US2484187A

US2484187A - Drive mechanism

Info

Publication number: US2484187A
Application number: US497673A
Authority: US
Inventors: Hugh W Sanford
Original assignee: SANDEBOND PATENTS Inc
Current assignee: SANDEBOND PATENTS Inc
Priority date: 1943-08-06
Filing date: 1943-08-06
Publication date: 1949-10-11
Anticipated expiration: 1966-10-11

Description

Oct. 11, 1949. H. w. SANFORD 2,484,187

DRIVE MECHANISM Fil ed Aug. 6, 1943 I v SSheets-Sheet 1 Oct. 11, 1949. w, SANFORD 2,484,187

DRIVE MECHANISM 3 Sheets-Sheet 2 Filed Aug. 6, 1943 Oct. 11, 1949.

H. w. SANFORD DRIVE MECHANISM 3 Sheets-Sheet 5 Filed Aug. 6, 1943 wmm Patented Oct. 11, 1949 UNITED STATES DRIVE MECHANISM Hugh W. Sanford, Knoxville, Tenn, assignor to Sandebond Patents, 111.10., Knoxville, Tenn, a

corporation of Delaware 16 Claims.

This invention relates to an improvement in drive mechanisms, that may be used for the operation of feeding means that supplies fuel to the combustion chamber of a furnace or other heater, such for instance, as that set forth in the application filed by Hugh W. Sanford and Alfred F. Sanford, II, Ser. No. 422,188, filed December 8, 1941, now Patent No. 2,393,710.

Many mechanisms, such as the stoker mentioned, require the operation of two plungers reciprocating in opposite directions, and it is desired that one of these move through a longer strok than the other; that the strokes of the plungers be relatively variable; that they lie in the same vertical plane; that substantially uniform velocity of travel of each plunger be provided through its entire stroke, with a constant effective pressure of each plunger throughout; and that the plungers be operated without release of pressure on both at the same time.

As shown in the above-mentioned application, these plungers were operated by a crank mechanism which has not proven to be entirely satisfactory nor to accomplish the desired results in the operation of the plungers.

The object of this invention is to improve the driving mechanism to obtain the above-mentioned effects and with a cheaper construction; where the pressure exerted by each plunger is constant throughout its stroke; wherein the two plungers may be arranged in the same vertical plane without an offset of the drive shaft that would otherwise throw sidewise stress on the mechanism, and wherein the relative stroke of the two plungers can be varied as well as the speed of uniform velocity of one plunger relative to the other.

These objects are accomplished by an intergeared connection between the plungers which will transmit the motion of a drive shaft thereto,

the gearing being such as to impart the required reciprocation of the plungers in the same or opposite directions as desired. It is preferred to utilize racks and pinions connected with respective plungers and interconnected through gearing, which may be constructed to accomplish all of the requirements for such mechanism.

A further object of the invention is to improve the reciprocating means of one plunger or other device to provide for reciprocating movement by a continuously rotating gear element. This is accomplished by the alternate engagement of said gear element with racks, but without relative lost-motion between the racks due to springs or other devices.

The gear element and the 2 racks, or at least the racks, have the teeth thereof spaced double the normal distance apart, which prevents the rack from sliding very far due to end pressure as well as preventing the gear element from getting out of mesh therewith.

A preferred embodiment of the invention, together with modifications thereof, are shown in the accompanying drawings, in which:

Fig. l is a vertical sectional view through a portion of a furnace, showing this invention applied to stoker mechanism thereof;

Fig. 2 is a diagrammatic sectional view showing gearing interconnecting means for operating the plungers;

Fig. 3 is a horizontal sectional view therethrough on the line 3-3 of Fig. 2;

Fig. 4 is a view similar to Fig. 2, showing another form of geared connection;

Fig. 5 is a vertical sectional View partly in elevation, showing the driving mechanism of Fig. 1, somewhat enlarged;

Fig. 6 is a vertical cross section therethrough on the line 66 of Fig. 5;

Fig. 7 is a vertical longitudinal section, partly in elevation, showing another form of rack and gearing for operating the plungers; and

Fig. 8 is a vertical cross section therethrough on the line 88 of Fig. '7.

