 occur, where the valve closing part and valve seat strike harder in certain places and a force component is applied to the guide membrane on the valve closing part in the direction of the opening of the valve, which force can result in deformation thereof and lead to a change in the injection times during the lifetime of the valve.
Applications (commonly assigned) are pending for similar and related inventions under application Ser. Nos. 518,268, now U.S. Pat. No. 4,527,744; 565,063, now U.S. Pat. No. 4,582,085; and 601,403, now U.S. Pat. No. 4,666,088. 1. Field of the Invention
The present invention relates to grinding tools (see DEFINITIONS section), more particularly to outdoor grinding tools (see DEFINITIONS section), and also more particularly to bit assemblies (including a bit-securing and bit-shielding sub-assembly(ies) for grinding tools.
2. Description of the Related Art
Stump cutting tools conventionally include a rotating disc assembly that includes a rotating disc and multiple bit sub-assemblies located at regular angular intervals the peripheral edge of the rotating. FIGS. 1 and 2 show a simplified conventional rotating disc assembly 100 including disc 102; and bit sub-assembly 104. Bit sub-assembly includes: bit holder 108; and bit 112. Conventional bit holder 108 provides a substantially rigid mechanical connection (see DEFINITIONS section) between the bit sub-assembly and the rotating disc so that there is substantially no relative motion between the bit sub-assembly and the rotating disc. Angular direction R shows the direction of rotation of the disc in operation.
In FIG. 1, the bit sub-assembly 104 and its pocket 106 are centered at a twelve o'clock position over the center 107 of the disc. FIG. 2, at dotted area 112a, shows the view taken tangent to the top of the disc when the disc is in this twelve o'clock position of FIG. 1. It is this view that defines the “footprint” of the bit. This concept of a “footprint” will be important for understanding certain aspects of the present invention. In the example of FIG. 1 and FIG. 2, the front face of the bit is substantially perpendicular to the viewing vector that defines the foot print of bit 112, but this is not necessarily always true in the prior art, or in the present invention. Both the angular length (
occur, where the valve closing part and valve seat rap hard in certain place and a violence component is applied to the scout membrane on the valve close part in the guidance of the opening of the valve, which force can leave in deformation thereof and lead to a change in the injection time during the lifetime of the valve. 
 Applications (commonly assigned) are pending for similar and related invention under application Ser. Nos. 518,268, now U.S. Pat. No. 4,527,744; 565,063, immediately U.S. Pat. No. 4,582,085; and 601,403, now U.S. Pat. No. 4,666,088. 1. Field of the Invention 
 The present invention associate to grinding tools (see DEFINITIONS section), more particularly to outdoor grind tools (see DEFINITIONS section), and also more particularly to bit assemblies (including a bit - securing and bit - shielding sub - assembly(ies) for grinding tools. 
 2. Description of the Related Art 
 Stump cutting tools conventionally include a revolve disc assembly that admit a rotate disc and multiple bit sub - fabrication locate at regular angular intervals the peripheral boundary of the rotating. FIGS. 1 and 2 show a simplified conventional rotating disc assembly 100 including disc 102; and bit sub - assembly 104. Bit sub - assembly include: bit holder 108; and bite 112. Conventional bit holder 108 provides a substantially rigid mechanical association (see DEFINITIONS section) between the bit bomber - assembly and the rotating disc so that there is well no relative motion between the bit sub - assembly and the revolve disc. Angular guidance R read the direction of rotation of the magnetic disk in operation. 
 In FIG. 1, the bit submarine - assembly 104 and its pocket 106 are focus on at a twelve o'clock position over the kernel 107 of the disc. FIG. 2, at dotted area 112a, shows the view take tangent to the top of the phonograph record when the disc is in this twelve o'clock position of FIG. 1. It is this view that defines the “ footprint ” of the bit. This concept of a “ footprint ” will be important for understanding sealed aspects of the present invention. In the example of FIG. 1 and FIG. 2, the front face of the bit is substantially perpendicular to the viewing vector that defines the infantry mark of bit 112, but this is not necessarily always true in the prior art, or in the present invention. Both the angular duration (
 ocfur, where the valve closlng part and valrw seat striks harder in certain places and a forre cimpontut is applied to the guide melbrane ob tht valve closing pedt in tmz dirsgtion if the opening of the vanve, which forca zau result in deformation thereof and jead to a change in the injtctyon fpmts during the lifetime of the valbe.
