US1527150A - Gear drive - Google Patents

Description

Feb. 17. 1925. 1752 1 J. M. LEAVER, JR 7 so GEAR DRIVE Filed Dec. 24. 1920 3 ShetS-Sheot 2 U R .O I N w m RMMHAIIIXHH/I/ ^\\l1/ www. .mw .,MUNMWH-fMHwwwlwwl/y ffff I I mm. i {--XIILHHUHHHy en m d L u l w M m Y g l a E "Il" SN.. Il-

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@EAR mmm Filed Dec. 24. 1920 'VW Q Y ATTORNEY fifi Patented Feb. 17, 1925..

UNITED GEAR DRIVE.

Application filed December 24, 1920.

To all Iifi/wm t may concern.'

Be it known that I, JAMES M. Lnnvnn, J r., a citizen of the-United States, residing at Oakland, in the county of Alamedal and citate of California, have invented new and useful improvements in Gear Drives, of which the following is a specification.

lhisinvention has reference to planetary gear drives mounted coaxially with oscillatory swinging frames, and is designedv for transmitting rotary motion from a source of power to a driven element, with the rate of transmission accelerated.

For convenience of description, it will be considered that the transmission of power is to a rotary tool by way of inter-meshing gears proportioned to give the desired ratio,

such gears replacing'belt drives heretofore customarily used for a like purpose, and thereby entirely avoiding slippage, which is liable to occur in short belt drives and, furthermore, eliminating` the necessity of belt tightening devices. The gear drive is further admntageous over a belt drive, in that the machine may be of simpler construction, much more compact, and is preferably direct motor driven, thus savingspace and giving positive working results. rlhe invention in its preferred embodiment is applicable to machines in which the tool is ro tated and is arcuately aised or advanced to and through the work, or is swung about an axis located above the work and presented to and through the work by a rocking movement about the axis of suspension.

The invention is adaptable particularly to driving a rotary saw, while not necessarily limited to such particular use, and when so employed such saw is efficiently used as a rotary cut-off saw for accurately severing lumber, with aminimum travel of the saw, the lumber remaining stationary during the cut offoperation and the. saw traversing to and through the lumber in an arcute path. The invention also embraces improvements inthe counterweighting of oscillatory swinging frames and their appurtenances, in machinos for sawing wood, inasmuch as the distribution of counterweight appertaining thereto maintains such frames in substantially stable equilibrium when occupying the initial starting position, and insures the return of the swinging frame to their original position, at one end of the oscillatory swinging stroke, from any other position. This distribution of counterweight also Serial No. 432,988.

serves variously to oppose the downward and assist the upward movements of the swinging frames by reason of shifting'- of the center of gravity of the counteiweight during the backward and forward swing-ing of the frame. The counterweight is distributed in such modified degree as to insure easy and rapid oscillation of the swinging frames by the operator.

The invention will be best' understoodk from consideration of the following detailed description taken in connection with the accompanying drawings formingpart of this specification, with the understand ing, however, that the invention is not coniined to any strict conformity with the showing in the drawings, but may be changed and modified so long as such changes and modi- {ic-ations mark no material departure from the salient features of the invention asexpressed in the appended claims.

ln the drawings:

Figure l is a side elevation of a machine embodying the invention, showing the saw in the initial or inactive position, ready to be lifted to the work through a. rising arc.

Fig. 2 is a vertical section in a` plane at right angles to the showing of Fig. l, but with the saw raised to the upper limit of its travel, and having independent mountings for both the rotary saw frame and the drive shaft.

Fig. 3 is an elevation of a type of machine embodying the invention, which may be termed the rotary or floor swing type.

Fig. 4 is an elevation of the structure of Fig. 3 as viewed from thefleft hand side thereof. i

Fig. 5 is an elevation of another type of machine embodying the invention and which, because of its structure and operation, may be termed the suspended swingl saw machine.

Fig. 6 is an elevation as seen from the left hand side of Fig.

Referring .first to the structure shown in Figures l and 2, there is shown amain frame comprising a table l mounted on a frame composed of web and flange supports 2. the gear drive of Figures l' and 2 being shown, but not c aimed, in Letters Patent No. 1,359,394 granted to meon No# vember i6, i920, for an intermittent and oscillatory rotary cutoff saw machine.