The invention is shown in Fig. 1 as applied to stoker mechanism of the character set forth in the application of Hugh W. Sanford and Alfred F. Sanford, II, Ser. No. 422,188. In such a furnace, the base structure is designated generally by the numeral i, enclosing a combustion chamber 22, above a grate 3, which supports thereon a fuel bed in the combustion chamber. A heating chamber l is mounted over the combustion ch nber 2 to receive the smoke and products of ustion therefrom.

striker mechanism is mounted within the base structure i for the feeding of fuel into the combustion chamber 2 and for the discharge of ash therefrom. A fuel hopper 5 contains a supply of coal or other fuel and feeds the same downward automatically onto an under-lying shelf plate a which extends to a point adjacent one side of the combustion chamber 2 with a dawn-turned inner end E, leaving a passageway 8 through which the fuel is dumped into the combustion chamber over the grate 3. The grate structure it closes the major portion of the bottom of the combustion chamber 2 but has a base plate 9 extending horizontally therefrom under the inlet opening 8 and through a portion of the '22. nection between the housing 20 and the plunger base structure I to support the stoker mechanism thereon.

A plunger l operates over the base plate 9 substantially to the edge of the grate 3, said plunger in having a scraping edge I l at the bottom thereof and a back-turned flange I2 at the top, said flange underlying the lower edge of the inner end I of the shelf plate 6. The plunger It] is mounted on a plunger rod I3 slidably guided in a self-aligning box l4 supported upon the base plate 9.

A second plunger is shown at l5 operating over the shelf plate 6, with a shank portion it thereon for reciprocating said plunger l5.

The furnace structure as well as the plungers l0 and i5 as described above, correspond substantially with similar structure set forth in the above-'nentioned application, Ser. No. 422,188, and will function substantially in the same manner as there described. For operating these plungers in the stoker mechanism, I prefer to use the drive mechanism shown in Figs. 1, 5 and 6. This form of drive mechanism has provision for inter-connecting the plungers I0 and I5 and to reciprocate them in opposite directions.

.edgewise within a guideway formed by upstanding guide plates 2| supported upon the base plate 9. The housing 20 has a shank 22 on the inner end thereof, which is externally threaded to receive thereon adjustable jamb nuts 23. The shankZZ has an internal bore slidably receiving therein the plunger rod l3. Said plunger rod [3 carries a cross-pin 24, the ends of which are received in slots 25 formed in the threaded shank This pin and slot form a lost-motion conrod l3, for reciprocating the plunger rod and the plunger I!) connected therewith. The length of -29 enclosed within the slotted opening 26. The

teeth 2'! and 28 are spaced double the normal distances; apart for a purpose hereinafter described, and the teeth of the pinion member 29 are similarly spaced. The teeth of the pinion member 29 extend through an arc or segment such that they will inter-engage the teeth of one or the other of the racks 21, 28, at all times.

The pinion member 29 is mounted on a drive :shaft 30 operated by a motor 3| supported on the base plate 9, as shown in Fig. 1.

The upper edge of the housing 20 is formed 'with a guideway 32 therein slidably receiving a rack 33. abutment 34 at one end of the guideway 32 and "a screw 35 threaded through a flange portion 36 The rack'33 is interposed between an on the housing 20, said screw 35 being provided with a lock nut 31 on the outer side of said flange 36.

A gear member 38 is journaled on a pin 39 suspended by brackets 40 from the shelf plate 6, for 1 rotation within a slot 4| in said shelf plate. The gear member 33 is provided with two segments of ear teeth 42 and 43 at different radii and on oppositely spaced portions thereof, the teeth 42 being in position to mesh with the teeth of the rack 33, while the teeth 13 are in position to mesh with a rack 44 secured to the shank portion E6 of the plunger 55, as shown in Fig. 1. The: rack M is held in mesh with the teeth 53 by a hold-down roller 55 bearing upon the upper edge of the rack M, and journaled on a pin Q5 mounted in brackets 47 supported upon the shelf plate 6.

In operation, it will be evident that the motor 3! will rotate the drive shaft 35 continuously in one direction, while imparting reciprocating movements to the plungers Ill and 55, in opposite directions from each other, and through relatively different strokes. The rotation of the drive shaft 35 will turn the pinion member 2% in the direction indicated by the arrow in Fig. 5, thus reciprocating the housing 20 in the guideway 2|. This reciprocation will-move the plunger rod [3 through the lost-mcticn connection 24, 25 to reciprocate the plunger If], and at the same time, 'will oscillate the mutilated gear member 38 to reciprocate the rack 44 and plunger 55 connected therewith. This mechanism has been tested in every possible way and found to be extremely practical and to accomplish all of the desired results therefor.

