US 2638944 A
Description (OCR text may contain errors)
May 19, 1953 A. woLEsLAGLE CHAIN SAW GUARD Filed Feb. 7, 1951 Nw Nm. es.. M
. wu ma@ mw V m@ M 33 C21/MLA '4' l 'l f 'l oTnCy May 19, 1953 A. w'oLEsLAGLE CHAIN SAW GUARD 3 Sheets-Sheet 2 Filed Feb. 7, 1951 INVENTOR.
May 19 1953 A. woLEsLAGLl-z v2,638,944
CHAIN sAw GUARD Filed Feb. 7, 1951 3 Sheets-Sheet 3 L\ KM 5S w Patented May 19, 1953 UNITED STATES PATENT OFFICE Arnold Woleslagle, Geneseo, N. Y.
Application February '7, 1951, Serial No. 269,716
1o Claims. (o1. 14s- 32) This invention relates to a guard for power driven saws of the kind commonly7 known as chain saws.
An object of the invention is the' provision of 'a generally improved and more satisiactory guard for saws of this kind.
Another object is the provision or" a practicable chain saw guard sufc'iently light and compact so as not to interfere substantiallj,7 with lthe proper use of the saw, while at the same time giving adequate protection against injury to the operator.
Still another object is the provision of a chain saw guard so designed and constructed as to be practical for use when the saw is taken aloft, lup a tree or pole. v f
A further object is the provision of a chain saw guard so designed 'and constructed 'that itrnay Ibe applied. to certain types of existing chain saws, as well as to rthose hereafter built, and may be lreadily removed from the saw when desired.'
These and other desirable objectsv may be attained in the manner disclosed. as an illustrative embodiment of the invention in the following description and in the accompanying' drawings forming a part hereof, Ain which: Y
Fig. 1 is a view partly in side velevation and partly in `vertical section taken longitudinally through a saw guard in accordance with a preferred embodiment of the present invention, as applied Ito a chain saw of conventional construction, the guard being fully exten-ded to its normal position lprotecting the full length of the saw;
Fig. 2 is aside elevation of the guard removed from the saw; f
Fig. 3 is aside view somewhat similar to Figs. 1 and 2, butV with the saw being used to saw through a piece of wood, and with the guard partially collapsed to permit such sawing;
Fig. l is a top plan View of the saw guard removed from the saw and in fully extended position;
Fig. 5 is a. longitudinal section taken centrally through the joint between two of the sections of a guiding or supporting tube ofthe saw guard;
Fig. 6 `is a fragmentary section taken longitudinally through the upper part of the saw guard showing the upper guiding or supporting tube and the upper part of the casing or guard members in collapsed position; 1
' Fig. '7 is a front face view of the bucking bar at the forward end of the guard;
Fig. 8 is a transverse section taken approximately on the line 8 8 of Fig. 2; and
Fig. 9 is a transverse section taken approximately on the line 9--9 of Fig. l.
The same reference numeralsv throughout the several views indicate the saine parts. y
Chain saws are well known, and are made by a number vof 4different manufacturers, in various sizes and forms, some being driven by internal combustion engines and some .being driven by electricrmotors. In the specific embodiment here shown as an example, the saw guard of the present invention is applied to one known form of chain saw, but it will be understood that by varying the details of the parts-of the present saw guard. which directly contact with the stationary frame parts of the sat/'fthe saw guard of the present invention may be adapted to various other kinds, styles and sizes of saws.
Referring first to Fig. l of the drawingsotnere is shown somewhat diagrammatically certain parts of a known commercial form of chain saw including a housing 2l containing the driving motor, a rear hand grip or handle 23, and a bracket 25 to which is secured a cross bar 2 forming an up-perhandle for supporting the machine. The motor within the casing 2| drives Aa sprocket 29 over which runs a chain 3| having saw teeth formed thereon in known manner, the 'chain running over a fixed plate-like guide the forward end of which is shaped approximately as a semicircle, as shown.
All of this is well known, and the details thereof may take various forms, as above indicated. To this conventional structure, the guard of the present invention is added. This guard includes abucking bar for contact with the work to be cut, suitable guides or supports for guidingthe bucking bar in its retracting and advancing movements, -and a guard casing associated with the bucking barA and guides for guarding the saw chain against accidental lateral contact with other objects.