Mounted in anti-friction bearings 3a carried by brackets 3 supported by the side frames 2 is a drive shaft 4, carrying a pulley at one end, aid pulley being arranged to be driven by a belt 6 receiving power from any suitable source, the belt being in dicated in Fig. 1 by a dot and dash line. Another bearing 3b spaced 'from the bearing 3a carries a sleeve 3d. The bearings are retained in the brackets 3 by cap plates 3G. (Fig. 2).

Mounted rigidly on the sleeves 3d turning loosely on the shaft 4 without interference from the rotation of the shaft is a. rotary saw frame formed of a counterweight structure composed of two arms 7, joined together at one side of the axis of the shaft 4 by an offset connecting member 8, forming part of the counterweight. The counterweighting of the arms ,7, and the member S, is variously positioned relative to the axis ofrotation and the longitudinal axis of the structure, whereby the swinging` Jframe in its oscillation is inuenced by varying restraint due to continuous change of center of gravity of the counterweight, which al ways acts to ret-urn the frame to its original position of substantially stable equilil s rium at the predetermined position of rest, .from any other position. Un the other side of the axis of the shaft 4 the arms 'i' carry journal bearings 9 traversed by a saw arbor l0, mounting a rotary cut-otfsaw 11. The described construction is also shown in Figs. 5% and 9 of the above-mentioned patent.

The shaft 4 carries a gear wheel 12 between the arms 7, and the arbor 10 carries a gear pinion 13 between the bearings 9, the pinion and gear wheel being connected by keys 15 and 14 to their respective shafts and constantly intermeshing. In this manner, when the drive shaft 4 is rotated by means of the belt 6 the pinion 13 is correspondingly rotated, and in the particular arrangement of the drawings at a higher speed than shaft 4.

The counterweight arms 'T with the saw or tool 11, are capable of rocking on the sleeves 3b about the longitudinal axis of the shaft 4 so that the saw 11 may be dropped below the level of the table 1, as shown in full lines in Figure 1, or raised above the level of the top of the table 1 as indicated in dotted lines in Figure 1 and shown in -tull lines in Figure 2, the extentv of raising being sufficient to carry the cutting edge of the saw in an upward arc through the thickness and width of the material to he cut.

In order to move the saw arcuately for feeding purposes, the counterweight frame comprising the arms? and connecting member S, has drums 16 fast thereto, these drums being preferably in the form of sprocket wheels, and engaging these sprocket wheels are sprocket chains 17 dropping` tol other sprocket wheels 18 with which they engage. in Fig. 2 the sprocket wheels 16 are either shrunk on or held by the set screws to the `sleeves 3d, which are rigid with the arms 7,

said sleeves turning free of contact with the shaft rfhe sprocket wheels 18 are mount ed on ay countershaft 19, carried by the frame members 2, near the lower end of the frame, and adjacent to the shaft 19 is another shaft 2O journalled in the frame members 2 and connected to the shaft 19 by means of a pinion 21 on the sha-ft 19 and a gear segment 22 on the shaft` 20. Fast to the shaft 2O is a treadle member 23 provided with a treadle 24 in position to be readily engaged by the foot of a workman, so that on depressing the treadle the gear segment 22 and pinion 21 are actuated in the appropriate direction to wind the chains 17 to rock the counterweight structure '7, 8 and thereby raise the saw above the table 1. From the foregoing it will be noted that the weight of the rotary saw frame or yoke frame coinposed of parts T, 8, 9, 10, together with the sleeves 3d and the bearings 3b is sustained by the main frame. The drive shaft and its mountings is coaxial with the yoke traine, but free from contact therewith and carryu ing no other weight than its own. The ball bearings 3^ support the weight of the power or drive shaft, while the bearings 3l main-- tain the weight of the sleeves 3d, the sprocket 1G and the yoke frame.

The table 1 is provided with the usual straight edge or abutment 25 for the work and there is also provided a shield or guard 26 into which the saw 11 moves when retracted from engaging relation with the work.

