as stated above , the present invention provides a multiple - pivot apparatus that can lift , excavate , secure , split and / or crush tree stumps , as well as other materials , particularly other wooden materials . referring now to fig1 and 5 , a tree stump lifting and crushing apparatus 10 of the present invention is shown . the apparatus generally comprises three main components , an arm - like supporting structure 11 , an engaging unit 12 , and a cutting device 13 . in a preferred embodiment , these components are made of mild and high carbon steel , e . g ., t 1 , or other suitable metal material . such materials are commercially available from a variety of steel suppliers . the supporting structure 11 has a curved l - shape and is movably attached at its upper end 11 ′ to a suitable power source , e . g ., a hydraulically powered , manipulatable boom such as a bucket arm of a digging machine 27 ( as shown in fig5 ). as shown in fig4 a - 4 b , the supporting structure 11 comprises two reinforcing side plates or sticks 15 and 15 ′, with a stick backplate 16 disposed therebetween . in a preferred embodiment of the present invention , sticks 15 and 15 ′ have a wider diameter at their lower end , to which a similarly shaped reinforcing plate , referred to as supporting plate 17 and 17 ′ is welded or otherwise mountably attached . this design provides additional reinforcement to the supporting structure during the cutting process and avoids destructive engagement of the engaging and cutting device . in a particularly preferred embodiment of the present invention , the lower surfaces of supporting plates 17 and 17 ′ are serated as denoted by reference numeral 30 in fig4 b and 7 . the serated edges absorb force and further reduce the opportunity for slippage of the tree stump or other work material during the crushing and excavating operation . the thickness of the sticks 15 and 15 ′ is preferably about 1 to ½ inches , more preferably about ½ to 1 inch , most preferably about 3 inch . the thickness of the supporting structure backplate 16 is preferably about ¼ to ½ inches , more preferably about ½ to 1 inch , most preferably about ¾ inch . as shown in fig1 and 7 , the engaging unit 12 and cutting device 13 are each pivotably and opposedly connected to the lower portion 11 ′ of the supporting structure 11 by means of two pivot pin assemblies 14 and 14 ′, respectively . referring to fig7 the pivot pin assemblies are shown in partially assembled detail . the multiple pivots of an apparatus of the invention may be suitably spaced apart by a relatively wide range of dimensions . preferred distances to space the multiple pivots may depend in part on the targeted use of the particular apparatus . more specifically , referring to fig1 pivots 14 and 14 ′ may be suitably spaced ( i . e . distance x in fig1 ) from about 10 inches to 6 feet , more typically distance x being from about 1 foot to about 4 feet . a distance x between pivots 14 and 14 ′ of about 3 feet may be particularly preferred . it also is generally preferable that the length of the engaging unit and cutting or grappling devices be essentially unilateral with respect to the distance between the pivots . again , referring to fig1 respective distances y and z are preferably substantially equivalent to distance x . in preferred embodiments of the present invention , the configuration of distances x , y and z provide an opening at maximum power of about 6 to about 15 feet , more preferably of about 7 to about 12 feet . referring to fig2 and 7 , the engaging unit 12 comprises two side plates 18 and 18 ′, with each side plate having a spear - like extension , 19 and 19 ′ respectively , extending from its leading edge , and a backplate 20 securely disposed therebetween . in a preferred embodiment , extensions 19 and 19 ′ comprise replaceable teeth with a cap pinned to a shank unit which are welded to side plates 18 and 18 ′. the backplate 20 provides significant support and reinforcement to the engaging unit 12 during the lifting , excavating , splitting and crushing process . the planar design of the backplate 20 does not invite any clogging or debris from the stumps being crushed . therefore , opportunity for damage to the apparatus associated with clogging or debris and the downtime associated therewith are substantially eliminated . the thickness of side plates 18 and 18 ′ of the engaging unit 12 is preferably about 1 to 2 inches , more preferably about 1½ inches . the thickness of the engaging unit &# 39 ; s backplate 20 is preferably about 1 to 2 inches , more preferably about 1½ inches . referring with particularity to fig2 d , an alternate preferred embodiment of the engaging unit is shown to include a rake attachment 29 . using such a configuration , the engaging unit can perform an additional function without disrupting the excavating and cutting operation . for example , the rake attachment 29 can be used as a tool for clearing debris , dirt and the like from the work area during the operation . such an attachment is typically welded to the engaging unit &# 39 ; s back plate 20 or to a tool bar in proximity thereto . a variety of other attachments also may suitably be used to facilitate various functions , e . g ., a blade attachment for specialized excavation . referring to fig3 the cutting device generally comprises a curved , sharpened outer surface , termed a knife blade 21 . in a preferred embodiment , a similarly curved , elongated knife tooth 22 is mountably attached to the knife blade . the knife tooth provides a penetration point for initiating the splitting process . preferably , the two sides of the knife tooth 22 and 22 ′ extend across about the lower ⅔ section of the knife blade 21 . the knife tooth is preferably made from ar 400 steel ( an abrasive resistant form of t - 1 ). a knife tooth plate 23 is disposed between the two sides of the knife tooth and provides reinforcement and strength to the cutting device structure during the tree stump splitting and crushing process . the knife tooth plate 23 also increases the wear - resistance and longevity of the device . the