US2547922A - Portable motor operated hand scroll saw - Google Patents

Description

p 1951 J. L. BECHTOLD 2,547,922

PORTABLE MOTOR OPERATED HAND SCROLL SAW Filed Jan. 30, 1948 3 Sheets-Sheet 1 Inventor 5 Joseph L Bach/old April 10, 1951 J. BECHTOLD PORTABLE MOTOR OPERATED HAND SCROLL SAW 3 Sheets-Sheet 2 Filed Jan. 30, 1948 Iuventar Joseph L. Bach/old and April 1951 J. L. BECHTOLD 2,547,922

PORTABLE MOTOR OPERATED HAND SCROLL SAW Filed Jan. 30, 1948 3 Sheets-Sheet 3 Fig. 3 53 Fig. 4.

4- m l/4. VIII/4 i Joseph L Bach/old Attorneys Patented Apr. 10, 1951 OFFICE PORTABLE MOTOR OPERATED HAND SCROLL SAW Joseph L. Bechtold, Roseburg, Oreg. Application January 30, 1948, Serial No. 5,279 I 3 Claims. (Cl. 14368) My invention relates to improvements in portable motor operated, hand scroll saws for cutting sheet material, especially, although not necessarily.

The primary object of my invention is to provide a simple form of inexpensive hand scroll saw with a motor drive and which is better adapted for scroll sawing sheet material than stationarily mounted scroll vsaws, is not liable to get out of order, and is designed for smooth operation with a reciprocating saw blade.

Other and subordinate objects, within the purview of my invention, together with the precise nature of my improvements will be readily understood when the succeeding description and claims are read with reference to the drawings accompanying and forming part of this specification.

In said drawings: I

Figure 1 is a view in vertical section, with parts shown in elevation, of my invention in a preferred embodiment thereof;

Figure 2 is a fragmentary view in vertical section taken on the line 22 of Figure 1;

Figure 3 is a fragmentary view in vertical section taken on the line 3-3 of Figure 2 with parts eliminated for clearness of illustration;

Figure 4 is a fragmentary view in horizontal section taken on the line 4-4 of Figure 1,

Figure 5 is a detail fragmentary view in plan, partly broken away and shown in section;

Figure 6 is a view in vertical section taken on the line 66 of Figure 1;

Figure 7 is a view in front elevation drawn to a smaller scale, andpartly broken away.

Referring to the drawings by numerals, according to my invention, as illustrated, a hand scroll saw is provided comprising a generally rectangularbase, shoe plate I with upturned front and rear ends 2, 3 adapting the same to be slid over sheet material to be sawed.

The shoe plate I has formed thereon, adjacent what constitutes the outer side edge of the same, an aperture 4 in which'the usual saw blade 5 is reciprocated vertically, by means presently described, in a plane at a right angle to the plane of said plate. Between the aperture 4 and the rear side edge of said plate I is an elongated cast bracket 5 upstanding from said plate to extend longitudinally thereof parallel with the side edges of the plate and terminating at the rear end of said plate I in a loop handle I. Screws 8 secure the bracket 5 on said plate I.

A motor casing 9 of generally cylindrical shell form, with a closed rear end I0, and internal front end lugs II, extends endwise across the bracket 6, and across said plate I, forwardly of the handle 1 and has a pending bottom lug I2 pivoted by a pivot pin I 3 in said bracket 6 so that the motor casing 9 is tiltable vertically about an axis transverse to said plate I and parallel with of said plate over the work. A suitable wing head latching bolt I4 threaded into the bracket 6 to be turned against the lug I2 is provided for retaining the motor casing 9 in different tilted positions, for a purpose presently seen.

A substantially annular plunger head I5 with an open front side I5, vertically aligned top and bottom bosses II, I8 thereon and a closed rear side I9 is fixed to the front end of the motor casing 9 concentrically thereof by screws 20 passing through said side I9 and into the lugs II. A closure plate 2| is secured to the front side I5 of said head I5 by screws 22. As will be seen, the described head I5 is tiltable with the motor casing 9.

An electric motor 23 is secured in the motor casing 9 with its armature shaft 24 coaxial with that of said casing and running in a bearing 25 provided in the rear end ID of said casing 9 and adapted to be lubricated through an oil plug 26. Lugs 21 on the front end of the motor 23 are bolted, as at 28, to a cross support 29 in said the line of movement motor casing 9.

A train of reduction gearing 30 in the front end of the motor casing 9 operatively connects the armature shaft 24 to a short driven shaft 3| journalled in the rear side I9 of said head I5 in axial alignmentwith said shaft 24. duction gearing 30 comprises a pair of relatively small and large driving and driven gears 32, 33 fast on the, armature shaft 24 and driven shaft BI and a pair of reduction gears 34 meshing, respectively, with the gears 32, 33 and fast on a shaft 35 journalled in the cross support 29 and in abearing 36 in said casing 9.

,An eccentric 3'! is fast on the front end of the driven shaft 3|, in said head I5, in the rear of the head, also a fly wheel 38 between the eccentric 31 and the rear side I9 of said head I5 suitably counter weighted, as shown at 39, to counter balance the eccentric 31.

The eccentric 3! fits and revolves between a pair of vertically spaced collars 40 fixed by pins 4| on a verticalplunger shaft 42 arranged to reciprocate and rotate in the vertical axis of the head I5 and the aperture 4 with its lower end extending through and below boss I8 by way of a guide bore 43 in said boss, said saw blade 5 being secured in a vertical slot 44 in the lower end of said shaft by screws 45.

. The plunger shaft 42 terminates at its upper end in said head I5 and is rotatable in said bore 43 and in a pair of upper and lower sectional cap bearings 46, 41 secured together and to the rear side I9 of the head I by bolts 48. Lubricating glands 49', 50' are threaded in the upper and lower bearings 46, 41 against packing 49, 50.

