Abstract:
A splitting head for a log splitting apparatus includes abutting primary and secondary splitting assemblies, each having a circular securing ring that holds wedge members having cutting edges directed toward the log. The cutting edges of the secondary assembly split into smaller pieces the pieces produced by the primary assembly, producing a bundle of elongated pieces of firewood in parallel array and wherein the center of the bundle has not been compressed.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to apparatus for the splitting of wooden logs into small pieces useful as firewood. 
   2. Description of the Prior Art 
   Devices for converting logs into firewood generally employ a hydraulically driven ram-type mechanism which forces logs of pre-cut length into a stationary wedge having sharpened edges. As the log is axially advanced into the wedge, it splits into a plurality of sector-shaped pieces along cleavage lines that are generally directed radially with respect to the center axis and along medullar rays of the log. Typical examples of such devices are disclosed in U.S. Pat. Nos. 4,294,295; 4,353,401; 4,371,019; and 5,287,902. 
   In the production of firewood, there is considerable demand for “kindling” wood, namely pieces of firewood of small cross section which are easily ignited. The kindling wood, generally having a cross-sectional dimension less than about 3 inches, is further useful in small fireplaces or stoves or where there is no need for large, slow-burning logs to produce a substantial and prolonged thermal output. The kindling wood is also popular with elderly and disabled persons who cannot comfortably handle large firewood logs. For convenience and efficiency in marketing, the aforesaid kindling wood is generally sold in bundle form, secured by surrounding tying means such as string, wire, tape, or the like. 
   In order to produce split pieces of firewood of kindling size, a large number of pieces, generally between about 10 and 32 pieces, must be produced from logs commonly averaging 6″ to 20″ in diameter. Certain difficulties are encountered in seeking such  result. If all the splitting is sought to be accomplished in a single pass through one splitting head, the requisite ram pressure would be extremely high, thereby necessitating equipment of high cost, large size and limited portability. 
   In order to produce a large number of split pieces without excessively high ram pressure, the use of multiple splitting heads has been disclosed, as in U.S. Pat. Nos. 5,957,175 and 4,353,401, wherein a primary splitting head precedes a subsequent axially spaced downstream splitting head which splits the initially produced pieces into still smaller pieces. However, the design and intent of the aforesaid multiple splitting heads is to cause all pieces to have a sector shape, namely a 3-sided shape wherein one side represents the outer curvature of the original log, and the other two sides are substantially flat, straight surfaces that converge to a tip representing the center of the original log. Such sector shape, in small dimensions, causes difficulties in stacking wood in a fireplace. Also, the very thin tips are very splintery, producing frequent jamming in the splitting heads, and further cause some handling discomfort to the user. 
   Accordingly, a primary object of the present invention is to provide a splitting head for a log splitting, apparatus for producing kindling wood. 
   It is another object of this invention to provide a splitting head as in the foregoing object wherein said kindling wood is readily amenable to bundling. 
   It is a further object of the present invention to provide a splitting head of the aforesaid nature capable of splitting a log into many pieces with relatively little requisite ram pressure. 
   It is a still further object of this invention to provide a splitting head of the aforesaid nature capable of producing kindling wood of non-sector configuration. 
   It is an additional object of the present invention to provide a splitting head of the aforesaid nature which is of rugged and simple design amenable to low cost manufacture. 
   These objects and other objects and advantages will be apparent from the following description. 
   SUMMARY OF THE INVENTION 
   The above and other beneficial objects and advantages are accomplished in accordance with the present invention by a multi-wedge splitting head for a log splitting apparatus equipped with a ram and guide means for axially advancing pre-cut logs in a substantially horizontal direction, said splitting head comprising:
         a) a primary splitting assembly comprised of a first circular securing ring holding two diametrically extending wedge members intersecting at the center axis of said ring and having flat sides and forward cutting edges directed toward said ram, and   b) a secondary splitting assembly positioned behind said primary splitting assembly in axial alignment therewith and comprised of a second circular securing ring of larger diameter than said first securing ring and embracing two sets of orthogonally intersecting wedge members producing a square aperture centered on the center of said second ring, said wedge members having flat sides and a forwardly directed cutting edges formed by way of a single bevel surface facing said ring.       

   In a preferred embodiment of the invention, banding means may be disposed adjacent the exit extremity of said splitting head to consolidate the numerous pieces of wood into a bundle of sufficient integrity to permit transportation and storage. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawing forming a part of this specification and in which similar numerals of reference indicate corresponding parts in all the figures of the drawing. 
       FIG. 1  is a side and rear perspective view of an embodiment of the splitting head of this invention, shown in association with a a log splitting apparatus of conventional design. 
       FIG. 2  is a side view of the embodiment of  FIG. 1 . 
       FIG. 3  is a front view of the primary splitting assembly of the embodiment of  FIG. 1 . 