' In the preferred form, the guides comprise a pair of telescoping tubes indicated infgeneral at 4| and v43 respectively extending longitudinally above the top and below the bottom of the saw chain 3|. substantially identical construction and a description of one will suffice for both. Each tube comprises a xed base section i5 rigidly but detachably fastened to the motor casing 2| or other lined part of the saw mechanism, and a pluralityy The top and'bottom tubes maybe of 3 for contact with the log, limb, or other article to be cut, and which has a slot 55 of sucient dimensions so that, when the guides 4| and 43 are telescopically collapsed, the bucking bar 53 may move rearwardly (to the left when viewed as in Fig. 1) in a direction axially of the saw, with the saw chain projecting forwardly through the slot 55.
Each ofthe telesoping guides 4| and 43 may have anyfdesire'dliuberof sections.' "Merely as an example, threel movable sections 41, 49, and 5| are here illustrated, in addition to the fixed section 45. Each section except the forward section 5| has a relatively narrow inwardly `directed flange 6| (Fig. 5) at its forward end', and a second inward flange 63 ya littletothe rear of its forward end. Also, .each sectionexcept the rear xed section 45 has an 'outwardly directed flange 65 at its rear end. The periphery of the rear flange 65 of each section fits snugly but slidably withinl the vinterior diameter-of the next larger tube section, and the interioredges of the flanges 6| and 63 of each section fitsnug- 1y but slidably-on the exterior diameter of the next smaller section. Thus the sectionsL may move axially and telescopically with respect to eachother, the maximum limit of extension in each case being determined by engagement of the flange- 65 of the smaller tube with the flange 63 ofthe next larger tube, as indicated in Fig. 5. i. The forward end of the front guide tube section` 5| is provided with a somewhat wider inwardly directed ange-61 which is apertured and threaded to 'receive a screw 69 which fastens the bucking bar 53 to the front end of the tube section 5|.
. The rear end of the rearmost or xed tube section 45 is provided witha plug 1| held.y in place in V,any suitablel manner (for example, by the radialfscrews 13) through which plug is threaded a longnadjusting screw 15 which may be `turned by `-an external head 11 and held by a locknut 19. The forward end of this screw,y 15 bears against'a follower block 8| movable longitudinal- 1y inthe tube 45, which block thrusts forwardly against the rear end of a long coil compres,- sion spring 83,- which extends all the way through all of the tube sections and reacts at its forward 'end against the flange 61 at the front of the tube section 5|. lThe two springs 83 inthe two guides 4| and 43 thus constantly tend to push the bucking bar 53 forwardlyv to af position justin frontof the extreme front end of the saw chain (as shown in Fig. 7) in which position the respective fianges 63 and 65 of therespective guide sections are in contact with each other. But force exerted'rearwardly against the bucking bar `53 (as for example when thesaw is thrust forwardly against a tree limb or other objectlwill telescope the guide tube vsections within each other and will cause the bucking bar to move rearwardly to some such position as illustrated in Fig. 3. The degree of resistance to rearward movement of the bucking bar can be varied by adjustingthe screws 15.,
Surrounding the saw chain and thetelescopic guides 4| and 43 in transverse enveloping relationithereto, is a telescopic guard casing having a plurality of sections movable relative to each other as the bucking bar moves forwardly or rearwardly. Any desired number of lsuch guard sections may be used, there being eleven such sections in the form here illustrated, numbered from the largest rear section to the smallest front section, respectively, by the numerals 89 to 99, inclusive.
The front section.99 is secured 4 to the rear face of the bucking bar 53 by means, for example, of screws l0! passing through inturned flanges at the front end of the section 99, and threaded into the rear face of the bucking bar. The rear section 89 is fixed by brackets |05 to a plate |01 which extends between and is fixed to the upper and lower guides 4| and 43, as seen in Fig. 8. In longitudinal cross section` (viewed as in Fig. 1) each guard casing section 89 'to `99,"inclusive, is slightly tapered, with its larger end rearwardly, and lwith the ,larger end of each section fitting suiciently snugly in the smaller end of the next larger section so as to prevent complete withdrawal of each section from the next one. In transverse dimensions (viewed as in Figs. 8 and 9, for examp le) each section has approximately flat side w'alls vand'appro'ximately semicircular top and bottomv walls, of a size to enclose completely (in a transverse sense) the guide tubes 4| and 43 and the saw mechanism between them. l
