US2133212A - Hammer assembly - Google Patents

Description

' HAMMER ASSEMBLY Filed Jan. 24, 1938 c. F. SCHUTTE ET AL 2,133,212

Patented Oct. 11, 1938 UNITED STATES PATENT OFFICE HAMMER ASSEMBLY Charles F. Schutte and Herman D'. Schutte, Snyder, N. Y., assignors of one-fourth to Nellie D. Schutte, Snyder, N. Y.

Application January 24, 1938, Serial No. 186,719

4 Claims.

This invention relates to hammer assemblies for hammer mills of the type in which the hammers are detachably connected to the outer ends of swing arms pivoted to a driven rotary member,

each hammer being so constructed as to provide a plurality of impact faces so that when one impact face of a hammer becomes worn the hammer may be repositioned on its swing arm to present a new impact face. Such a type of hammer is disclosed in Patent No. 1,821,482 of Charles F. Schutte, dated September 1, 1931, upon which the hammer assembly of the present invention represents an improvement.

While hammers of the renewable face type have been successfully employed in hammer mills, difiiculty is encountered in providing simple and effective means for non-rotatably attaching the hammers to the swing arms so as to withstand the repeated shocks to which they are subjected and to permit their quick disengagement from the swing arms when it becomes necessary to change the impact faces of the hammers.

It is an important object of our invention to provide a quickly releasable connection for attaching the hammers to their swing arms which is composed of a minimum number of parts and so arranged as to be protected against flying lumps of material in the crushing chamber of the mill. An advantageous feature of the invention is the adaptability of the connecting means to different types of hammer assemblies in which either a single hammer or a plurality of hammers arranged in parallel is carried at the outer end of a swing arm or between a pair of Swing arms pivoted to the rotary member.

Another object of our invention is to provide connecting means for the hammers which project only a small distance beyond the lateral surfaces of the hammers or the swing arms so as to permit the swing arms to be assembled in closely spaced relation on the rotary member.

Other objects and advantages will be apparent from the following detailed description of several preferred embodiments of the invention, reference being had to the annexed drawing, in which:

Figure 1 is a side view of a hammer assembly of the type in which a pair of'hammers are mounted on the end of a swing arm;

Figure 2 is a longitudinal cross-sectional view of the hammer assembly of Fig. 1 viewed at right angles thereto;

Figure 3 illustrates the various parts of the hammer connection;

Figure 4 is a plan view of a difierent type of hammer assembly in which a single hammer is supported between a pair of swing arms; and

Figure 5 is a plan view of a hammer assembly similarto that of Fig. 4 but in which a series of hammers separated by spacing members are sup-- ported between the swing arms.

In the type of hammer assembly shown in Figs. 1 and 2 incorporating the invention, a pair of hammers l is carried upon the end of a swing arm 2 which latter is pivoted by means of a pin 3 to a driven rotary member 4. The hammers are each provided with four equidistantly spaced, radially extending legs la. providing a corresponding number of impact faces lb. In accordance with the usual mode of hammer mill operation, when the rotary member 4 is operated, centrifugal force throws the swing arm 2 outwardly and causes the hammers to impart blows with crushing force to: the material contained within the crushing chamber of the mill, not

shown.

In order to permit the repositioning of the hammers upon theswing arms so as to bring a new impact face of a hammer into operative position after one of the faces has become worn, it is usual to provide a detachable connection for nonrotatively retaining the hammers in assembly with their swing arm. According to the present invention there is provided a connection which may take the form of that best illustrated in Fig. 3 and comprising a pin 5 of square transverse cross-section and having an axial internally threaded bore 6 extending throughout its length, a pair of screws 1 having enlarged clamp ing heads la and collars 8 adapted to encircle the screws and provide countersunk seats 9 for the screw heads.

As best shown in the cross-sectional view of Fig. 2, the swing arm 2 and the pair of hammers I located upon opposite sides of the arm are provided with registering square shaped openings of a size just suflicient to pass the square pin 5. The pin is of a length so as to terminate approximately flush with the flat outer faces of the hammers. The collars are slipped over the shanks of the screws and the screws then threaded into the bore of the pin, as by means of a screw driver engaging kerfs 10 in the heads of the screws, until their heads tightlyengage the bottoms of the seats 9. This causes the collars 8 to be drawn into clamping engagement with the hammers and prevents endwise displacement of the pins in their openings.

When so assembled with the swing arm the hammers are positively restrained against rotation by means of the square pin engaging complementary openings in the hammers and swing arm. At the same time it is only necessary when one impact face of a hammer becomes worn to remove the screw 7 which holds the hammer in association with the swing arm, together with its collar 8, slip the hammer from the end of pin 5,

turn the hammer through 45 degrees to bring a new impact face to operative position and then reclamp the hammer on the swing arm in its new position. Likewise the hammers may be entirely reversed in position as occasion demands so as to make available four additional edges of their impact faces, each hammer thereby furnishing eight grinding positions upon their four impact faces.

