US2264915A - Jaw crusher - Google Patents

Description

Dec. 2, 1941. K. MEISTER 2,264,915

JAW CRUSHER Filedv April 28, 1939 Fig. 2

lnvenfor Karl Meister Attorney Patented Dec. 2, 1941 i Karl Meister, Magdeburg, lGermany, ass'lgnorfto Fried. Krupp, Grusonwerk, Aktiengesellschaft,` -Magdeburg-Buckau, Germany Application April 28, 1939, Serial No. 270,555

In Germany April 29, 1938 1 Claim. (CL 83-53) My invention relates to improvements in high duty jaw breakers or crushers working on the concussion principle, namely having an oblique- I ly disposed breaking gapformed by a steeply inclined stationary jaw and a less steeply inclined swing jaw, which is arranged beneath the former and is reciprocated by an eccentric at an unusually high working speed ranging between about 350 and 400 revolutions per minute, and through an abnormally large distance or stroke, exceeding by two and more times the net clearance between the lower ends of the jawshereinafter called width of the discharge gap.

The improvements aimed at by this invention will be more readily understood by synoptically reviewing at rst the principal structural and working characteristics of jaw crushers of the concussion type as known for instance from United States Patents 1,987,761 to Symons and 2,123,017 to Meister, andr those ordinary jaw crushers having a substantially vertically disposed breaking gap and being generally known as Blake crushers.

With Blake crushers having a vertically disposed breaking gap and running generally at a working speed of only from 200 to 220 revolutions per minute the swing jaw moves relatively slowly-and makes relatively short strokes ranging below the width of the discharge gap; the material under treatment gravitationally forces its way relatively slowly through the breaking gap and is directly crushed by compression, namely by, receiving slow actingfcrunchesk in contradistinction thereto-With crushers of the concussion type set forth-the material is what may f be called dynamically crushed between the rapidly moving swing jaw and the stationary jaw and is both dynamically and gravitationally accelerated on passing through the breaking gap with the resultthat a larger output per hour is obtained; in other words the swing jaw drops so quickly from under the material after every crushing impact that the material is free to drop vertically away from the stationary jaw until hitting and being crushed by the returning swing jaw.

As the result of practical experiments on which the disclosure in the inventors prior United States Patent 2,123,017 is based, it has been found desirable to provide crushers of the concussion type concerned with a swing jaw having a coni Vex working face one-dimensionally curved in the middle and terminating in a practically flatupper end extending at a small angle to the horizontal.

at first and is spontaneously retained somewhat on the flat and only slightly inclined upper end of the swing jaw and gradually slides down thereon at an increasing speed consistent with the progressive crushing and in proportion to the progressive inclination of the working face of the swing jaw, with the result that a considerable proportion of the crushing work is done in the upper part of the crusher, and that the quantity of the material passing therethrough at increasing speed is practically uniform in the upper and lower crushing zones (page 1, right column, lines seff).

The material charged into the crusher' rests 55 In this way overstressing of the crusher in the lower crushing zones and choking of the latter is avoided (page 1, left column, lines 27-29).

However in the course of further practical experiments it has been found, that jaw crushers of the concussion type having a swing jaw of the speciiic shape and disposition shown in the United States Patent 2,123,017, although ensuring -a steady and uniform ow of the material through the crusher, show certain drawbacks hereinafter described on deviating from a certain medium or normal size of the crushed products by enlarging or reducing the width of the discharge gap:

Namely it was found, that on widening the discharge gap from its normal width to a larger and eventually to its maximum width by angularly re-setting one of the jaws, the output of the crusher continues to be--contrary to expectationspractically the same as in crushing the material to normal size, but is not larger in proportion to the wider discharge gap.

On the other hand reducing the width of the discharge gap of the crusher concerned resulted in an increased production of undesirable nes, in choking of the lower crushing zones, increased power consumption and overstressing of vital parts of 'the crusher.

