US3901117A - Saber saw and blade therefor - Google Patents

Abstract

A sabor saw device for attachment to a standard drill motor converts the rotary motion of the drill motor to reciprocating motion of a saw blade. The blade is locked to the reciprocable mechanism in a manner to prevent inadvertent disengagement of the blade while the saw is in operation. The blade and reciprocable mechanism are compatibly designed so that either a single ended or double ended blade may be mounted on the driving mechanism.

Description

United States Patent [191 Hoffman [451 Aug. 26, 1975 SABER SAW AND BLADE THEREFOR [76] Inventor: Simon J. Hoffman, 13115 E.

Jefferson St., Detroit, Mich. 48215 22 Filed: Aug. 16, 1973 211 Appl. No; 389,604

Related US. Application Data [60] Continuation of Scr. No. 88,090, Nov. 9, 1970, which is a division of Scr. No. 690,265, Dec. 13, 1967.

[52] US. Cl. 83/835; 83/750; 83/698; 30/392 [51] Int.Cl B27b 33/02 [58] Field ofSearch 83/750, 835, 698; 30/338, 30/339, 392

[56] References Cited UNITED STATES PATENTS 2,627,882 2/1953 Kleinsmith 30/392 Ilium 2,764,188 9/1956 Hoffman 39/392 Primary Examiner-Donald R. Schran Attorney, Agent, or F irmTownsend and Townsend [5 7 ABSTRACT A sabor saw device for attachment to a standard drill motor converts the rotary motion of the drill motor to reciprocating motion of a saw blade. The blade is locked to the reciprocable mechanism in a manner to prevent inadvertent disengagement of the blade while the saw is in operation. The blade and reciprocable mechanism are compatibly designed so that either a single ended or double ended blade may be mounted on the driving mechanism.

2 Claims, 17 Drawing Figures PATENTED AUE26I975 SHEET 1 [If 3 PATENTfinAuczsms SHEET 3 of 3 SABER SAW AND BLADE THEREFOR This is a continuation of application Ser. No. 88,090, filed Nov. 9, 1970 which was a division of application Ser. No. 690,265 filed Dec. 13, 1967.

BACKGROUND OF THE INVENTION The invention relates to reciprocating saw devices, and particularly to a novel blade for such a saw, a novel method of attachment of the blade to the mechanism which effects reciprocation of the blade, and to a novel reciprocating mechanism for the blade adapted to be attached to a standard drill motor.

Saber saw devices perform a cutting operation on metal or wood, and combine a relatively stiff-toothed blade with a mechanism for reciprocating the blade in order to do the cutting. One of the. problems with such devices has been the vibration and jarring effect of the reciprocating motor. It is accordingly one of the objects of the present invention to provide a driving mechanism for a saber saw device in which such vibration has been substantially eliminated.

The blade of a saber saw is reciprocated many hundreds of times per minute by the driving mechanism and as a consequence of the seemingly inherent vibrations set up by the driving mechanism, there is a tendency for the blade to become dislodged or detached from the driving motor during operation. This creates a hazardous condition because of the extremely rapid reciprocation of the blade. It is accordingly another object of the invention to provide a lock mechanism for the blade which will prevent its being disengaged inadvertently during operation.

When being used by an inexperienced person, it often happens that the blade of the saber saw is broken. This renders the device unusable unless the operator has another blade which he can substitute fdr thebroken one. It is accordingly a still further object of the present invention to provide s novel saber saw blade which is reversible in the driving mechanism so that if one portion of the blade is broken the opposite end may be substituted therefor.

The driving mechanism for a saber saw is in many instances self-contained; i.e., it has its own motor. This makes the device relatively expensive and in many cases prevents its purchase by people of limited means. Accordingly, it is a still further object of the invention to provide a relatively inexpensive driving mechanism which may be utilized in conjunction with a standard drill motor.

In the use of a saber saw, whether it is used for wood or for metal, one of the problems is the tendency of wood or metal chips to be drawn into the driving mechanism. Therefore, a still further object of the invention is to provide a driving mechanism for a saber saw which incorporates means for sealing the driving mechanism against the entry of chips.

Regardless of the type of driving mechanism for a reciprocating saw blade, it is helpful to have available a double-ended blade, either end of which may be quickly placed into operative position without the necessity of removal of the blade from the reciprocating drive member. It is therefore another object of this invention to provide a selectively rotatable platen on which a reciprocable saw blade may be detachably mounted.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described, as it may be embodied in various forms within the scope of the appended claims.

