The present invention relates to jaw crushers for crushing aggregate material and having a stationary crushing jaw and a moveable crushing jaw. More specifically, the present invention relates to an improved device for securing the stationary jaw to the frame of the jaw crusher.
A typical jaw crusher includes a stationary jaw and a moveable jaw spaced to define a crushing chamber in between. Aggregate material is fed into the crushing chamber and is crushed by cooperating corrugations on the face of each of the jaws as the moveable jaw is moved repeatedly toward and away from the stationary jaw.
The jaws experience tremendous forces during operation of the crusher, and it is thus important that the stationary jaw be firmly secured to the crusher frame during operation. For example, due to the angle between the moveable jaw and the stationary jaw, the moveable jaw repeatedly applies a cyclic, upward force against the stationary jaw. Any undesired movement of the stationary jaw leads to excess wear and tear, increased down time, and hence increased operational cost of the crusher. It is thus critical that the stationary jaw be firmly secured against any up and down movement.
The tremendous forces against the jaw faces also causes the jaw faces to wear much faster than the remaining crusher components. Moreover, because of the angle between the stationary jaw and the moveable jaw alluded to above, the bottom portion of the jaw face tends to wear faster than the top portion of the jaw face. Consequently, the face of the stationary jaw is symmetrical, and the stationary jaw is removable, so that jaw can be removed, rotated, and re-installed so that the life of the jaw is effectively doubled. Accordingly, it is important that the jaws be easily attachable and removable from the crusher frame.
The crusher frame typically includes a top cross member and a bottom cross member, while the jaw includes a top lug positioned to overlie the top cross member and bottom lug positioned to underlie the bottom cross member. Traditional practice has been to insert shims between the top lug and the top cross member to draw the jaw upwardly, such that the bottom lug is wedged against the bottom cross member, thus securing the jaw to the frame. The shims were then welded in place.
Unfortunately, the use of shims, which must be sized in discrete sizes, makes it difficult to find the right size shim to exert the desired amount of upward force against the jaw. Moreover, because the shims must be welded in place and then cut away in order to tighten remove, replace, and/or flip the jaw, access must be gained to the middle of the crusher. Gaining such access is often difficult, time consuming, and hence expensive, as other components such as bypass chutes or conveying equipment is often in the way. Moreover, the repeated welding, cutting, and re-welding of the shims often damages the crusher frame.
A device for securing the stationary jaw to the frame of a jaw crusher according to the present invention provides better, more positive securement of the jaw to the frame, faster and easier installation and removal of the stationary jaw, lowers operating costs, and/or prolongs the service life of the stationary jaw.
According to one aspect of the invention, a jaw crusher includes a frame having top and bottom spaced apart cross members, a stationary jaw, and a threaded draw rod having a pair of inwardly moveable wedge members. The stationary jaw includes a top edge, a bottom edge, and a pair of interconnecting sides, and further includes a top lug adjacent the top edge and a bottom lug adjacent the bottom edge. The top lug is adapted for placement adjacent the frame top cross member, and the bottom lug is adapted for placement adjacent the frame bottom cross member. The draw rod is disposed such that the wedge members are positioned to engage the jaw top lug and the frame top cross member. Accordingly, in response to inward movement of the wedge members, the stationary jaw is progressively more firmly secured to the frame, thereby preventing undesired movement of the stationary jaw during operation of the crusher.
In further accordance with a preferred embodiment of the invention, the top and bottom cross members are spaced apart a first distance, and the stationary jaw top and bottom lugs are spaced apart a second distance, with the second distance being slightly greater than the first distance. The draw rod preferably includes a pair of ends and a nut on each draw rod end for moving the wedge members inwardly. The frame may include a pair of opposing sidewalls, each of which may include an access opening, such that the draw rod ends are accessible through the access openings.
Each wedge member may include a bore, with the draw rod extending through each wedge member bore. Each wedge member bore may include an outer threaded portion, with the outer threaded portion being accessible upon the removal of the draw rod and being adapted for connection to a pulling tool. The pulling tool may be used to withdraw each wedge member through its adjacent access opening.
The frame top cross member includes a pair of tapered outer ends, and each wedge member may be also be tapered to complement the taper of the cross member outer ends. Preferably, the top cross member outer ends and the wedge members are tapered at an angle of approximately 8 degrees. The outer end of the top cross member may define a longitudinal track, and each of the wedge members may be adapted to slidably engage the adjacent longitudinal track. Each longitudinal track may be defined in part by a pair of upwardly extending flanges, and each wedge member may include a key sized to be received between the flanges of the adjacent track, such that threaded nuts applied to the opposing ends of the draw rod may draw each wedge member inwardly along the longitudinal track. Preferably, the upwardly facing surface of each top cross member outer end is sloped downwardly toward its adjacent side, so that upon inward movement of the wedge members the wedge members apply an upward force to the jaw top lug, thereby upwardly forcing the jaw bottom lug against the frame bottom cross member.
According to another aspect of the invention, on a jaw crusher having a frame, a stationary jaw and a moveable jaw, a device is provided for securing the stationary jaw to the frame. The device comprises top and bottom spaced apart cross members carried by the frame, with the stationary jaw having a top edge having a top lug, a bottom edge having a bottom lug, and a pair of interconnecting sides. The top and bottom lugs are adapted to engage the top and bottom cross members. A transversely oriented securement mechanism is provided which engages one of the stationary jaw lugs and an adjacent one of the frame cross members. The securement mechanism is adapted to apply a progressively greater upward force to the stationary jaw, thereby firmly securing the stationary jaw to the frame.
According to yet another aspect of the invention, on a jaw crusher having a frame, a pair of jaw members, and a crushing chamber defined between the pair of jaw members, a device for securing one of the jaw members to the frame comprises a pair spaced apart cross members mounted to the frame and extending between opposing sides thereof, with the cross members being spaced apart by a first distance. The one jaw member includes a top edge having a top mounting lug and a bottom edge having a bottom mounting lug, with the top mounting lug and the bottom mounting lug being spaced apart by a second distance greater than the first distance to thereby define a gap between one of the mounting lugs and an adjacent one of the cross members. A draw rod having a pair of wedge members is provided and is disposed such that the wedge members are positioned in the gap so as to engage the one jaw mounting lug and the adjacent one frame cross member. An actuating member is mounted to the draw rod adjacent each of the wedge members, with each actuating member being adapted for inward movement along the draw rod to thereby apply an inward force on the adjacent wedge member. Accordingly, upon inward movement of the wedge members the stationary jaw is wedged tightly against the frame.
According to a further aspect of the invention, a method for securing a jaw member having top and bottom mounting lugs to the frame of a jaw crusher comprises the steps of providing a pair of frame members, one of the frame members having a pair of tapered outer ends, positioning each jaw member mounting lug generally adjacent to a corresponding one of the frame members, positioning a threaded jaw rod having a pair of inwardly moveable wedge members between the one frame member and its adjacent mounting lug, and drawing the wedge members inwardly to so that a force is applied to the jaw member, thereby drawing the jaw member into firm contact with the frame.
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