A stitcher (1) for connecting an end portion of an outgoing metal strip to a starting portion of an incoming metal strip for a continuously operated strip processing system comprises a first punching tool (20), which is designed to connect metal strips having a first thickness range and/or strength range to one another, and a second punching tool (30), which is designed to connect metal strips having a second thickness range and/or strength range to one another. Both thickness ranges and/or strength ranges are different from one another.

The invention provides a composite metal sheet produced by joining two metal sheets together, comprising: a projection formed by cutting the two metal sheets along a cutting line and pressing an area surrounded by the cutting line and a reference line in the two metal sheets, with the two metal sheets overlapping each other, with the reference line remaining uncut, with the cutting line extending from and communicating with both terminals of the reference line while forming a predetermined shape together with the reference line, and with the projection formed at one portion of the area in response to pressure applied to the area; hole generated by forming the projection in the two metal sheets; and a joint disposed between an outer peripheral cutting face of the projection and an inner peripheral cutting face of the hole.

A joining method is a method of joining a plate set composed by a plurality of stacked plate members including a first plate member and a second plate member by using a tapping screw. When the tapping screw is advanced into the plate set while the tapping screw is rotated in a state of applying a pressure onto the plate set so as to form through-holes in the first plate member and the second plate member, a first pressure applied onto the tapping screw is reduced down to a second pressure at the time when the tapping screw penetrates the first plate member.

Embodiments of connectors for joining metal sheets, and methods of using the same, are described.

A metal fastening or joining apparatus is provided. In another aspect, a single piece die guard includes an integral die shield section and an integral retainer section, wherein a die anvil can be removed, and the die shield section has a low height and a small lateral square width. A further aspect employs a generally square peripheral shape for a die shield within which is an anvil and movable die blades, which are operable to fasten or join sheet metal workpieces together in an interlocking manner. In still another aspect, a projecting and/or peripheral orientation structure is on a backside of a workpiece fastening die assembly which allows for anvil reorientation without the need to also reorient a laterally surrounding die shield and retainer.

A metal fastening or joining apparatus is provided. In another aspect, a single piece die guard includes an integral die shield section and an integral retainer section, wherein a die anvil can be removed, and the die shield section has a low height and a small lateral square width. A further aspect employs a generally square peripheral shape for a die shield within which is an anvil and movable die blades, which are operable to fasten or join sheet metal workpieces together in an interlocking manner. In still another aspect, a projecting and/or peripheral orientation structure is on a backside of a workpiece fastening die assembly which allows for anvil reorientation without the need to also reorient a laterally surrounding die shield and retainer.

A method for driving a piercing element includes: preparing a plate material, the piercing element, a preceding punch, and a die; arranging the plate material on a hole portion of the die; arranging the piercing element and the preceding punch in order downward from above on the plate material and on a position corresponding to the hole portion; punching the plate material via the preceding punch by pressing the piercing element downward; dropping a punched piece downward from the hole portion; following the punching of the plate material, driving the piercing element to be embedded in the plate material and causing the plate material to bite a constricted portion; and dropping the preceding punch downward from the hole portion.

A pneumatic tool for joining steel decking includes a pneumatic actuator assembly which drives a push rod. The push rod is coupled to a linkage assembly comprising a rocker link having one end rotatably coupled to the frame of the pneumatic tool, a punch arm having one end rotatably coupled to the frame, and a coupler link rotatably coupled to both the rocker link and the punch arm. At the bottom of the pneumatic tool, a punching mechanism is formed by a stationary die affixed to the frame and a movable jaw with a punch provided at the end of the punch arm. An operator may use a trigger mechanism to release a flow of pressurized air into the actuator assembly, thereby driving the push rod out of the housing of the actuator assembly. The end of the push rod is coupled to both the rocker link and the coupler link, so linear movement of the push rod out of the housing causes the rocker link to rotate about a joint link with the frame of the pneumatic tool, thereby driving the coupler link toward the punch arm. The punch arm rotates about a joint link with the frame of the pneumatic tool, thereby causing the punch to rotate about the joint link and mate with the fixed die. The punching mechanism may include four punch projections to simultaneously form four v-shaped cuts in the material positioned between the punch and the die.

A joining method is a method of joining a plate set composed by a plurality of stacked plate members including a first plate member and a second plate member by using a tapping screw. When the tapping screw is advanced into the plate set while the tapping screw is rotated in a state of applying a pressure onto the plate set so as to form through-holes in the first plate member and the second plate member, a first pressure applied onto the tapping screw is reduced down to a second pressure at the time when the tapping screw penetrates the first plate member.

A joining method is a method of joining a plate set composed by a plurality of stacked plate members including a first plate member and a second plate member by using a tapping screw. When the tapping screw is advanced into the plate set while the tapping screw is rotated in a state of applying a pressure onto the plate set so as to form through-holes in the first plate member and the second plate member, a first pressure applied onto the tapping screw is reduced down to a second pressure at the time when the tapping screw penetrates the first plate member.