SUMMARY OF INVENTION In terms of broad inclusion, the saber saw device of the invention may be regarded in three different but related aspects. In one of its aspects the invention involves the provision of a novel reciprocating drive mechanism for a saber saw blade. In another of its aspects, the invention involves a novel blade useful with the novel drive mechanism of the instant design; and in its third aspect the invention involves the manner and means of detachably mounting the blade to the reciprocating drive mechanism.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a top plan view in elevation.

FIG. 2 is a side elevation of the saber saw device with a portion of the shield structure broken away to disclose the underlying parts.

FIG. 3 is a fragmentary side elevational view similar to FIG. 2, but showing in dash lines the blade release member swung into position to release the blade.

FIG. 4 is a fragmentary plan view similar to FIG. 1, but with a portion of the shield structure broken away to disclose the underlying parts.

FIG. 5 is a fragmentary elevation similar to FIG. 3, and illustrating the aperture in the shield member through which the blade release pin extends to release the blade from its support.

FIG. 6 illustrates one embodiment of a double ended blade suitable for use in the drive mechanism shown in FIGS. 1 through 5.

FIG. 7 is an illustration of a modified double ended blade, illustrating that either or both ends of the blade may be thinned considerably to permit cutting short radiuses.

FIG. 8 is another embodiment of the type of blade capable of being used in the drive mechanism.

FIG. 9 is a still further illustration of a different blade design.

FIG. 10 is a fragmentary side elevation illustrating the position of the blade just prior to rotation in the direction of the arrows to effect locking of the blade on its carrier member.

FIG. 11 is a vertical sectional view taken in the plane indicated by the line 11-11 in FIG. 10. This figure illustrates in dash lines the positional relationship between the blade and its carrier member just prior to rotation of the blade to bring it into locking position.

FIG. 12 is a side elevational view of the reciprocating drive mechanism, shown with the shield structure and blade carrier member removed to disclose the means by which chips are prevented from entering into the mechanism.

FIG. 13 is a vertical sectional view taken in the plane indicated by the line 13-13 in FIG. 12.

FIG. 14 is a side elevational view, partly in section, with the side cover plate of the drive mechanism removed to disclose the underlying structure.

FIG. 15 is a side elevational view of a modified embodiment of the blade carrier mechanism.

FIG- 16 is a vertical sectional view taken in the plane indicated by the line 16-16 in FIG. 15.

FIG. 17 is a side elevational view taken in the direction indicated by thearrow 17 in FIG. 16.

DESCRIPTION OF PREFERRED EMBODIMENT In terms of greater detail, the saber saw device of the invention comprises ahousing member 2, preferably fabricated from cast aluminum of relatively heavy cross-section, and having a hollow interior as shown best in FIGS. 13 and 14. Appropriately journaled within the hollow housing is a helically-toothed worm gear 3, driven by a helical worm 4 also suitably journaled in thehousing member 2. Attached to the worm 4 is anelongated drive stem 6 which projects out of the hollow housing for suitable attachment to a drill motor (not shown). Theworm gear 3 is provided with aface plate 7, and a suitable bronze bearing 8 rotatably disposed on stud shaft 9, secured to thewall 12 of thehousing member 2 by anappropriate nut 13. Acylindrical lug 14 is brazed on theface plate 7 adjacent its outer periphery and is adapted to rotatably engage thecentral bore 16 of aslide member 17. Because of its placement adjacent to the outer periphery of theface plate 7, lug 14 will be observed to follow a circular path upon rotation of theworm gear 3 and attachedface plate 7. The radius of such circular path is equal to the distance between the axis of rotation of theworm gear 3 and the central axis of thelug 14.

In order to translate the circular motion of thelug 14 into linear reciprocatory motion, theslide member 17 is slidably disposed within a vertically disposedchannel member 18, shown best in FIGS. 13 and 14, so that upon circular rotation oflug 14, theslide member 17 is caused to reciprocate longitudinally within thechannel member 18. However, sincelug 14 shifts its position transversely with respect tochannel member 18, it will be observed that in order to enable reciprocating movement ofslide member 17, thechannel member 18 must also follow the transverse movement oflug 14. In order to effect such transverse movement ofchannel member 18, one end thereof is slidably guided along abar member 19, the opposite ends 21 and 22 of which are suitably seated within shoulders formed in thehousing member 2 and secured thereto in a manner which will hereinafter be explained.