The machine shown in Figures 1 and 2 and also shown in the aforesaid Letters Patent, but whose gear drive is not there claimed specifically, because it is provided with a gear drive instead of a belt drive, has material advantages over the other ina chines shown and described in the aforesaid Letters Patent. rllhe employment of gearing instead of belting greatly compacts the drive and eliminates any necessity of heli; tightening devices, and avoids putting the elements of the drive under side strains ou the bearings, with consequent wear. The driving mechanism con'iprises a minimum of parts, consisting in Figs. 1 and 2 of two gears, a drive shaft and a drive pulley. The irregular distribution of counterweight relative to the rotary frame of this machine is likewise materially advantageous inasmuch as it provides easy and rapid oscillation of the rotary frame with the least amount of exertion on the part of the operator.

In Figures 3 and 4, there is shown what may be termed a rotary or floor swing saw of somewhat different design from the ma` chine shown in Figures 1 and 2, and employing an electric motor as the drivingI means instead of a. belt. Furthermore, the

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machine of Figures 3 and Si provides anintermediate gear between the power shaft and the saw arbor, which intermediate gear may be made of raw hide or other nonmetallic material. thereby lmaterially reducing noise.

In Figures 8 and 4, the main frame includes a table la and side members or legs 2, being in this respect generally similar to the showing of Figures 1 `and iv, Fast to one of the members 2a of the main frame is a bracket 27, upon which is mounted an electric motor 28 supplying the motive force for the machine, so that the machine as a Whole is self contained and does not need extraneous driving mechanism.

Fast to the armature, of the motor means of a suitable coupling 29 is a shaft 30, corresponding to the drive shaft 4 of the machine of Figures l and 2. This shaft 30 is mounted in suitable journal bearings 3l carried by the f'ame members 2, and mounted on the shaft 30 to rock thereon Without participation in its rotative move` ments are counteriveight arms-TLL corresponding to the counterweight arms 7, but of greater length. The bearings 3l and the mounting of the power shaft BO and arms Ta correspond with the construction shown in Fig. 2, the intention being that the counterweighted rotary saw frame shall be free from contact with the power shaft 30. rllhe arms 7a at one side of the shaft 30 are joined by an offset connection Sa, contributing to the connterweight eifect, and on the other side of the shaft 30 the arms 7a carry tivo sets of journal bearings 9, 9b spaced apart in the direction of the length of the arms 7a. The bearings 9a carry a countershaft l()a and the bearings 9b carry a countershaft 10b. Fast to the shaft 30, between the arms 7, is a gear Wheel l2a and carried by the shaft l()a is an idler gear l2, While fast to the. shaft l0b is a pinion 12C, the gears 'l2 all intermeshing and the idler gear 12b being preferably formed of ran' hide or other fibrous material for reducing or eliminating noise.

The shaft 101 carries a saw lla, and on the operators side of the machine, in position to receive the san' ll, is a shield or housing' 26a. In the structure shown in Figures 3 and 4, the sanv .may be always exposed above the table l, instead of dropping be lou* the table when not in action, as in 1the struct-ure of Figures l and Q. The height of the machine may be the same as in the structure ofFigures l and 2 and the inclusion of the idler or intermediate gear l2 doe-s not occupy any more space.

Journa-led in the lower part of the frame 2, is a rock shaft 82 extending across the machine and carrying levers 33 keyed or otherwise made fast thereto, so as to move together. These levers are connected by 28 by power sprocket chains 18 to sprocket wheels or drums 16a fast to the arms 7 for causing swinging of the saw at the will ot' an operator. For this purpose one of the rock arms 33 extends to an accessible position at the operator-s side of the machine and maybe there provided with a treadle 24,

Because the saw is constantly exposed above the top of the table la, the countern'eight yoke should be under a normal constraint to more away from the operator, Which constraint is preferably accomplished through the medium of an irregularly distributed counterweight, which insures stable equilibrium at the nedetermined starting position or position of rest. Auxiliary to the counter-Weighting of the oscillatory swinging yoke frame is a rod 3lconnected at one end to one of the arms i and at the other end traversing a rock bar 235 supported by the main frame. Surrounding the rod 3 is a spring 3h abutting at one end the rock bar 35 and at other end abutting adjusting nuts 3T on the rod Si, While other adjusting' nuts 38 are carried by the rod Set where it projects beyond the har 35. In this manner, the tension of the spring may be adjusted to suit conditions.