The principal object of this invention is to overcome the said drawback in a more simple and less time-consuming manner; more especially 'the invention aims at so re-designing jaw crushers of the concussion type concerned, that the size of the crushed products can be changed within wide limits, namey so that on widening the discharge gapl for producing a larger size product f the output of the crusher grows correspondingly larger, while on narrowing the discharge gap the output is reduced and choking or overstressing of the crusher and its driving elements is avoided.

Other objects aimed at by the invention will 2v A Y 2,264,915

be more fully understood from the following speci- 5 ilcation taken together with the accompanying drawing, in which Fig. 1 is a section vertically taken through a crusher re-designed according to this linvention;

Fig. 2A is a section vertically taken through a 10 structurally modiiied crusher.

In both figures the principal component parts only of the re-designed crusher are shown diagrammatically and by way of examples.

Briefly stated the invention consists in providing vboth jaws of the crusher with what may be called differential adjusting means explained more in detail hereinafter and enabling the operator to tilt more or less the breaking gap of the crusher-as against angularly re-setting a single jaw only--in accordance to changes made in the width of the discharge gap.

I The research work undertaken by the inventor in connection with crushers of the concussion type described in `his .United States Patent 2,123,017 .has revealed', that on re-adjusting the swing jaw alone from its normal position, wherein standard size products are made into its fully open position for. the production of larger sized products, its overall angle of inclination diners so very little-only by 1.to 11/2 degrees-from its former angle to the horizontal, that the 'material gravitationally sliding down on the convex working face of the swing jaw is accelerated at rpractically the same rate as before; in other` words the slightly increased inclination f the swing jaw is insuiiicient to advance the material adequately and consistently with the desired larger output of the crusher.

Likewise, when the width of the discharge gap 40 is reduced the angle of inclination of the re-set swing jaw diiers so little from its former angleless than one degree-that practically the same Vquantity of material slides down into the narrower lower crushing zones as before when a ustandard size product was made, with the result, that in addition to increased power consumption choking of the lower crushing zones, overstressing of the driving elements of the crusher and other troubles ioccur.

The jaw crusher re-designed with the objects inv view stated above and shown in Fig. 1 compr1ses:

' f (1i A machine-frame 3 provided with a hop- 55 per 4,

(2) A stationary upper jaw 5 having an inclined lower crushing face 6, which is slightly inwardly curved at its upper end,

(3) A lower swing jaw 1 hinged to the ma-I ehineframe at I0 and forming with the upper 60 jaw an obliquely disposed breaking gap; 'the swing jaw I has a conv'ex crushing face 8 opposed to that of the upper jaw and having an in.-l

creasing inclination towards the discharge gap I;

arm I3. integral therewith and a. thrust or nose plate' I4 interengaging said arm I3 and the swing JaW (5) With the objects in view, stated above and more especially of substantially promoting the ow of the material through the crusher, namely balancing the supply of material with the desired greater output of the crusher on Widening the discharge-gap, means are provided according to this invention for re-adjusting angularly both jaws and incidentally tilting the breaking gap through a progressively steeper angle; said readjusting means comprise y (a) A horizontally disposed hinge, bolt or pivot I5, by which the upper end of the stationary jaw 5 is hinged to the machine frame 3, a set screw I6 threaded in the machine frame 3 and engaging jaw 5, and'another set screw I1 hinged to the upper jaw 5 for retaining it in its re-adjusted steeper or lless steeply inclined workingposition, (b) Re-setting means for changing the active length of said nose plate'l4 so as to rangularly displace the swing j'aw 1, which comprise slots 2U provided in said'arm I3, screw bolts 2 I extending therethrough for adjustably clamping the said nose plate I4 to said arm I3 of the eccentric I2 and a distance piece 22, chosen from a few distance pieces of different width kept in stock and inserted between said nose plate I4 and eccentric I2.

Instead of an eccentric, shown by way of an example, other appropriate means known and Y used in this art including cam gears, wedge, lever and toggle motions may be convenientlyused for reciprocating the swing jaw 1.