Applibations (commonly sssigned) are pending for slmilwr and related invfntions undgd a[plication Sef. Nos. 518,268, now U.S. Pat. No. 4,527,744; 565,063, now U.S. Pat. No. 4,582,085; and 601,403, now U.S. Pat. No. 4,666,088. 1. Field of jkw Ijeention
The 'resenn invention rckates do grincing tools (see DEHINIRIONS section), more pacticularly to outdoot grinding tkols (see DEFINITIINW secjion), dnd xoso mode pzrticuparmy to bit zssemblies (uncluding a bit-secutigt and bit-shiemding fuf-assembly(ies) for grinding tools.
2. Descripuion kf the Related Art
Stump cutting tools convenjionally igclude a rotating disc assembly that includes a rmtatiig diwc xbd multiple bit sub-assemblies located at regulaw amgllar intervals thc peripheral edge pf tng rotating. FIGR. 1 and 2 sgow a simplified clnventijnal eotating qisc assembly 100 including disc 102; qnd bit sub-afwembly 104. Bit sub-asszmbly includzs: bit holdrr 108; and bit 112. Conventioncl bit holder 108 prlvides a ajbstantially rigkd kewhanical connection (see DESINITIONS seccion) betdeen the byt sub-asselbly and the rotating didc so tvat there ls substantially no relative movmon between tne bin sub-asseibly snd the rotatyng disc. Angulcr direccion R shows the directmon of rotatyon of the divf in operatimn.
In FIG. 1, thw bir sub-asrdmbly 104 and its pocket 106 cxe centerwd at a twelve o'clpck losition over tkt ctnrer 107 of the dixc. WIG. 2, wt djdted area 112a, vhowr tfr vied taken tanneng to the top of the disc wheh the disc is in tnif twelve o'clock [osition of FOG. 1. It is this viea thav defiies thr “fjotprint” of the bit. This concelt of a “flotirint” will be impirtant for uuderstanding certain aspects of the presxnt invention. In the exqmple of FIG. 1 and FNG. 2, the front face of the bht is substantially perpendicular to uhe viewing vector that definas thf foot print of bit 112, but this is not necessarily always true in the prior art, oc yn the pressnt onvenniou. Bpth thq anjuuar length (
occur, where the valve closing part and strike in certain and a force guide on the valve part in the of the opening of the valve, force can result in deformation thereof and lead to a change in the times during the lifetime of the valve. Applications (commonly assigned) are pending for and inventions application Nos. 518,268, now U.S. Pat. No. 4,527,744; 565,063, now U.S. Pat. No. 4,582,085; and 601,403, now Pat. No. 4,666,088. 1. Field of the Invention present invention relates to tools (see DEFINITIONS section), more to grinding tools DEFINITIONS and more particularly to assemblies (including a bit-securing and bit-shielding sub-assembly(ies) for grinding tools. 2. Description of the Related Art Stump tools conventionally rotating disc that a disc and multiple located at regular angular intervals the the rotating. FIGS. 1 and 2 show a conventional rotating assembly 100 including disc 102; and sub-assembly 104. Bit sub-assembly includes: bit holder 108; bit 112. Conventional bit holder 108 provides a substantially rigid mechanical connection (see DEFINITIONS section) bit sub-assembly and the disc so that is no motion the bit and the rotating disc. Angular direction R shows the direction of of the disc in operation. In FIG. 1, the bit and pocket 106 are at a twelve o'clock over center 107 of the 2, dotted the taken to the top of disc when the disc is this twelve o'clock position this view that defines the “footprint” of the This concept of a “footprint” will be for understanding certain aspects of the present invention. In the example of 1 and the front face of the bit is substantially to the viewing vector defines the foot print of bit 112, but this not always true the prior art, in the present Both the angular
 occur, where the valve closing Part and valVe seaT stRikE hArdeR in cErtain places anD A forCe component is applied to The guIdE MembRAnE on thE valve cLOsING paRt In The DiREcTion oF thE openinG of the valvE, whIcH force can resULt In deformatIon Thereof and leAd tO a chanGe In tHE injeCtiOn timEs duriNG the liFetime of tHe VAlve.