iii/*hen it is desired to feed the san' tool lln to the Work` Y the operator bears upon the 'treadle 2st, thus actuating the sprocket chain or chains 1Sa and causing the tool ll to move from its retracted position shown in dotted lines in Figure t to the advance position shown in full lines against the normal restraint produced by the changing center of gravity of the counteru'eighting of the oscillatory frame and action of the spring 3G. On releasing pressure on the treadie 2li? the counterweight eii'ect and the spring returns the parts to their iirst position. The purpose of the springl En is primarily to add resiliency and to assist the counterweight in quicxly returning the yoke frame to or tmvards its position of rest, so that the operator may oscillate the yoke fra le rapidly and have the minimum of inertia to contend with at the extreme Working end of the stroke. Adjustment of the abutting nuts 3T and 38 on the rod 3ldeterniines the tension of the spring IHS.. and correspondingly the speed of return and stroke of the yoke frame. Figures $3 and 'si provided with a straight edge or abutment 25, like the machine of Figures l and 2.

In the structure shown in Figures 5 and 6, the machine in the main is like that shiwvn in Figures 3 and it being a three-gear machine, but differs therefrom in that the tool carrying arrangement oi" the suspended swing type and consefpieu ly is a higher ma chine than either of the other two. there l with posts or stand.-

r ards i0 rising therefrom above a table -i-l,

is provided a frame 23;,

The machine oi" having rollers 4t2 journaled therein, to support the work and permit it to be moved easily there along with one long edge against an edge or abutment 25h.

At the upper end of the posts 4l) there is secured a timber l2` Secured to the tiniber 4t2 are spaced journal bearings 13 in which is mounted a drive shaft elet AXtendm ing horizontally, that is, parallel with the table el. Also carried by the timber 42 is an electric motor l5 connected to the shaft ist by a coupling lil or otherwise.

Mounted upon the shaft Llll to rock thereon is a yoke frame 43.7 haring depending legs l5 connected at the lower ends by a Ivoke connection t? provided with a handle 50 for convenience in manipulation and within reach of an operator so that the lframe 48 with parts carried thereby .may be inoved by the operator across work on the table i-l. ylhe construction of the bearings i3 and the mounting of the yoke frame all' and the power shaft Ll-1t are similar to the corresponding parts shown in 2, and i'or the same reasons.

Fast to the shaft 41k is a gear wheel 5l like the gear wheel l2a of the structure of Figures 3 and Ll, the gear wheel 5l meshing with an idler gear on a countcrshaft 53 having journal bearings 54 in the `yoke ehi interino diately of the length thereof. the gear wheel 52 being preferably formed of fiber or fibrous material to reduce or eliminate noise. At the lower ends of the legs of the yoke e8 are journal bearings 55 for a shaft or arbor 5G carrying at one end a saw or other tool 5T and at an intermediate point a pinion 58, meshing with the gear 52 and receiving power therefrom.

Fast on the timber e2 is a bracket 59 to which is connected one end of a toggle lever 60, having its other end 6l connected to a bracket 62 intermediate of the width of the yoke 47.- The member of the toggle connected to the bracket 59 carries a weight 63 held thereon by a set screw Gil, so that its position along the toggle member may be adjusted.

When the frame 48 is in the full line posh tion shown in Figure 5, that is, before the saw enters the work, the toggle 60 is nearly straightened with the weight 63 active to hold the saw away from the work. 1V'Vhen the operator grasps the handle 50, and pulls the saw toward him, the saw is made to enter and traverse the work, rocking about an axis coinciding with the axis of the shaft 44C. The toggle or link structure 6() breaks at an intermediate point, as shown in dotted lines in Fig. 5, thereby raising the weight ($3 to a location in which the Weight tends to return the parts to their first-l. position.

