GB710464A - Electromagnetic hammer - Google Patents

Abstract

710,464. Power hammers. ELMEG ELEKTROMECHANIK GES. April 8, 1952 [April 21, 1951], No. 8955/52. Class 83 (4). An electromagnetic hammer comprising a stationary support with a base portion for the workpiece, and a hammer assembly including an armature having resilient means for returning it when the coil is de-energized is characterized in that the complete hammer assembly is carried by a plate member slidably mounted on said support and manually adjustable to bring the hammer assembly nearer to or further away from the base portion. In an embodiment a support member 1 has a base 9 for a work-piece or die and carries a plate member 3 vertically adjustable by a screw 11. Bolted to the plate 3 is a coil 2 through which extends an armature 4 the lower end of which carries a tool the upper end being connected to a bar 5. Pins 6 mounted on the coil pass through openings in the bar 5 and are connected at their upper ends to a crosshead member. The bar 5 is urged towards the cross-head member by springs 7. When the coil is energized the armature is forcibly moved towards the base to effect the hammering. The coil may be enclosed and liquid cooled or its casing 13 may be provided with cooling fins 14. In a further embodiment the hammer may be provided with two coils 18 and 19 in order to increase the hammer force. These are bolted to a common vertically adjustable plate 17 an armature having portions 21, 21<SP>1</SP>, 20 and 25 is mounted for movement through the coils and is urged away from the base by springs 24 surrounding pins 23. The distance between the coils is at least as great as the axial length of either of the coils in order to prevent interference. The portions 20, 21 of the armature are of magnetizable ferrous or non-ferrous material and the portions 21' and 25 are of non-magnetizable material, such as brass or bronze. The coils may be connected in series or parallel and they may be energized simultaneously or alternatively.