knife tooth and knife tooth plate may be removed , sharpened and replaced as necessary . in an alternate embodiment of the present invention , the apparatus 10 comprises a grappling unit 28 . referring to fig6 grappling units 28 and 28 ′ extend from either side of pin assembly 14 ′ and connect to the respective sides of knife tooth 22 and 22 ′. the grappling unit may be used in addition to the cutting device components described above , or it may be manufactured as a stand - alone unit . as should be understood from fig6 with grappling unit 28 , apparatus 10 can be employed to haul or otherwise transport any of a variety of materials , including tree stumps or other loads that may be present at an excavation site . additionally , by employing the multiple spaced pivots for engaging and grappling units , greater volumes of materials can be lifted and transported with an apparatus of the invention , relative to prior grappling systems . as in the case of the knife tooth , the other components of the cutting device are preferably made from ar 400 steel ( an abrasive resistant form of t - 1 ). the thickness of the sides of the knife tooth 22 and 22 ′ and the knife tooth plate 23 are preferably ¼ to 1 inch , more preferably about 2½ inch . the thickness of the knife blade 21 is preferably about 2 to 4 inches , more preferably about 2½ inches . referring to fig1 a and 5 , a plurality of anchor hooks 24 protrude from each of the outer surfaces of sticks 15 and 15 ′ in one preferred embodiment of the present invention . the anchor hooks 24 , preferably welded to the sticks 15 and 15 ′, provide a means of securing a first and second reinforcing member 25 and 25 ′ ( shown in fig5 ) on either side of the sticks 15 and 15 ′. typically , one end of the reinforcing member 25 is mounted to one or more of the anchor hooks 24 ; the other end is secured to , e . g ., connected and / or in communication with , the pivot point assemblies 14 and 14 ′. this novel aspect of the present invention provides additional support and durability to the apparatus during the tree lifting and crushing operation . further , this design provides significant ease of operation in terms of mounting and dismounting attachments relative to an excavator . in an alternate preferred embodiment of the present invention , the first and second reinforcing members 25 and 25 ′ are secured to the supporting structure by a plurality of clamps 31 and case hardened steel pins 32 ( shown in fig7 ). such a configuration eliminates the need for welding anchor hooks or a similar structure on the sticks of the apparatus , thus eliminating the possibility of damage to the boom , e . g ., cracks and the like , which may result as a consequence of welding . referring with particularity to fig5 movement and communication of the engaging unit 12 and cutting device 13 are facilitated by auxiliary hydraulic circuits , designated herein as hydraulic cylinders 26 and 26 ′. on one side of the supporting structure , a first hydraulic cylinder 26 is attached at one end to an aperture 28 on reinforcing member 25 . referring also to fig7 the other end of the hydraulic cylinder is attached to a rear portion 33 of engaging unit 12 . on the other side of the supporting structure , a second hydraulic cylinder 26 ′ connects reinforcing member 25 ′ to a rear portion , e . g ., aperture 34 , of cutting device 13 . in a preferred embodiment , case hardened steel pins 32 are used to facilitate these attachments . the two hydraulic cylinders 26 and 26 ′ can be manually retracted and extended using hydraulics controlled from the cab of the digging machine . this operation facilitates movement and communication of the engaging unit 12 and cutting device 13 during the tree stump lifting and crushing process . further , the novel configuration of the present invention provides a crushing device which offers maximum power ( force ) when the engaging unit and cutting or grappling devices are in an open position , e . g ., positioned at a 90 ° angle with respect to the arm - like supporting structure . referring again to fig5 the tree stump lifting and crushing operation can be illustrated as follows . using hydraulics controlled from the cab of the digging machine , the operator of the digging machine can move the bucket arm of the digging machine 27 to deploy the arm - like supporting structure 11 to the desired location in proximity of the targeted tree stump . the engaging unit 12 and cutting device 13 are then drawn back and apart utilizing their respective hydraulic cylinders 26 and 26 ′ and pivot point assemblies 14 and 14 ′. the tree stump then can be grasped , lifted and positioned securely against engaging unit 12 . while the stump is securely held by engaging unit 12 , splitting and crushing of the stump is effected by retracting and releasing the cutting device 13 utilizing hydraulic cylinder 26 ′ and the hydraulic controls associated therewith . depending upon the length and size of the stump , this movement can be repeated as necessary to effect the desired degree of crushing of the stump . the terms and expressions which have been employed herein are used as terms of description and not of limitation . there is no intent , in the use of such terms and expressions , of excluding any of the equivalents of the features shown and described or portions thereof , but it is recognized that various modifications are possible within the scope of the invention claimed .
the present invention provides an apparatus that lifts , secures , splits and / or crushes tree stumps or other materials , particularly wooden materials and other materials that may be present at an excavation site . the apparatus is characterized in part by a two pivot point design . a first pivot point allows for the pivotable operation of an engaging unit which grabs and lifts the tree stump . the engaging unit further acts a durable and secure support member for the tree stump during the splitting and crushing process . the second pivot point allows for the pivotable operation of a cutting device which facilitates splitting and crushing of the stumps .