A pair of upper and lower expansion coil springs 5|, 52 surround the plunger shaft 42, one inter- The remediate the upper collar 40 and the bearing 46, and the other intermediate the lower collar 40 and the gland 50, and which balance said shaft in an intermediate normal position.

Means are provided for setting the plunger shaft 42 into different angular positions, by rtating the same to correspondingly set the saw' blade and now to the head I5 is a hand wheel 53 fast on the upper end of a saw setting shaft 54 vertically aligned with the plunger shaft 42 and'havingxa lower squared end 55 slidable in a square axial socket 56 provided in the upper, The saw setting shaft 54*is rotatable in a packin'g gland 51 set into the upper b'oss- H with the setting shaft 54'extending therethro'ugh into said head 15. A cap plate 58 on said bossll secured thereto by screws 59*retains th'e' packing gland 51 in its place. A collar BO 'fixe'd to said'shaft 54 as at 66 and forming 51 prevents upward thrust of said shaft 54. A hub 6l-on the hand wheel 53 prevents downward play' of said shaft 54; A cam 62 with a hand lever 63 thereon is pivoted as'at 64, on top of the cap plate 58 to be wedged against the hub 61 and thereby hold the hand wheel53, the saw setting shaft-54, and plunger shaft 42 and saw'blade 5 in different'set positions irf which the saw blade 5 is oblique to the line of movernent ofthe shoe plate I. v I

A suitable switch 55 operated byafinger piece 66-is provided on thehar'idle 'l for controlling the motor 23 which may be provided with the usual plug in leadcables, not shown;- for connection to a wall socket, or'the like, not shown. 7

In operatingthe described hand scroll saw, the same is pushed along the work, not shown, with the shoe plate I sliding over the work; motor 23 running} the plunger shaft is reciprocated with the saw blade 5 by the eccentr'ic'3'l working between the collars and in opposition to the springs 52,52 which'te'nsion said shaft 42 against movement in opposite directions'fr'om in termediate positions so that said springs function in reciprocating said' plunger shaft and to take part of the load off' themotor 23. The-described reduction gearings' 30" provid'e'jfor theuse of a' high speed motor 23 with" slower reciprocation of the saw'5 as will be apparent; During recipro cation of the plunger shaft42, the same slideson the squared end 55 of the saw setting shaft 55. By setting the hand wheel 54, in the manner described the saw blade 5 may be adjusted to different angular positions 111 scroll sawing, or

like work. By tilting the motor casing 9into dif ferent set positions on thepiris' -l3, and asdetermined by use of be correspondingly tilted 42 and the saw blades 5 laterally of-the'lineof the cut as occasion may require in scroll sawing Work.

The foregoing will, iti's believed, suffice to impart a clear understanding of my invention, without further explanation.

Manifestly, the invention, as'described, is sus'-' ceptible of modification, without'departing'from the inventive concept, and'right is herein re served to such modifications'as fallwithin the scope of the appended claims.

Having described my invention, as new is:

what is claimed be described. At the top of end of said shaft 42' part of the said-gland With the' locking bolt IA, the'head |5 may to tilt the plunger shaft ed to extend out of the head, a saw 1. In a saw of the class described, a motor cas-' ing having a motor therein, a hollow head fast on said" casing, 'a reciprocating and rotatable plunger shaft in said head having one end adaptblade fixed to' said end of said shaft in longitudinal alignment therewith', a drive between said motor and shaftfor reciprocating said shaft, a shoe plate for sliding movement over the work, means to 'rrioun't said casing on said plate for tilting of the sam'e together with said head, shaft and blade laterally of the line of movement of said plate, and'means to rotate said shaft into different set angular positions to correspondingly set said blade in different oblique-positions relative to theline of movement of the plate.

2. In a saw of the class described, a motor casing having a motor therein, a hollow head on' said casing, a reciprocating and rotatable plunger-shaft in said head having one end adapted to extend out of the head, a saw blade fixed tosaid end of saidshaft'in longitudinal align-- ment therewith, a drive'between said motor and shoe plate for'saidcasi'ng and head and for slid ing movement ov'er the work, and means connected to; the opposite end of said-shaft for rotating the-same into different angular set positions to correspondingly set said blade into different oblique positions relative to the line of movement of said plate comprising a hand wheel rotatable on said head, a setting shaft'rotatable by said wheel and splined in said opposite end of the plunger shaft, and a pivoted cam on said head for locking said wheel.

3. In-asaw of the class'describ'ed, a motor casing having a motor therein, a hollow head on sai'd'ca'sin'g', a reciprocating and" rotatableplunger shaft in said head having one end adapted to ex tend out of the head, a saw blade'fixed to said end of said shaft in longitudinal alignmen't'therewith, a drive between-said motor and-Shaftfo'r reciprocating the shaft; means supporting said casing and head for work, and means connected tothe' opposite end of said shaft for rotating thesame into different angular set positions to correspondingly set said blade into different oblique position's'relative tothe line of movement of said head comprising a handwheel rotatable on said headymeans con necting said wheel-to said shaft to rotate'said' shaft while reciprocating and by rotation ofsaid wheel, and a pivoted cam-on said head' for lock-- ing said wheel.

. JOSEPH nBEcn'roLD.

REFERENCES; CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 7 Name Date 216,245 Warth June 3,- 1879 620,847 Jackson Mar; 7, 1899 824,948 Pollock July 3, 1906 1,707,097 Ruschke Mar. '26, 1929 1,808,228" Hula'ck'et al June'2, '1931 1,974,642 Colby Sept. 25, 1934 sliding movement over the

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