US1850444A - Portable motor driven saw - Google Patents

Description

March 22, 1932. H. P. BRUMELL PORTABLE MOLI'OR DRIVEN SAW Filed Sept. 17, 1950 2 Sheets-Sheet Qm. Wm.

March 22, 1932. H P, BRUMELL L PORTABLE MOTOR DRIVEN SAW Filed Sept. 17. 1950 2 Sheets-Sheet gwuentoz Haig PEM/a PatentedA Mar.4 22, 1932 UNITED l STATES ,PATENT OFFICE HARRY BBUMELL, OF NEW'BRITAIN, CONNECTICUT, ASSIGNOR TO THE STANLEY WORKS, OF NEW BRITAIN, CONNECTICUT, A CORPORATION 0F CONNECTICUT PORTABLE Moron naIvnN saw Application led September 17, 1930. Serial No. 482,438.

and which Crowe `patent and application have been assigned to the same assignee as the present application.

A tool of the class to which reference is had may comprise a frame, a cutting bladey operatively mounted thereon and a motor on the frame for operating the blade; guarding means (which may be referred to, for convenience, as the bottomA guard) movably mounted on the frame to advance and recede to guard or expose a cutting portion ofthe blade, and which bottom guard comprises or includes a base adapted to engage and travel along the work; automatic means, such as a spring, effective in all tool positions" and tending to advance the bottom guard to guarding position, andreleasable means also eective in all tool positions for automatically securing` the bottom guard against retreat. The last. mentioned means` may lbe operated. bythe engagement ofthe work with an' element carried by the tool so as to permit the'guard to retreat. l L v A primary object of the'present invention is to` provide a tool of this sort which isv lighter in weight, which comprises a fewer numberV of parts, which has a neater and more pleasing appearance, and wherein vthe guarding means for the upper portion of the saw is so arranged as to follow generally the 40 curvature of the saw so that objectionable humps or projections, which would interfere with the operator observing the. forward end of the tool and the line along which thev tool should be moved, are eliminated.

l In accordance with the present illustrative disclosure of my invention, the bottom guard carries a movable front guard which is adapted to cooperate with the fixed or top guard so as to releasably hold the bottom guard in proteetin'gor advanced position, the front guard 4advanced or guarding position;

being associated, by preference, with trip mechanism adapted to engage the work for the purpose of releasing the front guard from the fixed guard and thus permitting the bottom guard to recede. The top and front uards are adapted to relatively telescope into one another, and these guards follow, more or less closely, the curvature of the saw so that they do not present any unsightly humps or projections which would interfere with the operator observing the forward end of the tool.

Other objects will be in part obvious andl in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangements of parts which will be exemplified in the construction hereinafter set forth and the scope of the application of 'which will be indicated in the appended claims. y

In the accompanying drawings, wherein I have shown, for illustrative purposes, one of the many .embodiments which the present invention may take:

' Figure 1 is a side elevational view of a tool in which my invention is incorporated, the bottom guarding means being shown in full Fig. 2 is a top plan view of the forward end of the tool;

Fig.k 3 is a view, partly in elevation and partly in section, and is taken on line 3 3 of Fig. 1,; and

`ig. 4 is a side elevational view of the forward end of the tool, the bottom guard being shown in receded position so as to expose the lower portion of the cutting blade.

Referring to the drawings in detail, 10 designates generally a' frame which carries a motor 11 having a shaft 12 to which is fixed a cutting blade 13. The casing 10 may house the connections between the motor and the shaft 12, these connections not being shown as they may be similar to those disclosed in said Crowe patent and they form no part of the present invention. The frame also includes a fixed guard 14 which may be formed integrally with the casing or frame. This guard 14 encloses the upper 'portion of the saw and, therefore, may be referred to, for convenience, as the top ard. The rear end of the motor carries a andle and, if desired, a second handle 16 may be provided,

The bottom guarding means may comprise a single member constltuting a base adapted to and travel along the work, as shown in said 'owe Patent No. 1,644,326,- or it may comprise, in combination, a guard element and a runner or base mounted for adjustment about an axis longitudinal of the cut, the latter arrangement being shown in the drawings by way of illustration only. This a ent is also shown 1`generally in said Crowe application Serial o. 327,542. The guard element is designated by the numeral 20 and is pivoted to the frame 10 as at 21. The endsV of the guarding element 2O have flat faces 22. The runner or base is designated b the numeral and has, adjacent each en upstanding ears 26 adapted to rectively engage against the flat faces 22. e runner has a flat work engagin bottom surface which is slotted as at 27 1n t e plane of theV saw blade to clearthe same. The runnermay be mounted on the guarding ele- .ment 20 for ad'ustment thereon about an axis longitudinal o the cut in a manner similar to that disclosed in said Crowe application. The runner may be clamped in a justed position b a thumb nut 28.

The ont guard which, when the tool is in inoperative ition, guards the forward end of the saw bgween the to bottom, guard, is designa by thenumeral 35 and is pivoted by a pin 36 to the guard elecross section and, at its lower end, straddlesment 20 adjacent the latters forward end.