At the same time, it was found that the teeth of the gearing do not lock regardless of the endwise pressure that maybe imparted to the housing 25 in either direction or at any time in the stroke. The close clearance between the hub of thepinion member 25 and the end wall of the opening 26 at each end of the stroke, as indicated respectively in full lines and in dotted lines in Fig. 5, aids appreciably in limiting the free movement of the housing. fAs shown in Fig. 5, when the tooth 29a leaves the adjacent tooth 21a, a presssure on the housing 28 toward the right would move the housing only very slightly before it engages the hub of the pinion member 29 due to the small clearance allowed therebetween. However, it is impossible for the housing 20 to be moved toward the left at this point to prevent the tooth 295 from engagingbetween the teeth 28a and 28b.

The elimination of every other tooth of the rack and pinion, or at least of the rack, provides a rack motion without relative movement between the racks due to springs or other devices, wherein the pinion tooth 290. not only would be free to leave the rack, tooth 2101 before the pinion tooth 29b engages the rack tooth 28a, but prior to this the tooth 29b is located below the top of the teeth 25, 28a, a condition which prevents the rack from sliding very far to the left under pressure, and which prevents the gear from getting out of mesh due to end pressure in either direction at the, time when the tooth 29a leaves the tooth Z'la.

Thus it is impossible for the teeth to get out of mesh or to have one tooth engage directly on the end of another, even though the tooth 29a should leave the tooth 2M slightly before the lower tooth 29b strikes the tooth 2811. This is accomplished by eliminating every other tooth at least of the rack, but preferably of both the rack and the pinion.

The maximum stroke of the main plunger l!) is limited to the distance between the end teeth on the driving pinion member 29, as this rotates from the full-line position in Fig. 5 to the dottedline position therein, but this stroke can be increased by using a larger mechanism and a driving pinion member of larger diameter. The relative relative to the stroke of the main plunger maximum stroke of the feeding plunger l5 depends upon the respective radii of the mutilated gear member 38. By moving the location of the mounting pin 39 closer to the housing 2 it would On the other hand, by raising the mounting pi 39 closer to the rack 4- 5, this relation would be reversed.

Provision is made also for controlling independently the stroke of each plunger by adjustable lost-motion means. Thus, by adjusting the jarnb nuts '23 lengthwise of the slot 22, the stroke of the 2 2 may be varied, thereby adjusting the lost-motion between the housing 28 and the plunger rod I3. If the jamb nuts 23 are moved up against the pin 24 in the relation shown in Fig. 5, all lost-notion would be eliminated.

Although the stroke of the feeding plunger i5 could be controlled in a manner similar to that provided for the main plunger 59, another form of control therefor is shown in Fig. 5. This is provided by the screw 35 threaded through the flange 36. When this screw is turned counterclockwise, it would increase the space between the left-hand end of the screw and the slidable rack 33, thus allowing the rack to slide to the right to the amount of clearance provided between it and the left-hand end of the screw 35, relative to the housing 20. The housing may, therefore, move through this distance before there would he movement of mutilated gear member 36 and of the rack 44.

In the stoker mechanism to which this invention is shown applied, a simple adjustment of the jamb nut 31 and the screw 35, is sufficient to vary the stroke and thereby the feed of the upper feeding plunger I5 to provide for the proper desired amount of feed of fuel to the furnace.

A modified form of drive mechanism is shown in Figs. '7 and 8 for reciprocating the main and feeding plungers lila and lda. In this form, the housing 50 connected with the plunger lfia is slidably mounted on the base plate 911, and encloses within the confines thereof a driving pinion 5| mounted on a motor shaft 52 which operates the same. The pinion 5! has segmental teeth. in position to mesh alternately with upper lower racks 53 and 54. The racks 53 and 5d are slidahly mounted in guideways 55 respectively, in the housing 50, while being confined therein by retaining screws 51 which engage in grooves in the respective racks. One end of rack 53, 54, abuts against the housing 553, while the opposite end thereof has a spring 59 or @353, respectively interposed between said rack and the housing.