The other end ofchannel member 18 is rigidly brazed to atubular slide bearing 23 having an axis that extends perpendicular to the longitudinal axis ofchannel member 18, and which is adapted to slidably engage a guiding andsupport rod 24 as shown best in FIGS. 13 and 14. Theguide rod 24 has oneend portion 26 thereof detachably locked to thehousing member 2 by a screw 27 (FIG. 12) which passes through thehousing member 2 and engages a notch 28 (FIG. 14) formed in therod 24. Intermediate its ends, therod 24 is provided with a second notch 29 (FIG. 14) which is suitably engaged by a screw 31 (FIG. 12) which passes through the opposite comer of thehousing member 2 from thescrew 27. From this intermediate position of the rod, the rod extends outside of the housing in anabutment portion 32. Theother end portion 33 of the rod is bent back so that it lies parallel to theportion 24 of the rod, and is inserted in an appropriate aperture formed in thehousing member 2.

To insure that there is no binding ofchannel member 18 onslide bar 19 androd 24, thereciprocating channel member 18 is further supported and given stability by a rotatable wheel 34 (FIGS. 11 and 14) journaled on aplate extension 36, oneend 37 of which extends downwardly and is brazed to thetubular bearing member 23, while its opposite end is jogged to provide aflange 38 between which and thechannel member 18 thebar 19 is slidably interposed. Thewheel 34 is provided with a V-groove as at 36 which rollably engages therod 24 as shown best in FIG. 11. It will thus be seen that through the cooperation ofbar 19,rod 24 and bearingmember 23 thereon andwheel 34, thereciprocating channel member 18 is precluded from binding due to any transverse thrust imposed upon it by circular rotation oflug 14.

As shown best in FIG. 11, thewheel 34 is rotatably journaled on theplate 36 by a tubularstud shaft member 39, closed at one end by aplate 41, and at itsother end 42 enlarged in diameter as shown to provide a shoulder bearing againstplate 36. The open end ofenlarged portion 42 is butted against a transversely extendingplate 43 constituting a support platen for attachment of the saber saw blade to the driving mechanism. Theplate 43 is provided with acentral aperture 44, through which projects alock pin 46 resiliently retained in position bycoil spring 47 working betweenplate 41 and an enlarged end-portion oflock pin 46. Thetubular bearing portion 42 is surrounded and embedded in amember 48 of relatively heavy crosssection disposed between theplate 36 andplaten 43. As shown best in FIG. 12, the heavycross-sectional member 48 is provided at opposite ends with relatively sharp chisel-shaped edges as at 49 and 51. The chiselshaped edges function in a manner which will hereinafter be explained.

Closing thehousing member 2 is acover plate 52, shown best in FIGS. 12 and 13. The cover plate is conveniently fabricated as a three-part composite structure or assembly, including an outside closure member orcover plate 53, preferably fabricated from sheet aluminum and configured to conform to the outline of thehousing member 2. Underlying and secured to thecover plate 53 is aretention plate 54, between which and thecover plate 53 is sandwiched a sheet ofpolyurethane 56 or other flexible material. Thecover plate 53 andretention plate 54 are apertured as shown best at 57 in FIG. 12, but thepolyurethane sheet 56 extends across the aperture and is provided with aslit 58 as shown. The heavycross-section support member 48 which functions to support theplaten 43 extends through theslit 58 in theflexible polyurethane member 56, and the relatively sharp chisel-edges 49 and 51 serve to displace the opposed edges of the polyurethane sheet transversely of the direction of motion of theplaten 43. It will thus be seen that upon reciprocating motion of the sharpenedmember 48, the flexible polyurethane sheet falls together behind it so as to preclude the entrance of chips into the reciprocating mechanism. In other words, theflexible sheet 56 functions as a curtain which permits passage therethrough of theheavy support member 48, but which closes immediately behind the moving member.

As shown best in FIGS. 2, 4, 11 and 13, thebladesupporting platen 43 is provided adjacent one of its edges with alug 61 having ahead 62 thereon. Adjacent its opposite peripheral edge portion theplate 43 is rolled over to provide atab 63 lying parallel to theplate 43 but spaced therefrom a small amount to provide for the interposition therebetween of asaw blade 64. Thesaw blade 64, as shown in FIGS. 1, 2, 3 and 4, is similar to the embodiment illustrated in FIG. 6, which shows a full length blade having opposed ends of similar. configuration and having a centrally disposed aperture66 adapted to be engaged by thelock pin 46 which projects through theplate 43, Formed inopposite edges 67 and 68 of thesaw blade 64 arenotches 69 and 71, respectively, thenotches 69 and 71 andthecentral aperture 66 in the blade being in alignment or lying along a common axis, each such notch extending into a side edge of the blade, with the side edge havingcontinuous stretches 73 and "75 on opposite sides of the notch (FIG. 6) so .that the notch is independent of and spaced from sawteeth formed on such side edge of the blade.