       FIG. 4  is a front view of the secondary splitting assembly of the embodiment of  FIG. 1 . 
       FIG. 5  is a sectional view taken in the direction of the arrows upon the line  5 — 5  of  FIG. 2 . 
       FIG. 6  is a sectional view taken in the direction of the arrows upon the line  6 — 6  of  FIG. 3 . 
       FIG. 7  is a sectional view taken in the direction of the arrows upon the line  7 — 7  of  FIG. 4 . 
       FIG. 8  is an enlarged fragmentary view of  FIG. 6 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring now to  FIGS. 1–7 , an embodiment of the log splitting head  10  of the present invention is shown installed into a splitting apparatus having an elongated structural base  11 , and a hydraulic ram  12  acting in the longitudinal direction of the base upon axis  16  and terminating in a pusher plate  13  which may be rotatable about the axis of the ram. Said ram is capable of exerting a force of between about 20 and 30 tons upon said logs. 
   Splitting head  10  is comprised of a primary splitting assembly  14  mounted in facing relationship with said pusher plate and in axial alignment therewith, and secondary splitting assembly  17  mounted rearwardly of assembly  14  and in contact therewith. Said assemblies are secured to base  11  by bottom, side and top structural members  18 ,  19  and  20 , respectively. A log  21  readied for splitting is placed upon base  11  and advanced by ram  12  toward splitting head  10 . Guiding track means  49  may be associated with base  11  to facilitate proper movement of the log. 
   Primary splitting assembly  14  is comprised of a first circular securing ring  22  bounded in part by leading and trailing circular edge surfaces,  31  and  32 , respectively, and embracing two diametrically extending wedge members  23  intersecting orthogonally at the center of said ring. Wedge members  23  have flat sides  24  and a forward cutting edge  25  having a cutting angle of between about 18 and 22 degrees. Said cutting edge is preferably formed in association with contiguous leading and trailing bilaterally tapered surfaces  44  and  45 , respectively, wherein the angle of convergence of said trailing surfaces is 8 to 12 degrees smaller than the angle of convergence of said leading surfaces. Such configuration of the wedge members at their cutting edges minimizes the force required by the ram to achieve splitting. Minimization of splitting force is a significant consideration in the apparatus of the present invention because of the large number of pieces produced in the splitting operation. 
   The thickness of wedges  23 , measured between opposing sides  24 , is preferably between about 0.50 and 0.75 inches as shown in  FIG. 8 . The width of wedges  23 , measured between cutting edge  25  and rear end  27  is preferably shorter than the width of ring  22 , and rear end  27  is coplanar with trailing circular edge surface  32 . Such recessed nature of the wedges within the first ring enables logs to be properly seated within the ring before being forced against cutting edges  25 . 
   Ring  22  may be further characterized as having interior and exterior surfaces  29  and  30 , respectively. The inside diameter of ring  22  may range between 16 and 24 inches, and its thickness, measured between said interior and exterior surfaces, is preferably about one inch. Ring  22  and its wedges are preferably fabricated of alloy steel hardened to Rockwell  40 – 50 . 
   Secondary splitting assembly  17  is comprised of a second circular securing ring  33  having a diameter between 12 and 15% larger than the corresponding diameter of ring  22 , and axially aligned therewith. Securing ring  33  embraces two sets of orthogonally intersecting wedge members  34  which produce a square aperture  35  centered upon the center of ring  33 . 
   Wedge members  34  are bounded in part by opposed flat sides  36 , and have a forwardly directed cutting edge  37  having an angle between 20 and 24 degrees and formed by way of a single bevel surface  38  facing outwardly toward ring  33 . Such cutting edge configuration reduces compression on central wood pieces i and D shown in  FIG. 5 . The thickness of wedge members  34  is between 0.50 and 0.75 inches, and ring  33  is of comparable thickness to ring  22 . Said wedge members and ring are preferably constructed of the same grade of hardened alloy steel as the corresponding components of the primary splitting assembly. 
   As shown in  FIG. 5 , the superimposed arrangement of the primary and secondary splitting assemblies causes a log to be split into 16 pieces, and none of such pieces have a sector cross-section. Said pieces emerge from the trailing, rear extremity of said secondary splitting assembly as parallel pieces in a loosly arranged bundle  40 . Banding means  41 , which may be string, rope, wire, tape or the like can then be applied manually or by separate mechanical means. A consolidated bundle is thereby produced wherein the separate pieces are easily removed and handled by virtue of their cross-sectional shapes and the fact that the central pieces have not been compressed. Additionally, the bundle may be employed in its entirety as a single log which will burn more quickly and with less smoke than the original log, the reason being that there is considerable air that is interactive with the interior region of the bundle. 
   While particular examples of the present invention have been shown and described, it is apparent that changes and modifications may be made therein without departing from the invention in its broadest aspects. The aim of the appended claims, therefore is to cover all such changes and modifications as fall within the true spirit and scope of the invention.