The housing 50 carries a rack 6i bearing one end against a screw 62, corresponding substantially with the rack 33 and screw described above. The rack 6! meshes with segmental teeth on a mutilated gear member 54, while segmental teeth 55 on said gear member meshes with. rack it connected with the feeding plunger is to operate the latter. These parts being similar to those referred to above in connection with Figs. 5 and 6, will function in the same as described in connection therewith.

In the operation of this form of the invention, the rotation of the pinion 55 by the drive shaft 52 of the motor, as indicated by the arrow in Fig. 7, will cause reciprocating movement of the housing 55. The lower end tooth or the driving pinion 5| engages the teeth of the rack 54 just 6 after disengagement by the uppermost end tooth thereof from the rack 53. However, just before the disengagement from the rack 53, the spring 59 is uncompressed until after the engagement and movement of the rack 54. Then, when the tooth of the driving pinion 5i engages and moves the rack 54!, just before the rack '53 has been disengaged by the uppermost tooth of the pinion, the rack 54 will move endwise and compress the spring El-l. This movement can be varied by changing the design ofthe spring and clearance between the-parts.

During this instant, the racks 53 and 54 are movin simultaneously, but due to the spring connections between these racks and the housing 59, there will be no shearing of the pinion teeth,

or other interference with the operation, and yet there will be no period of time when the pinion is not engaged with one or the other of the racks for positive operation of the housing and of the plungers connected therewith.

In lieu of mittin.g motion between the housing and the rack of the feeding plunger through a mutilated gear as shown at 3 8 or which will cause reciprocating movement of the main and feeding plungers in opposite directions, these plungers may be operated in opposite directions at variable ratios, through gearing as illustrated Figs. 2 and 3. This device would work regardless of the length of stroke of the lower rack, such as is designated 33a corresponding, for instance, with the rack 33 in Fig. 5, while the upper rack is designated in Fig. 2 as Mia, to move the feeding plunger.

These racks and lia are interconnected by series three gears, designated generally by the numeral iii and journaled on shafts'll. These shafts lll are mounted in vertical guideways or slots in which they fit loosely so that the gears '55 bear upon each other'in superposed relation as shown in Fig. 2. In order to change the ratio of travel of the racks 33a and Ma relative to each it necessary merely to take out the gears from the guides and to substitute new pone with different ratios of teeth, so as to change the relative speed ratios in. any referred way.

On the other hand this type of connection may he subs 1 uuted for the mutilated gear 33 or while ob .ing different relative ratios of travel the direction of the reciprocating plungers, as shown Fig. l. Here, two gears are shown at 8 ntermeshing with each other and with rack sac and d ll), the gears as being mounted on shafts 3i sliclably mounted in verticallv arranged guideways 32 similar to the guide'ways t2 s own in F 2 and 3. The ratios of these racks no he varied by removing the others or reversing their .procating plungers vertically spaced relation,

acted ring, pered and operated y may be moved ent strokes, with uni- .it i travel through the entire and with a substantially constant pressu These characteristics are particularly desirable in a stoker of ti e character referred to, although. this ve mechanism may be used wherever the desired functions thereof are found useful.

While it by racks arr operat I 53 be operated as the driving pinion of. he mechanism upon it rotation directly from the motor, it will be evident that this mechanism could be used in reverse whereby the reciprocating movement of the racks would impart continuous rotation to the pinionthat is inter-geared therewith without any danger of the teeth getting jammed.

.Thus the pinion 29 or would be the driven pinion, and the racks 21--28' or 5354 would be operated positively by a cross head motion connected with the associated housing. The racks would then impart continuous rotation to the pinion at a uniform velocity throughout the stroke which is not possible with an ordinary crank motion. It will be evident that one of the racks would impart movement to the pinion through one-half of the revolution of the pinion and the other rack, through the other half of its revolution, thus applying continuous rotation to the pinion.

I claim:

1. In drive mechanism, the combination of a reciprocatory support, a rotary mutilated pinion having teeth, racks carried by the support and secured thereto and arranged on opposite sides of the mutilated pinion and having teeth to engage the teeth of the pinion, means for driving said pinion to impart reciprocating movement therefrom to the racks and respectively to the support, plunger members, one of said plunger members being connected with the support and movable thereby, means for varying the movement of one of the plunger members relative to the other, and gearing having operative connection with said support and another of said plunger members for moving the last-mentioned plunger member by movement of said support.