The pivot 36 is carriedby a pair of ears or `lugs 37 (sce Fig. 3) located on a raised or arched portion 38 of the guard velement. 20. The front 'guard 35 is generally of U shape in the raised portion 38 of the guard element 20.y The front ard 35 is open at its up er end and is slig tly wider than the fixe guard 14 so that the latter may telescope into the former, as shown in Fig. 4, when the bottom ard recedes. The top guard has, at its orward end, a shoulder or stop 39 which is adapted to en ge upon the sto or shoulder 40 provided the upper en of the connecting portion ofthe frontguard. When the parts are in the Position shown in Fig. 1, the forward end o the top guard projects slightly into the upper end of the front one; the topguard rests upon the upper end of the front guard, and the outer peripheries of the two guards, where they meet, are substantially flush. The front guard is normally urged rearwardIly, that is to the locking position'shown in ig. 1, by a spring 45 coiled about the pin 36 and having its opposite guarding means is normally urged tothe adguard and the the slot 27 in the base or runner 25. Pivoted to the front ard, as at 53, is a connecting lever 54, the diwa rd end of which rests upon the cam 51. The rear end of the connecting lever rests upon a stud on the guarding element 20. The coiled s ring 56 normally ur es the tri lever to t e position shown in igs. 1 an 3.

For they urpose of limiting the extent to which the'rbottom guarding means may recede, and thus determine the depth of cut which the saw will take, there may be provided a rod 60 carried by the guarding element 20 and curved about the axis 21 about which the bottom guarding means swings. The upper end of the rod 60 extends slidably through a boss 61 on the top guard and, on the upper projecting end of therod, 1s a nut 62 which limits the extent to which the bottom guarding means vcan be moved to advancedor protecting position. Carried b the rod 60 between the boss 61 and the ar ing element y 20 is an adjustable col ar'- 63 ada ted to be secured in any predetermined position of adjustment by a screw 64.

The manner in which my improved tool operates is clear from the fore omg descriptlon taken in connection wit the accompanyin drawings.v It will be observed that, when t e tool is not being used, the bottom guarding means is in advanced or protectin position and it is releasably held in that os1 tion bythe front guard 35 due to the loc ing engagement between the upper end of that uard and the shoulder 39 on the to guard. he .trip lever is in the position w ere the trip element 50 extends downwardly below -the work engagingvface of the runner 25.

When it is desired to use the tool, the forward, end of thek runner is positioned on the surface of the work to be o erated upon and then the tool is advanced y means of the handles 15 and 16. When thus advanced, the trip lever will engage the edge of the work causing the cam 51 to raise theforward end of the ever 54 with the -result that the upper end of the front guard will swing forwardly and out of engagement with the shoulder 39. The bottom guard will then recede, or, what amounts to the same thing, the saw will be moved down through the slot in the runner, as shown in Fig. 4, and, during this movement, the top guard telescopes into the front one. As soon as the tool is moved from the los l and also acts as a latch or means for releasably holding the bottom guard in. advanced position. The trip mechanism comprises but a relatively few number of parts and, therefore, may be embodied in the tool at a relatively low cost and it is also very effective in operation. It will further be -seen that the top guard closely follows the curvaturev of the saw and that it is devoid of unsightly and inconvenient humps or projections.

As many changes could be made in -the above construction and many apparently Widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

I claim as my invention:

1. In a tool of the character described a unit including a frame, a cutting blade operatively connected thereto, and a motor for operating said blade; guarding means movably mounted on said unit to advance or retreat to guard or expose a cutting portion of said blade, a guard carried by and movable relative to said guarding means and arranged to protect the forward portion of the blade, cooperating shoulders or stops on said unit and guard respectively adapted to interengage to hold said guarding means against retreat, and means normally urging said guard in a direction to engage said shoulder.

`2. In a tool of the character described, a frame, a cutting blade operatively mounted thereon, a fixed guard carried b said frame and having a shoulder at its orward end, guarding means movably mounted on said frame to advance or retreat to guard or expose a cutting portion of the blade, a front guard movablj7 carried by said guarding means and havmg at its upper end a shoulder adapted Vto cooperate with the shoulder on said fixed guard to hold said guarding means against retreat, said fixed guard being adapted to telescope into said front guard upon retreat-of said guarding means, and means normally urging said front guard ina direc-I tion to engage the shoulders.

3. In a tool of the character described, a Y

frame, a cutting blade operatively mounted thereon, a fixed guard protecting the uppery portion of said blade and curved generally concentrically vthereto and having a stop or 1 shoulder at its forward end, a bottom pivoted at its rear end and adapted to adard vance or retreat to guard or expose a cutting portionof the blade, a.` front guard pivot adjacent its lower end to the bottom guard adjacent the forward end of the latter, the upper end of said front guard having a shoulder adapted to engage the shoulder on said fixed guard'to hold the bottom guard a ainst retreat, a spring normally urging sai bottom guard to protecting position, and aspring normally urging said front guard into latching position.