To detachably engage theblade 64 to its carrier member orplaten 43, as shown best in FIGS. 10 and 1 1, the blade is positioned so that the notch 71 engages the shank of lug'61. The blade is inserted so that thelong edge 67 of the blade lies substantially parallel to aninclined edge 72 formed onflange 63. With the blade in the position shown in FIG. 10, the blade is pressed inwardly against the resilience imposed byspring 47 onpin 46, until theedge 67 of the blade passes beyond theedge 72. The blade may now be rotated in the direction indicated by the arrows in FIG. 10, using the shank ofstud 61 as a fulcrum, until theupper edge 67 of the blade becomes engaged behind theflange 63. From an examination of FIG. 10 it will be noted that with the blade in the inclined position shown in that figure, the centrally disposedaperture 66 in the blade lies transversely displaced from thepin 46. With rotation of the blade aboutshank 61, the centrally disposedaperture 66 is swung into indexing relationship with thelock pin 46. When theupper edge 67 of the blade has become lodged behindflange 63, it will be found that thepin 46 will snap into the centrally disposedaperture 66 in the blade. The blade in this locked position, as shown best in FIG. 2, lies detachably locked behind thehead 62 oflug 61, and behind theflange 63. The shank oflug 61, cooperating with the notch 71, prevents longitudinal movement of the blade with respect to the actuating mechanism, while thehead 62 oflug 61 andflange 63 prevent lateral displacement of the blade with respect to its direction of motion during operation. Additionally, insertion of thepin 46 in thecentral aperture 66 of the blade prevents rotation of the blade as would be required to disengage theedge 67 from behindflange 63. Accordingly, theblade 64 is securely yet removably attached to theplate member 43.

In FIGS. 7, 8 and 9, there are shown different embodiments of blades which may be used with the actuating mechanism described above. Theblade 76 shown in FIG. 7 is provided withopposed blade portions 77 and 7 8 having a transverse width substantially less than the width of theblade 64. Such a narrow blade has the advantage of being able to be used to cut relatively short radiuses. Each of theblade portions 77 and 78 extend in opposite directions from a centrallydisposed body portion 79 of the blade, one edge of which is provided with anotch 81 similar to thenotch 69 inblade 64, while the other edge portion of the body is provided with anotch 82 similar to the notch 71 inblade 64. As shown in the drawing, thenotches 82 and 82 bear the same relationship to thecentral aperture 82 inblade 76 as exists between corresponding elements inblade 64.

Theblades 84 and 86 illustrated in FIGS. 8 and 9, re-

spectively, are each provided with a central body por tion v187, acentral aperture 88, and anotch 89 formed along one longitudinal edge in the body portion of the blade. Each of these bladesis attached to thebladesupporting plate 43 in the same manner asblades 64 and 76. The difference between the blade shown in FHG. 8 and the blade shown in FIG. 9 is that the cutting portionof the blade 86 in FIG. 9 is of less width than theblade 84 in FIG. 8. In the construction of the device shown in FIGS. 1 through 14, in order to substitute one end of the blade for the other on the device, it is necessary to remove the blade and reinsert it and re-lock it in position with the opposite end of the blade projecting as in FIGS. 1 and 2. To facilitate this operation (FIGS. 1 through 3) there is provided aspring finger 91, pivotally supported on ascrew 92 which functions also to retain thecover plate 52 in position. Thespring finger 91 is equipped with an extending lock-release portion 93 adapted to be inserted through an aperture 94 (FIG. 5) and placed in contact against the end oflock pin 46. Theaperture 94 is formed in theside member 96 of a guard and coverplate 97 as shown best in FIGS. 1 and 2. Thespring finger 91 is shown in dash iines in FIG. 3 in position to release thelock pin 46 from the blade. It will thus be seen that upon depression of the spring pressedlock pin 46, the saw blade may be rotated in order to swing theupper edge portion 67 ofblade 64, for instance, from under theflange 63, thus permitting the blade to be removed.