2. In drive mechanism, the combination of a reciprocatory support, a rotary mutilated pinion having teeth, racks carried by the support and secured thereto and arranged on opposite sides of the mutilated pinion and having teeth to engage the teeth of the pinion, plunger members, means connecting one of the plunger members with the support for movement thereby, gearing connecting the support with another of said plunger members for movement by said support, and adjustable means for providing lostmotion between said support and at least one of said connected plunger members to vary the relative positions of the plunger members.

3. In drive mechanism, the combination of a reciprocatory support, a rotary mutilated pinion having teeth, racks carried by the support and arran ed on opposite sides of the mutilated pinion and having teeth to engage the teeth of the pinion, plunger members, means connecting one 7 of the plunger members with the support for movement thereby, gearing connecting the support with another of said plunger members for movement by said support, adjustable means for providing lost-motion between said support and at least one of said connected plunger members to vary the relative positions of the plunger members, and driving means connected with said pinion for rotating the pinion in one direction for imparting reciprocating movement to the support.

4. In drive mechanism, the combination of a reciprocatory support, a rotary mutilated pinion having teeth, racks carried by the support and arranged on opposite sides of the mutilated pinion and having teeth to engage the teeth of the pinion, means for driving said pinion to impart reciprocating movement therefrom to the racks and respectively to the support, plunger mem- V 8 bers,one of said plunger members being connected with the support and movable thereby, the other plunger member having a'rack connected therewith, gearing in mesh with the lastmentioned rack, and a rack connected with the support and having driving relation with said gearing for operating said gearing from the support.

5. In stoker drive mechanism,'the combination of a pair of plungers, means mounting said plungers for reciprocating movement substantially in parallel directions, a housing connected with one of the plungers, means mounting said housing for sliding movement, racks arranged in opposed directions on opposite sides of said housing, a mutilated pinion having teeth arranged to mesh alternately with said racks upon rotation of the pinion, a rotary gear member; and racks on opposite sides of said gear member and having operative driving relation therewith, one of the last-mentioned racks being connected with the housing and the other of said racks being connected with the other of the plungers 6. In Stoker drive mechanism, the combination of a pair of plungers, means mounting said plungers for reciprocating movement substantially in parallel directions, a housing connected with one of the plungers, means mounting said housing for sliding movement, racks arranged in opposed directions on opposite sides of said housing, a mutilated pinion having teeth arranged to mesh alternately with said racks upon rotation of the pinion, a rotary gear member, racks on opposite sides of said gear member and having operative driving relation therewith, one of the last-mentioned racks being connected with the housing and the other of said racks being-connected with the other of the plungers, driving means connected with the pinion for rotating said pinion to reciprocate the housing, and adjustable means for providing lost-motion between said housing and at least one of the plungers to vary the relative positions of the plungers.

'7. A drive mechanism comprising a frame structure having opposed rack gearings, a mutilated pinion adapted for continuous movement in one direction and mounted within the frame structure between the rack gearings, said pinion being arranged in position to engage each of the rack gearings during approximately one-half its cycle of rotation and being free from engagement with one rack while engaged withthe other,

'means mounting said structure for reciprocating movement in response to the engagement of said rotating pinion, a rack secured to the frame structure and disposed externally thereof for reciprocating movement with the frame structure, a plunger member operatively connected with said rack for movement thereby in response to the reciprocating movement of the frame structure, and a second plunger member connected with the frame structure for movement thereby.

8. In a drive mechanism, the combination of a frame structure mounted for reciprocating motion and having spaced apartopposed members provided with internal and substantially rectilinear rack gearing, said rack gearing having the teeth thereof spaced apart an abnormal distance greater than the thickness of the teeth along the pitch line, a mutilated pinion mounted between said members and adapted for rotation continuously in one direction, said pinion having teeth in position to mesh with the teeth of the rack gearings and to disengage alternately from one of the rack gearings and engage with the other of said rack gearings, said pinion teeth being so arranged that no two of its teeth engage with two teeth of the opposed rack gearings simultaneously, and at leastone tooth of said pinion at all times'being located between two teeth of one of saidvracks, whereby no endwise external pressure which is applied to the frame structure clu g any; t of the cycle of rotation of the pa on will cause the pi" to be out of mesh with one 01 the rack gearings and permit the frame structure to be moved u'eciably endwise by said external pressure relative to the axis of rotation of the pinion wherebteeth of the pinion and one of the rack geallngs may become jammed, or whereby the relation of the teeth of the pinion to the teeth or the rack gearing can be changed, the rotation of the pinion causing the frame structure to, reciprocate back and forth in one cycle for each complete rotation of said pinion, a plunger member connected with the frame structurr for reciprocation thereby, and adjustable regulating means for varying the extent of reci rocation of said plunger relative to the reciprocating movement of the frame structure.