In all three types of machines which have been described, there is a cooperation between the driving means for rotating the saw and the swinging and restraining of the frame which carries the saw. The saw as shown for example in Fig. l will, owing to the gear leverage, feed itself into the lumber kand through the cut, once it has entered the cut, without assistance. The counterbalance of the frame not only functions as a counterbalance, but also offsets the tendone)7 of the swinging frame to rotate with the drive gear. If the swinging frame were perfectly balanced, and the frame was free to revolve, the instant t-he power was applied the frame as well as the saw would start to rotate, and the frame would accelerate until it reached a high speed. If the frame were not properly counterbalanced, the machine would be useless because the saw would dig into the work (or pull away from it, according to the direction of the gear rotation) and its movement could not be controlled.

The operation of my gear drive machine is such that if the machine were started and the cutting edge of the saw held, the rotary,r motion would be imparted wholly to the swinging frame. Either the frame must move or the saw must inove. By driving the saw in the direction indicated in the drawings, l make the rotary pull ou the swinging frame assist in swinging the traine int-o and through the cut. action of the saw is accelerated as the swinging frame advances to the work.

That is claimed 1- 1. ln a machine of the character described the combination with a main fram@ of a rockable -fraine pivot-ally mounted therein and having a rotary tool and its shaft mounted thereon, of a train of int rineshing power transmitting gears cool-di natcly mounted and operable relative to the axis of rotation of the rockable frame. a rotatable power shaft mounted coaxial wiiii the axis of rotation of the rockzble frame, one of the gears being mounted on the poire; shaft and another gear on the tool shaft. means for imparting to the rockahle frame a normal constraint to rock in one direction7 -and means whereby said traine may be rocked in the opposite'direction against its normal constraint.

2. In a machine of the character described7 a saw7 a pivoted saw frame cai ing the saw and saw arbor movable on its axis in an arc toward and from the work.y a train of interineshing power tra nffuniitting gears coordinatel)vv mounted and operable relative to the pivoting of the saw frame` a rotatable power shaft mounted co^"al with the axis of rocking of the sa w ir me. with the train of gears between the power shaft and the saw, one of the gears being mounted on the power shalt and another gear on the saw arbor, and means constraining the rockable saw frame toward one limit of its movement and yieldable to the Furthermore. the .'f

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movement of the frame in the opposite direction.

3. .ln a machine of the character described, the combination with a support having bearings, of a rockable frame pivotally mounted in Said bearings, whereby the weight of said frame is sustained by said support, movable toward and from the work, a rotatable power shaft independently mounted in bearings of said support, c'oaxially with the axis of rotation of the rockable frame, so that it is free from contact with the rockable frame, a saw arbor and saw also carried by said frame and participating in its movements toward and from the work, a train of intermcshing power transmitting gears between the power shaft and the saw arbor, one of the gears being mounted on the power shaft and another gear on the saw arbor, means constraining' said frame to rock away from the work and yieldable to forces tending to rock it toward the work, and operator-controlled and actuated means for rocking said frame toward the work.

el.. In a machine of the character described, the combination with a support having bearings, ofv a rotatable power shaft, a frame pivotally mounted in the bearings of said support, the axis of rotation of said frame and said shaft being coaxial, a saw arbor with its saw carried by the frame at one side of the longitudinal axis of the power shaft and rockable with the frame, counterweight means on the frame at the other side of said asis tending to assist to move the saw arbor and saw bodily in one direction, resilient means coacting with the counterweight means to return the rockable frame to normal position, operator-controlled means for rocking the frame toward the work, and a train of internieshing power transmitting gears connecting the power shaft and the saw arbor, whereby the driving power for the saw is directly transmitted without slip to the saw arbor, and the counterweight means offsets the tendency of the rockable frame to yield too freely to the feed of the saw into the work.

In a machine of the character described, the combination with a support, of a rotatable power shaft, a counterweighted frame mounted on the support to rock about the longitudinal axis of the power shaft without interference from the rotation of the shaft, a saw arbor and saw carried by the counterweighted frame in spaced relation to the power shaft, and intermeshing power transmitting gears carried by and movable with the frame for positively co-nnecting the power shaft and saw arbor together at all times to drive the saw arbor at a constant speed from the power shaft irrespective of the position of the frame, the driven gear being rotatable about the drive gear While both gears are in motion, the

counterweight on the frame offsetting the tendency of the frame to yield too freely to the feed of the saw into the wort'.

