Abstract: A method for treating or pre-treating parts, profiles, strips, or wires comprising surfaces of aluminum, or other metal surfaces with an acidic, aqueous solution containing fluoride and phosphate.

Abstract: The invention relates to a method for treating or pre-treating parts, profiles, strips, or wires comprising surfaces of aluminium, or alloys containing aluminium optionally in the presence of surfaces consisting of other metals or alloys with an acidic, aqueous solution containing fluoride and phosphate. Said method is characterised in that the fluoride is present at least partially as a free fluoride in the solution and that in the bath of phosphating solution, the content of free fluoride is maintained within a concentration range of between 5 and 500 mg/l Ffree and that of aluminium is maintained within a concentration range that is less than or equal to 100 mg/l Al ions (including complexed Al). To achieve this, increases in the aluminium content are reduced to contents of less than or equal to 100 mg/l Al ions in the bath, using a precipitation container outside the phosphating bath by circulating the phosphating solution from the phosphating bath to the precipitation container and vice versa.

Abstract: A lubricating device for a revolving lock stitch shuttle of machines such as sewing and embroidering machines comprises a shuttle body which has a hub portion which surrounds its associated shuttle arbor and which lies adjacent a bearing mounting for the arbor. The hub portion is hollow and defines a lubricating oil chamber between it and the associated bearing and a gap between the shuttle hub portion and the associated bearing is bridged by a fixed ring member which is carried on a bracket which is secured to the bearing. The ring member has an opening therethrough providing an access for a nozzle tube for feeding oil from an external reservoir to the hub recess from when the oil is advanced by the centrifugal force of the rotation of the shuttle to the periphery of the shuttle.

Abstract: An apparatus for securing and releasing an embroidery frame to a clamping rail comprises a connecting piece guide with a bore therethrough and a rod extending through the bore and extending along the clamping rail and guided in the bore for movement in the connecting piece guide bore. The rod carries a pressure piece which is movable with the rod. The clamping rail has a plurality of spaced apart embroidery frame pin receiving openings and embroidery frames are secured by inserting the pins of the frame into the openings. Each pin has a side with a cutout and each pin receiving opening has a fixed spacer plate adjacent the opening which carries a resilient holder which may be engaged in a cutout of the embroidery frame pin when it is inserted into the associated opening.

Abstract: A feed drive for the work holder of a zig-zag stitch group sewing machine comprises a rotatable cam plate and a work holder which is engaged with the plate and moved thereby within a rectilinear guide arranged adjacent the head portion of the sewing machine. The work holder is located adjacent the needle and it includes a driver plate which extends below the sewing machine arm portion and grips the workpiece from above. The cam plate is arranged in a standard of the machine and the work holder is driven by engagement of a sensing element in a groove of the cam plate which is connected to the work holder through a lever drive acting on a rotatable shaft arranged below the arm of the machine and connected with a crank and a link with a slide carrying the work holder which is disposed in a guide. The construction includes a seating for the workpiece which is movable parallel to the guide and is coupled with the driving plate.

Abstract: A feed drive for a stitch group sewing machine includes a cam plate serving to drive a work clamp. The cam plate is connected to a controllable clutch driven from the drive motor of the sewing machine. In order to keep the stitch length constant at varying lengths of the stitch group, the output speed of the clutch is controllable by a control device as a function of the rotational speed of the sewing machine of the transmission ratio of a gearing between the cam plate and the work clamp which determines the length of the stitch group, and of the adjusted stitch length. The stitch group to be sewn may be divided into two sections having their stitch lengths variable independently of each other, by providing that a switch responsive to a partial revolution of the cam plate corresponding to the length of the first section, alternately connects one of two potentiometers which determine the stitch length, to the control circuit of the clutch.

Abstract: The cloth clamp comprises a pivot arm provided with a clamp foot, which arm can automatically assume a closed position through a toggle lever drive, a setting lever connected therewith, and an extension spring acting on the setting lever counter to the force of a leaf spring packet acting on the toggle lever drive. An actuating mechanism is needed only for opening the cloth clamp.

Abstract: A feed drive for a stitch group sewing machine includes a cam plate serving to drive a cloth clamp and it is connected with a separate motor. In order to keep the stitch length constant at varying length of the stitch group, the motor speed is controllable by a control device as a function of the rotational speed of the sewing machine, of the transmission ratio of a gearing between cam plate and cloth clamp which determines the length of the stitch group, and of the adjusted stitch length. The stitch group to be sewn can be divided into two sections with a stitch length variable independently of each other, in that a path-dependent switch operable after a partial revolution of the cam plate corresponding to the length of the first section alternately connects one of two potentiometers which determine the stitch length, with the motor control circuit.