodes on the paddle for delivering electrical stimulation.

Abstract: [Problem] To provide a metal connecting method and a metal connecting device to prevent a shot-circuit between the core wire and the shield portion by preventing the insulating inner coat from melting, and to surely connect the shield portion and the conductive member to each other. [Means for solving problem] The ground terminal 4 is wound around an outer periphery of the coaxial cable 3. A portion of the ground terminal 4 wound around the coaxial cable 3 is clipped between the pair of electrodes 11, 12. While the pair of electrodes 11, 12 is pressed in a direction close to each other, a current is applied to the pair of electrodes 11, 12. The current of a predetermined current value is applied for a predetermined time so that the insulating outer coat 34 is heated more than the melting point of the insulating outer coat 34, the braided wire 33 and the ground terminal 4 are connected to each other, and the insulating inner coat 32 is heated less than the melting point of the insulating inner coat 32.

Abstract: A soil reinforcing element for use in a mechanically stabilized earth structure is disclosed. The soil reinforcing element may include a pair of longitudinal wires extending substantially parallel to each other and having a connection end. A plurality of transverse wires is coupled to the pair of longitudinal wires and laterally-spaced from each other, thereby forming a welded wire gridworks. To increase the tensile capacity of the soil reinforcing element and also improve pullout valued from the backfill, the soil reinforcing element is made of positively deformed wire or bar stock. An end connector is coupled to the connection end and facilitates connection of the soil reinforcing element to a vertical facing.

Abstract: A device for the discharge of urea solution into an exhaust gas conduit (40) includes an injection nozzle (2) with a conduit connection (14) for the supply of urea solution, and a nozzle head which is conductively connected thereto. The urea solution may be supplied to an exhaust gas flow in a finely distributed manner by way of the nozzle head. Furthermore, the device includes a receiver (42), which surrounds an opening (46) in the exhaust gas conduit wall (44) and which is designed for the tight bearing of the nozzle head and for the releasable fastening of the injection nozzle (2). Moreover, a spring is provided for the non-positive fit bearing of the nozzle head in the receiver (42).

Abstract: Methods and devices for control for an automated welding system are provided. Disclosed control methods may include receiving a data set including one or more features of a joint to be welded and receiving a weld procedure for the joint to be welded. The weld procedure for the joint is determined based on a sample virtual weld performed by an operator, a stored procedure developed for a substantially similar weld joint, or a combination thereof. The method may further include determining one or more desired changes to the weld procedure based on the received features of the joint to be welded and generating an updated weld procedure by altering one or more parameters of the received weld procedure in accordance with the one or more desired changes, wherein the one or more parameters are included within a predetermined allowable data set.

Abstract: Disclosed is a bonding method for dissimilar materials made from metals and its resulting structures. The materials to be bonded are formed by layering three or more sheets such that a dissimilar material interface and a same material interface are formed. A first current is conducted between a three-sheet layered plate material wherein an aluminum alloy plate, a zinc plated steel plate and a bare steel plate, for example, are layered in order. A nugget is formed in an interface between the zinc plated steel plate and the bare steel plate, which are the same materials. Then, a second current greater than the first current is conducted, and a nugget is formed in an interface between the aluminum alloy plate and the zinc plated steel plate.

Abstract: A method for monitoring the presence of an adhesive between two metal workpieces includes measuring the depth of indentation made by electric resistance weld electrodes by measuring the advance of the weld electrodes, and comparing the measured depth of indentation with the depth of indentation that is known to occur when the presence of the adhesive between the metal workpieces minimizes the shunting of weld current and thereby affects the depth of indentation. If the adhesive is absent, a supplemental electric resistance weld is made to compensate for the absent adhesive. The invention is applicable to both adhesive bonding, where only adhesive is used to attach the workpieces, and weldbonding, where an electric resistance weld is made atop a layer of adhesive.

Abstract: A screen joint assembly includes a joint comprising a ring portion and a lip portion protruding from the ring. A first particle screen is connected to a first side of the joint and a second particle screen connected to a second side of the joint. The lip portion may be welded to form a weld seam that interconnects the first and second particle screens.