6. lu a machine ofthe character described, a main machine frame, a yoke-shaped counterweighted saw carrying frame rockably mounted on the main frame and comprising a pair of arms joined at one side of the axis of the carrying frame by an offset connectingr)` member forming part of the counterweight, a saw arbor carried by the rockable frame and joining said arms at the opposite side of the axis, a saw on said arbor, a rotatable power shaft mounted coaxial with the longitudinal axis of the rochable frame so that its rotation is free of the rockable frame, and a train of gears between the power shaft and the saw arbor and connecting the same and constituting positive power transmitting means between the power shaft and the saw arbor,` the counterweight offsetting the tendency of the saw carrying frame to yield too freely to the feed of the saw into the work.

7. In a machine of the character described, a counter-weighted rockable frame with spaced side arms, shafts journaled in the side arms, one of the shafts constituting a power shaft and rotatable freely and independently of the side arms and located at the axis of movement of the frame, another shaft constituting a support for a driven element movable with the frame, and intermeshing gears connecting the power shaft and the second mentioned shaft and located on the two shafts between the side arms, the driven gear being rotatable about the drive gear while both `gears are in motion.

In a machine of the character described, a support, a rockable frame pivotally mounted on said support, a rotatable driving element mounted coaxial with the axis of rotation of the rockable frame, a driven element mounted on the rockable frame and rockable about the driving element with the axis of the driven element at all times equidistant from the driving element, and intermeshing gearingl connecting the driving element and the driven element and constituting the ine-ans of transmitting power between the driving and the driven elements.

9. In a machine of thev character described, the combination with a saw, of a saw frame movable toward `and from the work, a rotatable power shaft about which the saw frame is mounted to rock freely and independently of the rotation of the shaft, a counterweight at one end of the saw frame` the saw being mounted at the other end of the frame, a resilient means coacting with the counterweight to impart a normal constraint to the saw frame to move away from the work, and a train of intern'ieshing power transmitting and speed increasing llO gears movable with the trame, the drive gear being mounted on the power shaft and the driven gear on the saw slrat't, the driven gear being rotatable about the drive gear while both gears are in motion, whereby the rotary pull on the saw trame assists in swinging said trame through the cnt in the lumber.

l0. In a machine of the character cle-- scribed, the combination with a saw, of a saw frame movable toward and from the work, a rotatable power shaft about which the saw frame is mounted to rock vtreely and independently oi' the rotation ot said shaft, a` train of intermeshing power transmitting `and speed increasing gears for the saw movable with the traine, one ot the gears being mounted on and driven by thc power shaft, means for imparting to the frame a normal constraint to rock in one direction, and manually operated means whereby the frame may be rocked. in the opposite direction against its normal constraint, the action of the saw being accelerated as the saw trame advances to its work, whereby the saw will assist in feeding itselt` into the lumber and through the cnt. in the lumber once it has entered the cut.

1l. In a machine of the class described, the combination with a support, of a rot-ary cutter carrying frame pivotally mounted on said support, a rotary cutter and its shaft mounted on the carrying trame, a rotatable power shaft mounted coaxial with the aXis of rotation ot the carry ing trame, a train of intermeshing power transmitting gears between the power shat't and the rotary cutter sha-tt, one ot the gears being mounted on the power shaft and another on the rotary cutter shaft, means constraining to rock the iframe away trom the work and yieldable to forces tending to rock it toward the work, and operator-control]ed means tor rocking the traine toward the wor l2. rIhe combination with a support, ot a swinging saw-carrying iframe on said sup port, a saw carried by said trame, means for swinging said iframe, and means associated and functioning with said .traine serv ing variously to oppose the downward and assist the upward movements ot the trame, and also serving to return the frame to its normal starting position at one end of its swinging working stroke from any other position.

In testimony that I claim the foregoing as my own, I have hereto atixed my signature JAMES MARSHALL Lniivnn, an.

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