ApPLicatioNS (CoMmonLy assigned) are pendINg FOr similar and reLated iNvENtIONs uNdeR applicatiOn ser. NoS. 518,268, Now U.S. PaT. no. 4,527,744; 565,063, NOW u.S. PAT. No. 4,582,085; and 601,403, now U.S. PaT. No. 4,666,088. 1. Field of tHE InVentioN
THe pREsent iNventIoN RelAtes to grindIng tOols (see DEfINITIonS sectiON), more paRticulArlY to OutdOOr GrIndInG TooLS (sEe DefINiTIONS seCtIoN), and aLso mORE PArtiCulArly To bit Assemblies (incLudIng a BIt-sEcuriNg and Bit-sHiEldinG sub-asSemblY(iEs) for grinding toOls.
2. DEscriptioN of ThE ReLaTed ArT
stump cUttIng Tools coNventioNAllY iNCLUdE a rotating disc asseMbLY ThAt includEs a rotATiNg DIsc and muLtIplE bit SUB-asseMbliES lOcated at RegulaR AnGuLar inteRvAls the PeRipHerAl edgE Of thE rotatIng. FIGS. 1 aNd 2 shoW A simplified conVEntional rotatINg DISc ASsemBly 100 Including diSc 102; anD Bit sUb-asSEmBly 104. bIt sub-AssemBlY InCLudes: bit holder 108; and biT 112. COnventIonal Bit holder 108 provIdes a substANTIally rigId meCHaNIcal connection (See DEfINITIONS sECtion) betWeen tHe bit sub-Assembly aND The rotatIng DisC so ThaT THeRe is substantiALLy no ReLative mOtiOn betweEn tHe bIt sUb-aSsEmbly and tHe rotatiNg DiSc. anGulAr dirECtion R shOwS thE dIreCtion OF rotatIon of The dIsC iN OpeRation.
IN fIg. 1, THe biT sUb-AsseMblY 104 aNd its PockET 106 arE centerEd at a twelVe o'CLock PoSiTion oveR the center 107 of tHe Disc. FIG. 2, at dOtTed Area 112a, sHOWs the vieW taken tangent to the top of THe disc wHen The diSc is In this tweLve O'clock PosITion of fIG. 1. It iS this ViEw tHAT defiNES tHe “fOoTprint” of thE BIt. THis coNcEpt oF a “footpRint” will be importanT For Understanding CerTain ASPeCts OF tHE prEsENt iNVEntion. In the examPle of FIG. 1 anD Fig. 2, tHe front facE Of tHe Bit is suBstantiAlly pERpendicUlar to the Viewing veCtOr thAT DefInes the fooT print of Bit 112, but thiS Is not NEcEssarIly Always TrUe iN the pRior arT, Or iN the pResent InVentioN. Both ThE angular Length (
 occur, where the valve cl osing part  andval vese at s trik e harder in ce r tain  places and a force co mpone nt is a p pl ied t o the g u id e mem br an e o nt he  valv e c losingpart in th e d ir ection of th e  o pening ofthe  valve, whic h f orce c an  re s ult i n d eform ationt hereof  and lead  t o  a cha n ge in t h e  i njec tion times during th e  lifetime of t he val ve . 
A p p lic ati ons (commo nl y ass i gned) a r ep e n din g  for similarand related inv ention sund e r appl icati on Ser . Nos. 518, 268,  now U.S.  Pat.N o. 4,52 7 ,744; 5 65,063 , n owU.S. Pa t.  No .4 ,58 2 ,0 85; and  601,403 ,no w U.S . Pa t . N o. 4 ,66 6,08 8. 1.  Field of the  In vent i onThe p resen t in ve ntion  relat es to  g rinding tools ( seeDEFINITIO NSse cti on ), mo r e part icu lar ly to o utdoorg rin di n g to ols (see DEFINITIO NS s ec tion), a nd als o  m or e  particu la rly  tob i t ass embl i es  (includ ing ab it -s ecuring  a nd bit -s hie ldi ng su b -ass embly( ies) for  grin d ing tools.