Abstract: In one embodiment, a method of fabricating an implantable pulse generator, comprises: providing a lead body including a plurality of conductors, the plurality of conductors being enclosed in insulative material along a first length of the conductors, a second length of the conductors being exposed from the insulative material; providing a tubular structure over the lead body with the plurality of conductors extending through the tubular structure; providing a feedthrough assembly including a plurality of feedthrough pins surrounded by insulator material, the feedthrough assembly further comprising a ferrule extending about an outer surface of the feedthrough assembly; attaching the plurality of conductors to the plurality of feedthrough pins; welding the ferrule of the feedthrough assembly to the tubular structure to form an intermediate assembly; welding the intermediate assembly to one or more housing components of the implantable pulse generator to hermetically seal the implantable pulse generator; and pro

Abstract: An apparatus for connecting an earthen formation to a concrete facing of a mechanically stabilized earth (MSE) structure, and a method of manufacturing the same. A one-piece, flat, plate-like connector has a stem and a tab, wherein the stem is resistance welded to a soil reinforcing element embedded within the earthen formation. The tab is connected to a facing anchor attached to the concrete facing. The stem of the plate connector has grooves formed in its opposing sides and longitudinal channels to increase the strength of the resistance weld.

Abstract: The present invention consists of developing a technology with different processes to realize an optimal solar approach using a solar concentrator where distance screws are used that, when moving, allow the positioning of the mirrors whereby the reflected solar beam is directed to a focal point; the advantage of these processes is that each movement of the screws involves adjusting the position of all the neighboring mirrors, which allow a perfect alignment and adjustment of the mirrors.

Abstract: A method for operating a welding device (1), wherein the welding device has at least one welding electrode (4), which is operated with at least one variable electrical reference value and wherein this electrical reference value is controlled by a control device (6), wherein the control of the electrical reference value takes place with allowance being made for a set of reference data (25) that is characteristic of a welding operation to be carried out. According to the invention, the set of reference data (25) is determined on the basis of at least one set of raw data (23a, 23b, 23c, 23d), wherein this set of raw data (23a, 23b, 23c, 23d) is characteristic of the welding operation to be carried out.

Abstract: A workpiece arrangement includes at least two join regions of at least one workpiece that are joined together by a material-to-material connection seam. The material-to-material connection seam covers only a portion of a first of the at least two join regions. A thermal insulation device is disposed in an area of the material-to-material connection seam and corresponds to the first of the at least two join regions.

Abstract: A method and apparatus for providing welding-type power is disclosed and includes an RTC module and/or a non-volatile memory.

Abstract: A terminal and electrical contact for a pair of leads of an electrical component is provided, the terminal having a pair of terminals each comprising a planar member comprising a conductive material that surrounds an opening in the planar member; and wherein one of the pair of leads is welded to one of the pair of terminals such that the lead traverses the opening and is welded to the terminal at a portion of the terminal adjacent to the opening and the other one of the pair of leads is welded to the other one of the pair of terminals such that the lead traverses the opening and is welded to the terminal at a portion of the other one of the pair of terminals adjacent to the opening, wherein the opening and the planar member are configured such that a high resistance zone is created at the portion of the terminal adjacent to the opening.

Abstract: A retroreflective sheeting (10) comprising a cube layer (20) having a front light-receiving surface (30) and a rear retroreflecting surface (32), and a metallic layer (22) covering the rear retroreflecting surface (32). The rear surface (32) comprises an array of retroreflective elements (34) and diffusing patches (36) within such array (without retroreflective elements (34)). The metallic layer (22) covers the retroreflective elements (34) and the diffusing patches (36), whereby diffusing patches (36) scatter incoming light increasing daytime brightness to a desired level.

Abstract: The present application discloses an apparatus for consolidation welding of an electrical conductor, in particular to an electrical terminal, preferably for resistance-monitored circuitry in a motor vehicle, having a bottom welding tool, on which a conductor section to be consolidated can be arranged, as well as three movable welding tools, whereby with a movable welding tool, which has two translational degrees of freedom, a width of the conductor section to be consolidated can be variably adjusted with reference to the bottom welding tool, and the other two movable welding tools can be moved in such a way that they seal off a compression chamber delimited by the width of the conductor section to be consolidated in a direction of its perimeter.

