US 4,398,674 AGranted

Hydraulically actuated jam release system for a jaw type crushing apparatus

OwnerGeorge H. Dremanninventor

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Abstract

A hydraulically actuated jam release system for a jaw type rock crusher wherein a massive, mechanically rigid retracting plate is disposed behind the crusher's stationary jaw to engage the entire width of the jaw to hold the stationary jaw in its operative position. Mechanical locking pins are hydraulically actuated by vertical hydraulic cylinders to mechanically lock the retracting plate in its forward position, and separate horizontal hydraulic retracting cylinders are provided to retract the retracting plate when the mechanical locking pins are disengaged therefrom, and to return the retracting plate to its forward position after the non-crushable material has been released from the crushing chamber of the crusher. The entire hydraulic system for the jam release is hydraulically operated through a series of suitable hydraulic valves preferably located at a central control station. It is an important aspect of the disclosure that once the retracting plate is mechanically locked by the locking pins, the stationary jaw does not require hydraulic pressure.

Claims19

Dependent claims

In a jaw type crushing apparatus having a stationary frame, a crushing chamber defined by a stationary jaw and an opposing swing jaw downwardly hinged from hinge points in said frame, and means for reciprocating said swing jaw, a hydraulically actuated jam release system comprising

mechanically rigid, substantially horizontal retracting means having a forward end and a rearward end and at least one locking pin opening intermediate said forward and rearward ends, said retracting means being slidably disposed in said frame behind the lower end of said stationary jaw to that the forward end of said retracting means engages the lower end of said stationary jaw,
hold back means for holding said stationary jaw against the forward end of said retracting means whereby the stationary position of said stationary jaw is governed by the horizontal position of said retracting means,
at least one locking pin assembly having a locking pin substantially vertically disposed over said horizontal retracting means, said locking pin being in alignment with the locking pin opening in said retracting means when said retracting means is positioned in its substantially full forward position,
first hydraulic means for controllably raising and lowering said vertical locking pin to, respectively, disengage and engage the locking pin opening in said retracting means,
second hydraulic reciprocating means for controllably moving said retracting means horizontally in a forward and rearward direction of travel, and
valve means for actuating said first and second hydraulic reciprocating means to permit sequencing the movement of said horizontal retracting means and said vertically disposed locking pin to open and close said stationary jaw.

3 more elements

two opposed top and bottom strongback members having vertical rear walls and extending transversely of said frame behind said stationary jaw and forming a guide slot therebetween, said strongback members forming a portion of said stationary frame and having at least two pairs of laterally spaced, vertically aligned guide holes therein,
a mechanically rigid, substantially horizontal retracting plate having a forward end and a rearward end and at least two laterally spaced locking pin openings intermediate said forward and rearward ends, said retracting plate being slidably disposed between the guide slot formed by said opposed strongback members behind the lower end of said stationary jam so that the forward end of said retracting plate engages the lower end of said stationary jaw,
hold back means for holding said stationary jaw against the forward end of said retracting means whereby the stationary position of said stationary jaw is governed by the horizontal position of said retracting plate,
at least two laterally spaced locking pin assemblies disposed over the top strongback member of said opposed strongback members, each of said assemblies having a locking pin substantially vertically disposed over and in alignment with one of the pair of guide holes in said strongback members, each of said guide hold pairs in said strongback members being positioned so as to be in alignment with one of the locking pin openings in said retracting plate when said retracting plate is positioned in its substantially full forward position,
said locking pin openings in said retracting plate being slightly elongated in the direction of travel of said retracting plate,
a hydraulic lifting cylinder vertically secured to the top of each of said locking pin assemblies for controllably raising and lowering said vertical locking pins of said locking pin assemblies to, respectively, disengage and engage the locking pin openings in said retracting plate,
at least two laterally spaced and horizontally disposed hydraulic retracting cylinders secured to the rearwalls of said opposed strongback members behind said retracting plate for controllably moving said retracting plate horizontally in a forward and rearward direction of travel,
a spring coupler for joining the end of the hydraulic rams of each of said hydraulic retracting cylinders to the rearward end of said retracting plate, said spring coupler being disposed and adapted to react against the rear walls of said opposed strong back member when the retracting plate is in a substantially full forward position whereby, when said retracting plate is in a substantially full forward position, said plate will be biased in a rearward direction against said locking pins when said locking pins are engaged in said locking pin openings of said retracting plate, and
valve means for actuating said lifting and retracting cylinders to permit sequencing the movement of said horizontal retracting plate and vertical locking pins to open and close said stationary jaw.

6 more elements

Dependencies are inferred from the claim text.