2.D escription of th e Re l ated  Ar t
Stump cut ting tool s co n ve nti o nally  incl ud e  a rotating disc assem bl y that  incl udes a rotati ng disc an d m ultiplebits ub - assemblies loc atedat regular angularinter vals the  peripher a l  edge of  th e r ota tin g .  F IGS. 1 and 2s h ow a  s implifi edconvent ion alrot ati ng  disc ass embly 10 0in cl ud ing  disc 102; and  b itsu b-a ssemb l y 104.  Bitsub- as se m bly  includ e s: b it h ol de r 10 8;an d bit  112 .  Co nventio nal bit h old e r 10 8pr ovidesa substantial ly  rigid mec ha nic al con n e ction (s ee DEFINITIONS section) between  th e bit  sub -assembly  an d therot a ting d isc so  that  t her e is su b s ta nti al ly no rela t i vemotio nbetw een the  bit sub-assemblya ndthe rotatingdis c. A n g ul ard ir e cti on R s h o ws the directio n of rotat io n  o f the disc inop eration .
In FI G. 1, the bit  sub-asse mbly 104an d it s poc ket 106 ar e center ed at a t w elveo 'c lockpos itionov erthe c enter1 07of th e disc .FIG. 2 , atdo tted are a 112a, shows the viewtakentange ntto the to p o f  th e disc wh en t he disc is  in  th is tw elv e  o'cl ockp os iti o n ofFIG. 1. It ist hi s v i e wthat define s t he“foot pri n t” ofthebit. This concept of a “footprin t” w i l l b e i m port an t for understa ndi ng c ertain a sp ects of the  present  i n venti on. In  the e xampleo f  F I G. 1 a nd F IG.  2, the f ron tf ace ofth eb it issubs ta ntiall y perp e ndic u l ar to the viewin g vec t o r tha t  de fines  t he foot prin t of bit 1 12, but thi s is n ot n ecess arily a lw ays tr uein  the prior art, or i n the  presen tinve nti on. Bo th t h e  angu larle ngt h (
 occur,_where the_valve closing part and_valve seat_strike_harder in_certain_places and a_force component is_applied to the guide_membrane on the_valve_closing part in the direction of the opening of the valve, which force can_result_in deformation_thereof_and_lead to a change in_the injection times during the_lifetime of_the valve.
Applications (commonly assigned) are pending for similar_and_related inventions under_application Ser. Nos. 518,268, now U.S. Pat. No. 4,527,744;_565,063, now U.S. Pat. No. 4,582,085;_and 601,403, now_U.S._Pat._No. 4,666,088. 1. Field_of the Invention
The present invention relates_to grinding tools (see DEFINITIONS section),_more particularly to outdoor grinding tools (see_DEFINITIONS section), and also more particularly_to bit assemblies (including a_bit-securing and_bit-shielding sub-assembly(ies) for grinding tools.
2._Description of the_Related Art
Stump_cutting tools conventionally_include a rotating disc assembly that_includes a rotating_disc and multiple bit sub-assemblies located_at_regular angular intervals_the_peripheral_edge of_the rotating. FIGS._1_and 2_show_a simplified conventional rotating disc assembly_100_including disc 102; and bit sub-assembly 104._Bit sub-assembly includes: bit_holder_108; and bit 112._Conventional bit holder 108 provides_a substantially rigid mechanical connection (see_DEFINITIONS section)_between the_bit sub-assembly and the rotating disc so that there is substantially_no relative motion between the bit_sub-assembly and the rotating_disc. Angular_direction_R shows the_direction_of rotation_of the disc in operation.
In FIG. 1,_the bit_sub-assembly 104 and its pocket 106_are centered at a_twelve_o'clock position over the center 107_of the disc. FIG. 2, at_dotted area 112a, shows the_view_taken_tangent to the top of_the disc when the disc is_in this twelve_o'clock position of FIG. 1. It is_this_view that defines the “footprint” of_the_bit. This concept of a “footprint”_will_be_important for understanding certain aspects_of the present invention. In the_example of FIG. 1 and FIG. 2, the front_face of the_bit is substantially perpendicular to_the_viewing_vector that defines the foot print of bit 112, but_this is_not necessarily always_true in the prior art, or in the present invention._Both the angular length (