9. In a drive mechanism, the combination of a frame tructure mounteo for reo1procating motion and having spaced opposed members provided with internal and substantially rectilinear rack gearing, said rack gearin':- g teeth thereol spaced apart an abnormal parlance greater than the thickness of the teeth along t -e pitch line, a mutilated pinion mounted between said members and adapted-for rotation continuously in one direction, said pinion having teeth in position to mesh with the teeth of "the rack gearing and to disengage alternatelyf none of the rack gearings and engage with other of racks said pinion teeth being so arranged that no two of its teeth, engage with two teeth of the opposes rack gearings simultaneously, and at least one tooth of said pl :1 at all times being located betwe n two, teeth of one of said racks, whereby no endwise external pres-- sure which is applied to the frame structure do ing any part of the cycle of rotation of the pinion will cause the pinion to be out of mesh with one of the rack gearings and permit the frame structure to be moved appreciably endwise by said external pressure relative to the axis of rotation of he pinion or whereby the teeth of the pinion andone of the rack gearings may become iainn ed, or whereby the relation of the teeth of the pinion to the teeth of the rack be changes the "otation of the p .1 ion ca the frame structure to reciprocate back and forth in one cycle ioreach complete rotation of said pinion, an external rectilinear rack secured to the iramestructure, and a second pinion externally of the frame structure and mounted in position to meshwith said external rack whereby the reciprocation of the frame structure causing movement of the external rack will cause rotation of, the external pinion first in one direction and then in the opposite direction during each complete cycle of movement of the frame structure. I

10. In a drive mechanism, the combination of a fram structure mounted for reciprocating motion and having spaced apart opposed members provided with internal and substantially rectilinear rack gearing; said rack gearing having the teeth thereof spaced apart an abnormal distance greater than the thickness of the teeth along the pitch line, a mutilated pinion mounted etween said members and adapted for rota with two teeth of the opposed racl: gearings simultaneoul at least tooth of said being locate-cl between two racks, whereby no endwise which is applied to the frame any part of the cycle of rotawill cause the pinion to be he of the rack gearings and rncture to be moved appreci external pressure relative on of the pinion or whereby pinion all in teeth of one externrl p struoti tion 01 ch the teet or {1116 1111 on and one of the rack gearings become jamm d, or whereby the relation or the teeth of thpinion to the teeth of the rack be changed, the rotation of the pinion causLng the frame structure to rec nrocate and forth one cycle for each complete rotation of said pinion, an external rectiln rack secured to the frame structure, and a second 1. 'on externally of the frame ed in position to mesh with nal rack whereby the reciprocation of the direc... ,n of movement of the first-mentioned plunger member and simultaneously therewith. the combination of a e for reciprocating motion and having spaced apart opposed members provid with tantially rectilinear raclr said rack gearing having the teeth thereof spac d apart an abnormal distance greater than the thickness of the teeth along the pitch line, a mutilated pinion mounted between said members d adapted for rotation continuously in c etion, said pinion having teeth in position mesh with the teeth of the rack gearing to disengage alternately from one of the rack ge and or age with the other of said rack 5, said n on teeth being so arranged t" no two of teeth engage with two teeth of op ed. rack gearings simultaneously, and at least one tooth of said pinion at all times being located between two teeth of one of said racks, whe eby no c :terna1 pressure which ructllre during any par; of the ey J on of the pinion will cause the n on to i mesh with one of the racll the frame structure to be n oved apnrecl ly endwise by said external asure relative tthe axis of rotation of the or the teeth of the pinion and o rack gee age may become jain'tn a on bile teeth of the pi in to the tee of t e ack gearing can 11 hereuprbcau n of the frame structure causing movement of' the external rack will cause rotation of'the external pinion first in one direction and then in the opposite direction during each complete cycle of movement of the frame structure, means mounting said external rack on the frame structure for relative sliding movement therebetween, and adjustable regulating means for limiting the extent of relative movement between the frame structure and external rack, whereby the frame structure may slide freely through a predetermined distance relative to the external rack without causing movement of the external rack and the external pinion during said lost-motion between the frame structure and rack.