Abstract: There is provided a chip-type electric double layer capacitor comprising: a resin case having a housing space provided therein and formed of insulating resin and first and second external terminals inserted into the resin case by insert injection molding. Each of the external terminals has a first portion exposed to an outer surface of the resin case for external contact and a second portion exposed to an inner surface of the housing space for internal contact. a sealing portion includes a groove portion provided in the resin case along a circumference of at least one of the first and second external terminals and a resin filling the groove portion. An electric double layer capacitor cell is mounted in the housing space and electrically connected to the second portion of the first and second external terminals.

Abstract: The workpiece-contacting surface of the spot welding electrode may be suitably modified to incorporate a desired shape or form, generally comprising a depressed region outlining a recognizable shape, to form aesthetically-pleasing or functional features in the surface of a workpiece during resistance spot welding. Methods for creating the desired form in the spot welding electrode including abrasion, upsetting, and electrical discharge machining are disclosed. Preferably the electrode face is shaped and subsequently redressed during welding operations at the welding station.

Abstract: A handheld welder is provided for welding together parts of a workpiece. The welder may include a pair of three-part clamps with spring-loading so as to temporarily hold the parts of the workpiece in place before tightening the clamps. A housing can be provided for housing batteries or at least part of a power cord and for structurally supporting a heater element during welding. The housing can include radially-extending screws that are slidably provided within slots of a sleeve to allow the housing to axially move within the sleeve, so that the heater element may be at least partially retracted into the sleeve once the welding operation is completed.

Abstract: A method for manufacturing a coreless armature, which can prevent a short circuit of adjacent terminal layers when resistance-welding the terminal layers, is provided. In a method for manufacturing a coreless armature, terminals 5 of the conducting bands 3 provided to each coil base 1 are stacked to form a terminal layer 23, a welding rod 21 is pressed against a terminal positioned on an outermost periphery so as to interpose the terminal layer 23 between coil jigs 9a and 9b and the welding rod 21, and an electric current is applied thereto, thereby connecting each terminal 5 of the terminal layer 23 by way of resistance welding, in which an insulating material 25 is arranged between terminal layers 23 adjacent in a circumferential direction to resistance-weld the terminal layers 23.

Abstract: A welding head for the formation of a metal mesh includes longitudinal wires (12) and transverse wires (13), having at least a feed unit (16) able to feed step-wise a plurality of longitudinal wires (12), and a welding unit (17) by which the longitudinal wires (12) are welded to corresponding transverse wires (13). The welding unit (17) includes at least two electrodes (19,20) selectively movable between a first feed position and a second welding position. The welding head includes at least a movement member (22) to move the first electrode (19) between the first and the second position, first sensor members (25) associated with the movement member (22) and configured to detect the position of the first electrode (19) with respect to the two wires (12,13) and/or second sensor members (30,31) to detect the working pressure of the first electrode (19).

Abstract: A method for weldbonding together metal sheets includes applying adhesive on the surface of a first sheet and placing a second sheet atop the first sheet. The sheets are heated at a selected location to a high temperature forming a metallic weld nugget between the first sheet and the second sheet. The adhesive may be a heat curable adhesive that is cured by the heat, or the adhesive may be heated at ambient temperatures. One or both of the sheets is then cooled in the area surrounding the selected location of heating so that the high temperature needed to created the metallic weld nugget is prevented from transferring so far beyond the selected location as to overheat the adhesive layer and thereby degrade the quality of the adhesive bond.

Abstract: Spot welding system including a welding gun with an electrode pair actuated by a servo-motor, a robot carrying the welding gun or objective workpieces and operating to change an relative positions and orientations of the welding gun and an workpieces, and a gun motion controller controlling the servo-motor to actuate the electrode pair. The gun motion controller includes a motion commanding section outputting motion commands to the servo-motor in accordance with a speed set-value designating a closing speed of the electrode pair, and a set-value adjusting section automatically adjusting the speed set-value to an appropriate value.

Abstract: A seam welding apparatus and a seam welding method perform a seaming process on workpieces of various shapes having flange sections, by preventing a welding track formed by upper and lower rotary electrodes from becoming displaced from a welding reference line established on the flange section. The seam welding apparatus includes two rotary electrodes for gripping the flange section therebetween while seam-welding the flange section, a support for synchronizing movements of the two rotary electrodes with each other in a widthwise direction of the flange section, a turning mechanism for pressing at least one of the two rotary electrodes toward the workpiece body, a roller that abuts against an end face of the flange section, and roller adjusting means for positionally adjusting the roller.