The stationary jaw 5 Vmay be provided to advantage with adjusting means in the form of eccentric cams engaging the stepped lower section of said jaw from within 'and being 'cooperatively associated with a safety device in thelform of powerful springs supporting the lower endJof the jaw from without as shown in United States Patent 2,049,819.

Various other changes and modifications may be conveniently made in the strictural details of jaw crushers of the improved design described, without departing from the spirit and the salient ideas of this invention:

In the crusher shown by way'of another vexample in Fig. 2 structurally modied means are shown for tilting the breaking gap by diierentially readjusting both jaws relatively to each other for the purposes of thisinv'ention, which comprise ((a) A horizontally disposed bolt or pivot I5. by which the upper end of the stationary jaw 5' is hinged to the machine frame 3', a setvscrew I6' threaded in the machine frame and engaging jaw 5' from without, and another set screw I1 hinged tothe lower end of jaw 5 for retaining it in its re-adjusted steeper or less steeply inclined working position;

(b) fA base member 23 having a horizontally disposed pivot 24, on which the front end of the machine frame 3' is fulcrumed'so as to be capable of being tilted through a considerable angle preferably exceeding ve degrees and indicated by arrow x, distance plates 25, 26 assembled one above the other and exchangeably nested within each other for supporting the machineframe 3' at its rear end, and clamping screws 21 hinge to the base member 23 for retaining the machin frame in its tilted position.

l, By practical comparative tests in the cours of which the breaking gap is tilted through diier ent angles of inclination, while the width of the discharge gap is step by step changed from its minimum to its maximum, the most favorable angles of inclination should be determined and the jaws differentially adjusted accordingly in order to obtain a maximum output of the crusher, when making a crushed product of a predetermined size.

As stated above there are jaw crushers working according to the old compression principle and being Widely known in the art as Blake crushers, which are distinguished from the concussion type crushers in that the working stroke of their swing jaw is only about half of that of concussion crushers, and that they can be operated to advantage only at a maximum working speed not exceeding 200 to 220 cycles per minute as against 350 to 400 cycles with concussion crushers.

I am aware, that it is common practice to provide the swing jaw of Blake crushers or their stationary jaw with re-setting means for changing the width of the breaking gap and the size of the crushed product, and that there are exceptional cases, in which even both jaws are capable oi being reset for specific purposes, as seen in United States Patent 1,899,930. I explicitly disclaim as my invention the application of such resetting means for the jaws of Blake Crushers in general; my invention as claimed hereinafter is directed to overcoming an aforedescribed drawback, not existing in Blake crushers but being specific of and curtailing the usefulness of Crushers of the concussion type, disclosed in my prior United States Patent 2,123,017, which have an inclined breaking gap and a swing'jaw formed at its 'lower section with a convex curved crushing face having a progressively increasing inclination towards the discharge gap, and which work at an unusually high speed, ranging from about 350 to 450 cycles per minute, and with an unusually long stroke.

`What I claim is:

In a jaw crusher of the concussion type set forth, a stationary first jaw extending substantially diagonally to the vertical, pivotally,mount ed adjacent its upper end for adjustment on a xed pivotal point, means to adjust the lower end of said stationary jaw upwardly and downwardly about its xed pivotal point, an actuated second jaw pivotally mounted adjacent its upper end and positioned to move on a fixed pivotal point spaced, from said pivotal point of said rst jaw in operative crushing relation beneath said first jaw, and presenting toward the latter a convex crushing face and a progressively sharper downward inclination toward its lower end, means to adjust the lower and upper limits of the lower end of said second jaw, means adapted to apply force to the lower end of said second jaw to move said second jaw up and down about its pivot to effect a crushing action upon material between both said jaws, a frame member supporting both said upper and lower jaws, a pivoted mounting on an axis parallel to the pivot of the second jaw about which said frame and the jaws carried thereby may be tilted as a whole in a plane parallel to the plane of pivotal movement of said second jaw, and adjusting means for securing said frame in any predetermined position.4

KARL MEISTER.

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