The springs 83, normally extending the guide tubes to their forward positions, will likewise extend the guard casing sections 89 to 99 to their guarding or protecting positions shown in Figs.. 1, 2, and 4, wherein the forward part `of the chain saw is completely enclosed and any lateral movement of the saw toward an object will simply'result inl engagement of the object with the exterior of one or another of the casing sections 89 to 99, without causing any cuttingof or other damage to such object.- But if it is desired purposely to cut some object, such as the log or limb'indicated diagrammatically at lll in Fig. 3, then the saw, instead of being moved laterally into engagementwith the log- |||,4 is moved longitudinally into engagement Awith it. The `Alongitudinal lthrust will cause rearward pressure ofthe log' against the front face of the bucking bar 53,- which `will telescopically col-A lapse the `guide tube sections 41-5I andthe protecting casing'sections'S-SS to asufficient -ex; tent so that a sufficient part of the-chain savia projects beyond vthe front faceof the ybuckingv bar, to effect the desired-cut. A Thisis well illus-Y trated inFig; 3, and the collapsed position ofthe parts'is shown in'greater detailirl-Fig.V 6. soon as the -cutis" -completed `andthe .saw'fis lifted so that the bucking bar 53 is no longer-in contact with thefobject the^springsi83 auto-y matically and immediately :restore the guide partsfand protecting casing parts vto -their forward positions, fully protecting ythe saw from J accidental contact with any other object. f ,f ."An arcuate guard plate |2| (Figari-3) extends around the rear side of the sprocket 29 and Dro-l tects this part ofthe mechanism against acci.-v -dental contact, the top andv bottom endsof'the plate |2| being fixed to the tubes 4| `and 43;
As already mentioned, the guard parts ofthe present invention may be secured to the convene; tional saw'mechanism in any desired manner. Merely as an example, the parts of the present;- guardinechanismmay ybe supported-flargely or' entirely from the plate |01 (Fig. 8) whichfias abovestated, is in Iturn fixed to the tubes '4| and- 43 and flxedfthrough Itl'ie'braclsets |05,tothe, casing section 89. This plate |01,'inturn, mayY be secured lto any fixed p-arts of the conventional saw mechanism by'means of bolts or screws '125 (Fig. l) passing through holes |21 (Fig."8) fin" the plate |01and inito suitable fixed parts of the saw mechanism., Y -vg It is seen from the foregoing disclosureI that the above mentioned objects of the invention 'are well ffullled, It is to be understood that the foregoing disclosure is given by way of illustrative example only, rather than by way of limitation, and that without departing from the invention, the details may be varied within the scope of the appended claims.
What is claim-ed is:
1. A chain saw guard comprising a pair of guide members extending approximately parallel lto each other, each comprising a plurality of telescoping sections and adapted to receive an elongated chain saw between them, a front plate mounted on one end of said guide members and having an opening through which a chain saw may pass when said guide members are telescopically collapsed, and a guard structure associated with said guide members and front plate for protecting a cli-ain saw against lateral contact with an external obj ect.
2. A structure as defined in claim 1, in which said guard structure transversely embraces said guide members and a saw between said guide members.
3. A structure as defined in claim l, in which said guard structure includes a lplurality of tubular wall sections Itelesoopically arranged with respect to each other and embracing said guide members.
4. A structure as defined in claim 1, in which spring means is provided to urge said guide members and guard structure to maximum length.
5. A guard =for chain saws of the type including a fixed part and a toothed chain extending longitudinally in upper and lower reaches forwardly from lthe general Vicinity of said fixed part, said guard comprising a bucking bar extending generally transverse to the longitudinal directions of said upper and lower reaches of said chain, means for supporting said bucking bar from said fixed part for movement relative thereto in said longitudinal directions and for holding said bucking bar against substantial movement ltransverse to said longitudinal directions, and collapsible and extensible guard means supported from and extending between said xed part and said .bucking bar for Iprotecting that part of the chain Cil wLhich is between said fixed par-t and said bucking bar from lateral contact with other objects, the buckingbar being directly connected to the fixed part independently of the guard means.
6. A structure as defined in claim 5, further including resilient means normally tending to move said bucking bar forwardly toward the forward end of said chain.
'7. A struc-ture as defined in claim 5, in which said bucking bar is connected to the fixed part by a plurality of tubular guide sections independently of the guard means and telesco-pically arranged with respect to each other and extending from said fixed part to said bucking bar.
8. A structure as defined in claim 5, in which said means for supporting said bucking -bar includes two groups of tubular guide sections, the sections in each group being telescopically arranged with respect to each other and extending from said xed part to said bucking bar, the guide sec-tions of one group being arranged on the outer side of one reach of said chain and the guide sections of the other group being arranged on the outer side of the other reach of said chain.
9. A structure as dened in claim 8, further including a coil compression spring extending through the sections of each group and tending to move said bucking bar .forwardly with respect to said fixed part.
10. A structure as defined in claim 5, in which said guard means includes a plurality of ringlike members of non-circular cross section arranged in telescopic relation to each other and extending substantially from said fixed part to said bucking bar in embracing relation to the portion of said chain located between said fixed part and said bucking bar.
References Cited in the file of this patent UNITED STATES PATENTS Date