In Fig. 4 is shown another form that the invention may assume. In the hammer assembly of this figure a single hammer 20 of the multiple face type is located between and at the outer ends of a pair of companion swing arms 2|. The hammer is non-rotatably and detachably secured to the swing arms by a connection corresponding to that disclosed in Fig. 3. This assembly differs in no essential respect from that previously described except that a square pin 22, corresponding to pin of the assembly of Figs. 1 and 2, extends through aligned openings in the two swing arms and hammer. The pin is retained in association with the swing arms by screws 23 encircled by collars 24, corresponding to the screws 1 and collars 8 of the aforementioned figures. The screws are threaded into opposite ends of a central bore 25 in the pin and their enlarged heads seat within counter-sinks in the collars, as indicated in dotted lines, so as to retain the pin against endwise movement.

Another embodiment of the invention is shown in Fig. 5 which discloses a hammer assembly which partakes of the nature of both of the hammer assemblies previously described. This assembly comprises a pair of swing arms 30 (although any suitable number of swing arms may be provided at spaced intervals) between which arms are assembled a series of hammers 3| of the multiple face type. A square pin 32 passes through corresponding openings in the swing arms and hammers and its ends project a sufficient distance beyond the outwardly disposed sides of the pair of swing arms to allow additional hammers 3Ia to be fitted thereover. Headed screws 33 encircled by collars 34 (corresponding to the screws 1 and collars 8 of the embodiment of Figs. 1 and 2) are axially threaded into a central bore in the pin and clamp the collars against the sides of the hammers 3la. For uniformly spacing apart the series of hammers located between the pair of swing arms, spacer rings 35 centrally provided with square openings passing the pin 32 are positioned between adjacent hammers.

It will be apparent from the embodiments of the invention described above that the hammers are positively locked against rotation upon the ends of the swing arms and that in every instance the square pins are enclosed throughout their length and protected from flying debris within the mill. This prevents the pins from damage and avoids chipping and distortion of the corners of the square pin which would interfere with the ready removal of the pins from the hammers when changing their impact faces.

The transverse cross-sectional shape of the pin need not necessarily be square but may be of other non-circular shapes. This would be particularly true in the case of hammers having a different number of impact faces from the four faces disclosed in the hammers of the above embodiments. However, in the case of square or rectangular pins, the four right-angled corners have been found to afford maximum resistance against turning of the hammers thereon as well as to permit their ready assembly with the hammers.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics of the invention, and the present embodiments are therefore to be considered as illustrative and not restrictive, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

We claim:

1. A hammer assembly of the class described comprising a swing arm and means for nonrotatably and detachably connecting a hammer having a plurality of impact faces to the outer end of the swing arm, said connecting means comprising a pin of angular transverse cross-section extending through registering openings corresponding to the cross-section of the pin in the swing arm and hammer, means for preventing endwise displacement of the pin in one direction and means for preventing endwise displacement of the pin in the opposite direction, said lastmentioned means comprising a screw axially threaded into the pin and having an enlarged clamping head and a collar surrounding said head and providing a countersunk seat for receiving the clamping head of said screw.

2. A hammer assembly of the class described comprising a swing arm and means for nonrotatably and detachably connecting a hammer having a plurality of impact faces to the outer end of the swing arm, said connecting means comprising a pin of square transverse cross-section extending through registering openings corresponding to the cross-section of the pin in the swing arm and hammer and means preventing endwise displacement of the pin, said last-mentioned means comprising screws axially threaded into opposite ends of the pins and having enlarged clamping heads and collars surrounding the screws and providing countersunk seats for receiving the clamping heads of said screws, whereby the pin is protected substantially throughout its entire surface against damage.

3. A hammer assembly of the class described comprising a plurality of swing arms arranged in parallel and means for non-rotatably and detachably connecting a series of hammers each having a plurality of impact faces to the outer ends of said swing arms, said connecting means comprising a pin of angular transverse crosssection extending through registering openings corresponding to the cross-section of the pin in the swing arms and hammers, spacer members surrounding the pin and disposed between adjacent hammers and means preventing endwise displacement of the pin, said last-mentioned means comprising screws axially threaded into opposite ends of the pins and having enlarged clamping heads and collars surrounding the screws and providing countersunk seats for receiving the clamping heads of said screws, whereby the pin is protected substantially throughout its entire surface against damage.

4. A hammer assembly of the class described comprising a swing arm and means for nonrotatably and detachably connecting a hammer having a plurality of impact faces to the outer end of the swing arm, said connecting means comprising a pin of angular transverse cross-section extending through registering openings corresponding to the cross-section of the pin in the swing arm and hammer, means for preventing endwise displacement of the pin in one direction and means for preventing endwise displacement of the pin in the opposite direction, said last-mentioned means comprising a screw axially threaded into the pin and having an enlarged clamping head and a collar surrounding said head and providing a countersunk seat for receiving the clamping head of said screw, said collar being of greater diameterthan the maximum transverse dimension of the pin so as to completely cover an end of the pin.

CHARLES F. SCHUTTE.

HERMAN D. SCHUTTE.

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