12. In a drive mechanism, the combination of a substantially rectangular frame structure mounted for horizontal motion and having spaced apart horizontal opposed upper and lower members, said members having internal gear racks fixed thereto, a mutilated pinion mounted between the upper and lower members with teeth in position for meshing with the teeth of said internal gear racks alternately upon continuous rotation of the pinion in one direction whereby the frame is caused to reciprocate back and forth horizontally and to make one cycle of reciprocating motion for each complete rotation of the pinion, an external horizontal rectilinear rack secured to the exterior of the frame structure, an external pinion arranged to mesh with said external rack whereby the reciprocation of the frame and the resulting movement of the external rack will cause said external pinion to rotate first in one direction and then in the opposite direction and to change its direction of rotation during each half of one complete cycle of the reciprocating motion of said rectangular frame, and adjustable regulating means connecting the rack with the frame for causing lost-motion between the frame tructure and the external rack whereby the reciprocating movement of the frame structure may take place without operating the external pinion.

'13. In drive mechanism, the combination of a substantially rectangular frame mounted for substantially horizontal motion and having spaced apart horizontal and opposed upper and lower members, said members having internal substan tially rectilinear gear racks secured thereto in movable relationship relative to each member, a mutilated pinion'mounted between the upper and lower members with teeth in position to mesh with the teeth of the gear racks and to be alternately disengaged from one of the racks and engaged with the other upon rotation of the pinion continuously in one direction, said pinion teeth being arranged with a tooth thereof contacting a tooth of one of the racks before another of said pinion teeth has disengaged a tooth of the other rack, whereby the teeth of the pinion will contact simultaneously teeth of both racks without interfering with the operation due to the limited lost-motion between the racks and the frame structure, and yieldable means for opposing the relative lost-motion between the racks and the frame structure and for returning the racks to normal positions relative thereto.

14. In a drive mechanism, the combination of a rigid frame structure adapted for reciprocating motion and having spaced apart opposed members each provided with an internal and substantially rectilinear rack gearing, a mutilated pinion mounted between said opposed members and adapted for rotation continuously in one'direction, the said pinion having teeth in position to mesh progressively with "the different teeth of the said rack gearings and the said pinion being so mutilated that any one of its teeth will mesh with a tooth of only one of the said rack gearings simultaneously and the persisting rotation of' the pinion causing the said pinion to disengage alternately from one of the said rack gearings and engage shortly thereafter with the other of the said rack gearings, and the said opposed rack gearings having their teeth spaced apart abnormally and so that at the time when the pinion is disengaging itself from one of the opposed racks its tooth which will shortly thereafter engage the other of the said racks will be disposed between but completely out of contact with the two adjacent teeth of the opposed rack with which it is about teen gage and whereby when the pinion is disengaged from one rack any end pressure exerted on the frame structure that tends to move the frame will be unable to change the relation between the said tooth of the pinion about to engage the said rack to an extent that will cause the pinion to get out of mesh with the said rack gearing that is about to engage, and whereby the continued rotation of the pinion will cause the said tooth to engage the said rack gearing and make it move in the opposed direction, and the teeth of the said mutilated pinion being so spaced that after one of its teeth has started to move the said rack gearing the other teeth will mesh properly with additional teeth of the said rack gearing until the last tooth of the said pinion has left the said rack gearing, the rotation of the said pinion thus causing the frame structure to reciprocate back and forth through one cycle for each complete rotation of the said pinion, additional rack gearing externally of said frame structure and connected therewith, and a pinion meshing with said external rack gearing, whereby the reciprocation of said frame structure causes rotation of the lastmentioned pinion through the external rack gearing, said external rack gearing being controllably movable relative to the frame structure whereby a portion of the movement of the frame tructure will not cause corresponding movement of the external pinion.

