Abstract In power presses such as are used for stamping sheet metal and the like, the inertia forces of the reciprocating slide of the press and its attached parts set up very heavy and objectionable vibrations, particularly in high speed presses. The present invention provides primary and secondary counterweights. The primary counterweights rotate with the crankshaft or eccentric shaft of the press but with the center of gravity of the counterweight moving in a direction opposite to the direction of movement of the slide to neutralize at least a portion of the inertia forces of the slide and its connected parts. The secondary counterweight rotates opposite to the first counterweight but with its center of gravity moving in the same direction with respect to the vertical, so that the second counterweight has a cumulative effect with respect to the primary counterweight in neutralizing vertical inertia forces but has a subtractive effect with respect to lateral inertia forces produced by rotation of the primary counterweight.
In a power press having a frame including a bed, a slide reciprocable with respect to said bed and connectible with a movable die member to effect working strokes thereof, a continuously rotating shaft having eccentric drive means and means connecting the same to said slide for reciprocating the same; first counterweight means rotatable with said drive shaft and having its center of gravity opposite to that of said eccentric drive means whereby said first counter-weight means moves in opposition to the movement of said slide, and second counterweight means synchronized with said first counterweight means to rotate continuously at the same speed but in the opposite direction, the center of gravity of said second counterweight means being offset from its axis of rotation in the same direction as that of the first counterweight means with respect to the direction of the slide, whereby said two counterweight means move in unison with respect to the direction of said slide but oppositely with respect to a direction at right angles thereto.
Claim 2
Dependent Claim
170 words
In a power press having a frame including a bed, a slide reciprocable with respect to said bed and connectible with a movable die member to effect working strokes thereof, a continuously rotating shaft having eccentric drive means and means connecting the same to said slide for reciprocating the same; first counterweight means rotatable with said drive shaft and having its center of gravity opposite to that of said eccentric drive means whereby said first counter-weight means moves in opposition to the movement of said slide, and second counterweight means synchronized with said first counterweight means to rotate continuously at the same speed but in the opposite direction, the center of gravity of said second counterweight means being offset from its axis of rotation in the same direction as that of the first counterweight means with respect to the direction of the slide, whereby said two counterweight means move in unison with respect to the direction of said slide but oppositely with respect to a direction at right angles thereto.
Claim 3
Dependent Claim
19 words
Apparatus according to claim 1 wherein said first counterweight means is mounted on said drive shaft for rotation therewith.
Claim 4
Dependent Claim
44 words
Apparatus according to claim 1 including a countershaft and transmission means connecting the same to said drive shaft for rotation at a one to one ratio therewith but in the opposite direction, said second counterweight means being mounted on said countershaft for rotation therewith.
Claim 5
Dependent Claim
44 words
Apparatus according to claim 2 including a countershaft and transmission means connecting the same to said drive shaft for rotation at a one to one ratio therewith but in the opposite direction, said second counterweight means being mounted on said countershaft for rotation therewith.