4. In a tool of the character described, a frame, a cutting blade operatively mounted thereon, guarding means movably mounted on said frame to-advance or retreat to guard or expose a cutting portion of said blade, 'a movable guard protecting a portion o f the blade not projecting into the work and itself constituting means for securing said guarding means against retreat from guarding position, and means for moving said guard from securing position.

5. In a tool of lthe character described; a unit including a frame, a cutting blade operatively connected thereto, and a motor for operating said blade; guarding means movably mounted on said unit to advance or retreat to guard or expose a cuttin portion of said blade, automatic means e ective in all tool positions and tending to advance said guarding means, a movable guard protecting the forward end of said blade and adapted to directly engage said'unit for holding said guarding means against retreat, and means for moving said guard from holding position.

, 6. In a tool of the character described, a frame, a cuttingblade operatively mounted thereon, a fixed guard carried by said frame, guarding means movably mounted on said frame to advance or retreat to guard or expose a cutting portion of said blade, a front,

guard movably carried by said guarding means and adapted in one position to direct-l ly engage said fixed guard to hold said guardtuting means for securing said guarding means against retreat, said guard being movable with respectk to sald guardmg means into andout of securing position, and means adapted for actuation by engagement with the work for releasing said guard from securing position.

8. In a tool of the character described; a unit .including a frame, a cutting blade operatively connected thereto, and a motor for operating said blade; guarding means movable on said unit to advance or retreat to` guard or expose a cutting portion of said blade, automatic means effective in all tool positions tending to advance said guarding means, a movable guard protecting the forward end ofA said blade and ada ted to itself directly engage -said unit for olding said uarding mzans a ainst retreat, and means, aving a portion adapted to engage the work, for moving said guard from holding position.

9. In a, tool of the character described, a frame, a cuttingblade operatively mounted thereon, a fixed guard carried by said frame, guarding means movably mounted on said rame to advance or retreat to guard or expose a cutting portion of said blade, a front guard mounted on and movable relative to said guarding means and adapted in one position to `itself directly cooperate with said fixed guard to hold said guarding means against recession, and means adapted for actuation by engagement with the work for moving said front guard from said positionv to allow said guarding means to retreat. 10. In a tool of the character described; a

- unit including a frame, a cutting blade operatively connected thereto, and a motor for operating said blade; guardingmeans movably mounted on said unit to advance or. retreat to guard or expose a cutting portion of the blade, a front guard pivotally mounted on said guarding means and adapted to engage said unit for holdingfsaid uarding means against retreat, and means or moving said front guard from holding position including a work-operated trip lever carried by said guarding means and an operative connection between said trip lever and said guard.

l1. In a tool of the character described, a frame, a cutting blade operatively mounted thereon, a fixed guard carried by said frame, guarding means movably mounted on said frame to advance or retreat to guard or expose a cutting portion of the blade, a front guard pivotally mounted on saidI guarding means and adapted to directly engage said fixed guard to hold said guarding means against recession, a trip lever pivoted on said guarding means and having ak projection adapted to engage the work, and a cam; and a lever between said cam and front guard whereby the front guard is moved forwardly out of holding position when the trip lever 1s moved by engagement with the work.

12. In a tool of the character described, a frame, a cutting blade operatively mounted thereon, a fixed guard carried by said frame a bottom guard movably mounted on said frame to advance or retreat to guard or expose a cutting portion of the blade, a front guard pivoted on said bottom guard, interengaging shoulders between the forward end ofsaid fixed guard and the upper end of said front guard adapted to cooperate to hold said bottom guard against retreat, said fixed guard being adapted to telescope into said front guard upon retreat of said bottom guard, means normally urging said front guard into holding position,a trip lever pivoted on said bottom guard and having a projection adapted to engage the work, and a cam; and a lever pivoted to said front guard and engaging said cam.

13. In a tool of the character described, a frame, a cutting blade operatively mounted thereon, guarding means movably mounted on said frame to advance or retreat to guard or expose a cutting portion of said blade,

automatic means effective in all tool positions and tending to advance said guarding means, a guard for protecting the forward portion of the cutting blade, said guard being movable with respect to said guarding means and adapted to cooperate with said frame to releasably Yhold said guarding means against retreat, and means normally urging said guard linto latching position.

14. In a tool of the character described, a frame having a fixed guard, a cutting blade operatively mounted on said frame, guarding means movably mounted on said frame to advance or retreat to guard or expose a cutting portion of said blade, and a front guard carried by and pivoted onsaid guarding means and having telescoping relation to said fixed guard, said front guard being movable into and` out of abutting relation with said frame.

15. In a tool of the character described, a unit including a frame, a cutting blade operatively connected thereto, and a motor for operating said blade; guarding means movv ably mounted on said unit to advance or retreat to guard or expose a cutting portion of said blade, and a guard movable relative to said guarding means into and out of engagement with a relativel fixed part of the frame to act as a latch, said guard protecting the forward end of said blade and adapted, when in latching position, to directly engage the relatively fixed part of the frame for holding said guarding means against retreat.

HARRY P. BRUMELL. i

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