15. In a drive mechanism, the combination of a rigid frame structure adapted for reciprocating motion and having spaced apart opposed members each provided with an internal and substantially rectilinear racl; gearing, a mutilated pinion mounted between said opposed members and adapted for rotation continuously in one direction, the said pinion having teeth in position to mesh progressively with the difierent teeth of the said rack gearings and the said pinion bein so mutilated that any one of its teeth will mesh with a tooth of only one of the said rack gearings simultaneously and the persisting rotation of the pinion causing the said pinion to' disengage alternately from one of the said rack gearings and engage shortly thereafter with the other of the said rack gearings, and the said opposed rack gearings having their teeth spaced apart abnormally and so that at the time when the pinion is disengaging itself from one of the opposed racks its tooth which will shortly thereafter engage the other of the said racks will be disposed between but completely out of contact with the two adjacent teeth of the opposed rack with which it is about to engage and whereby when the pinion is disengaged from one rack any end pressure exerted on the frame structure that tends to move the frame will be unable to change the relation between the said tooth of the pinion about to engage the said rack to an extent that will cause the pinion to get out of mesh with the said rack gearing that it is about to engage, and whereby the continued rotation of the pinion will cause the said tooth to engage the said rack gearing and make it move in the opposed direction, and the teeth of the said mutilated pinion being so spaced that after one of its teeth has started to move the said rack gearing the other teeth will mesh properly with additional teeth of the said rack gearing until the last tooth of the said pinion has left the said rack gearing, the rotation of the said pinion thus causing the frame structure to reciprocate back and forth through one cycle for each complete rotation of the said pinion, additional rack gearing externally of said frame structure and connected therewith, a pinion meshing with said external rack gearing, whereby the reciprocation of said frame structure causes rotation of the last-mentioned pinion through the external rack gearing, said external rack gearing being controllably movable relative to the frame structure whereby a portion of the movement of the frame structure will not cause corresponding movement of the external pinion, and a rack substantially parallel with the firstmentioned rack gearing of the frame structure and meshing with the external pinion for reciproeating movement thereby,

16. In a drive mechanism, the combination of a rigid frame structure adapted for reciprocating motion and having spaced apart opposed members each provided with an internal and substantially rectilinear rack gearing, a mutilated pinion mounted between said opposed members and adapted for rotation continuousl in one direction, the said pinion having teeth in position to mesh progressively with the difierent teeth of the said rack gearings and the said pinion being so mutilated that any one of its teeth will mesh with a tooth of only one of the said rack gearings simultaneously and the persisting rotation of the pinion causing the said pinion to disengage alternately from one of the said rack gearings and engage shortly thereafter with the other of the said rack gearings, and the said opposed rack gearings having their teeth spaced apart abnormally and so that at the time when the pinion is disengaging itself from one of the opposed racks its tooth which will shortly thereafter engage the other of the said racks will be disposed between but completely out of contact with the two adjacent teeth of the opposed rack with which it is about to engage and whereby when the pinion is disengaged from one rack any end pressure exerted on the frame structure that tends to move the frame will be unable to change the relation between the said tooth of the pinion about to engage the said rack to an extent that will cause the pinion to get out of mesh with the said rack gearing that it is about to engage, and whereby the continued rotation of the pinion will cause the said tooth to engage the said rack gearing and make it move in the opposed direction, and the teeth of the said mutilated pinion being so spaced that after one of its teeth has started to move the said rack gearing the other teeth will mesh properly with additional teeth of the said rack gearing until the last tooth of the said pinion has left the said rack gearing, the rotation of the said pinion thu causing the frame structure to reciprocate back and forth through one cycle for each complete rotation of the said pinion, additional rack gearing externally of said frame structure and connected therewith, a pinion meshing with said external rack gearing, whereby the reciprocation of said frame structure causes rotation of the last-mentioned pinion through the external rack gearing, said external rack gearing being controllably movable relative to the frame structure whereby a portion of the movement of the frame structure will not cause corresponding movement of the external pinion, and a rack substantially parallel with the first-mentioned rack gearing of the frame structure and meshing with the external pinion for reciprocating movement thereby, said external pinion having two sets of teeth spaced at respectivel different distances from the axis of rotation and meshing respectively with the external rack gearing and with the last-mentioned rack, whereby when the external rack gearing causes movement of the pinion the last-mentioned rack will move at a different velocity from the Velocity of the frame structure.

HUGH W. SANFORD.

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

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