In the construction of the device shown in FIGS. 15, 16 and 17, theplaten 43 shown in FIGS. 1 through 14 is modified in order to permit rotation of the blade endfor-end without removing the blade from the support member. Referring specifically to FIGS. 15 and 16, it will be seen that the blade-support platen 101 is provided with aperipheral flange portion 102 which is spun over the edge portion of acarrier member 103. The edge portion of thecarrier 103 over which theflange 102 is spun is conveniently conically shaped as shown in order to permit rotation of theplaten 101 on thesupport member 103. As withplaten 43, theplaten 101 is provided with alug 104, having ahead 106. Additionally, as withplaten 43, theplaten 101 is provided with aflange 107 which cooperates with theplaten 101 to lock theblade 108 in position on the platen. As before, a spring-pressed detent or lockedpin 109 engages acentral aperture 112 shown in dash lines in FIG. 15. To lock theplaten 101 against rotation on its supportingmember 103, opposite peripheral edges of theplaten 101 are provided withnotches 113 as shown best in FIGS. 15 and 16, and the supportingmember 103 is provided with aspring arm 114, shown best in FIG. 16, on the end of which there is alock lug 116 adapted to engage thenotches 113 as they are brought into registry with thelug 116. It will thus be seen that in order to rotate theblade 108 end-for-end, the lock pin release lever 117 (P16. 16) is swung in an arc as shown by the arrow in FIG. 17, to cause a lock-pin release-lug 118 to extend throughaperture 119 in anappropriate cover plate 121. When thelock lug 116 has been sprung back into the position shown in dash lines in FKG. 16, the saw blade may be rotated freely with theplaten 101 on thesupport member 103. As with the other embodiments, it is possible to remove thesaw blade 108 from theplaten 101 by swinging thespring lever 117 so as to bring thelug 118 into registry with theaperture 122 in thecover plate 121 so that thelug 118 may impinge against the spring-pressedlock pin 109. Depressing the spring-pressed lock pin enables rotation of the saw blade aboutlug 104 as a center of rotation so as to swing the edge of the saw blade out from underflange 107.

I claim:

1. A saber saw blade for a drive mechanism having a reciprocal platen provided with a fixed lug and a spring biased pin spaced from the lug and offset relative thereto in one direction of reciprocation of the platen, said blade comprising: an elongated metallic strip having a body portion adapted to be coupled with the platen and a working portion integral with the body portion and extending away therefrom, said body portion having a pair of opposed side edges and an aperture therethrough, the aperture being disposed generally midway between the side edges of the body portion, said working portion having a side margin coextensive with a first of the side edges of the body portion,

there being a series of sawteeth along said side margin of the working portion, and a lug-receiving notch formed in the second of the side edges of the body portion and being offset relative to the aperture in the opposite direction of reciprocation of the platen, said first side edge of the body portion having continuous stretches on opposite sides of the notch, said blade being removably positionable adjacent to the platen with the lug of the platen received in the notch and the pin of the platen received in the aperture.

2. A saber saw blade as set forth inclaim 1, wherein a pair of working portions are provided on said strip, the body portion being disposed between the working portions so that they extend therefrom in opposite directions, there being a second lug-receiving notch formed in the body portion in the first side edge thereof and offset axially therealong on the opposite side of the aperture so that both notches and said aperture lie along a line angularly disposed with respect to the longitudinal axis of the strip.

Claims (2)

1. A saber saw blade for a drive mechanism having a reciprocal platen provided with a fixed lug and a spring biased pin spaced from the lug and offset relative thereto in one direction of reciprocation of the platen, said blade comprising: an elongated metallic strip having a body portion adapted to be coupled with the platen and a working portion integral with the body portion and extending away therefrom, said body portion having a pair of opposed side edges and an aperture therethrough, the aperture being disposed generally midway between the side edges of the body portion, said working portion having a side margin coextensive with a first of the side edges of the body portion, there being a series of sawteeth along said side margin of the working portion, and a lug-receiving notch formed in the second of the side edges of the body portion and being offset relative to the aperture in the opposite direction of reciprocation of the platen, said first side edge of the body portion having continuous stretches on opposite sides of the notch, said blade being removably positionable adjacent to the platen with the lug of the platen received in the notch and the pin of the platen received in the aperture.

2. A saber saw blade as set forth in claim 1, wherein a pair of working portions are provided on said strip, the body portion being disposed between the working portions so that they extend therefrom in opposite directions, there being a second lug-receiving notch formed in the body portion in the first side edge thereof and offset axially therealong on the opposite side of the aperture so that both notches and said aperture lie along a line angularly disposed with respect to the longitudinal axis of the strip.

Images