Spring deflection control assembly

#During operation of a press assembly, one or more springs may be utilized to provide a controlled return pressure to a punch to return the punch to its starting position at the end of a stroke. Referring generally to the figures, various embodiments of a spring assembly enhancing the life of the springs and thereby minimizing maintenance and costs are described.

#When press assemblies are operated, the force, rate, and frequency at which the press assembly is run often results in spring fatigue, with some or all of the springs fracturing or failing. In such situations, running of the press assembly has to be halted and production must be stopped so that the press assembly can be disassembled and the springs replaced.

#In order to minimize the disruption to the operation of the press assembly, which can be costly owing to the down time required to replace the springs, in some press assemblies special, custom ordered springs may be utilized. Such custom order springs may have a longer lifespan than standard, commercial springs. However, such custom springs are often significantly more expensive that standard springs, and may be difficult to replace once the springs are worn.

#This application will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements in which:

#FIG. 1A shows a spring assembly in an initial or rest position attached to a representative press assembly according to an exemplary embodiment;

#FIG. 1B shows the spring and press assembly of FIG. 1A during use according to an exemplary embodiment;

#Shown in FIGS. 1A and 1B is one embodiment of a reduced maintenance spring assembly 1 configured to extend the lifespan of springs 10. Spring assembly 1 includes a housing 50 having a housing cavity 51 in which one or more springs 10 are supported. The lower ends of springs 10 may be positioned within one or more sleeves 11 which are spaced about and attached to a riser 19 extending through housing 50.

#Attached at the upper end of springs 10 is lower piston 12. The inner circumference of lower piston 12 surrounds the outer surface of riser 19. In some embodiments, the outer circumference of lower piston 12 is surrounded by an inner surface of housing 50. As shown in FIGS. 1A and 1B, in some embodiments the outer circumference of lower piston 12 is surrounded by an inner surface of flow inset 60 (discussed in detail below). Lower piston 12 may include one or more seals (e.g. O-rings, oil seals, lip seals, etc.) to provide a fluid tight seal between lower piston 12 and the other components of spring assembly 1.

#Positioned within upper opening 52 of housing cavity 51 is upper piston 14 having stem portion 15 and head portion 16. As illustrated in the embodiment of FIGS. 1A and 1B, the diameter of stem portion 15 is less than the diameter of head portion 16. The increased diameter of head portion 16 relative to stem portion 15 limits the upward travel of upper piston 14 during operation of the press assembly 100 and/or spring assembly 1.