Oct. 22, 1946. A. A. SCHWARTZ 2,409,903 MACHINE FOR SHAPING STOCK ‘ Filed Feb. 6, 1941 ' 7 Sheets-Sheet l INVENTOR Ar’fhgrA. Schwartz‘, M1 ATTORNEYS Oct. 22,1946. ' A. A. scHwAR'r‘z ' _ 2,409,903 MACHINE FOR SHAPING STOCK‘ Filed Feb. 6,‘ 1941 . 7 Sheets-Sheet 2 INVENTOR Ar’rhu§~A.Schwarkz, ‘ @244», l ATTORNEYS Oct. 22, 1946. A. A. SCHWARTZ 2,409,903 MACHINE FOR SHAPING STOCK Filed Feb. 6, 1941 7 Sheets-Sheet 3‘ . _,.w w? Amms?wam, ATTORNEYS Oct._ 22, 1946. A. A. SCHWARTZ 2,409,903 MACHINE FOR SHAPING STOCK Filed Feb. 6, 1941 7 Sheets-Sheet 4 ATTORNEYS Oct, 22, 1946.‘ 2,409,903 A. A. SCHWARTZ MACHI'NE FOR SHAPING STQCK I Filed Feb. 6, 1941 '7 ‘Sheets-Sheet 5 9998 . Fig.1., ‘Z4 . INVENTOR ' Af’mug . Schwartz, 09M, NEYS Oct. 22', 1946. A. SCHWARTZ “ 2,409,903 MACHINE FOR SHAPING STOCK Filed Feb. 6, 1941 '7 Sheets-Sheet 6 . ATT RNEYS ‘ I Oct. 22, 1946; A. A. SCHWARTZ 2,409,903 MACHINE FOR SHAPiNG STOCK Filed, Fable. ’ 1941 - ‘ FTQIO. ‘ -7 Sheets-SheyetQ 7 88 INVENTOR ArthugASchwa?z, } Mr ATT RNEYS 2,409,903 Patented Oct. 22, 1946 UNITED STATES PATENT OFFICE. 2,409,903. MACHINE FOR SHAPING STOCK Arthur A. Schwartz, Buffalo, N. Y., assignor to Bell Aircraft Corporation, Buffalo, N. Y. Application February 6, 1941, Serial No. 377,640 4 Claims. (Cl. 90—13.2) 2 1 This invention relates to methods of handling stock in connection with mass production of du plicate work pieces and to machine tools for such purposes, and more particularly to improvements in quantity production methods and machine tools for the purpose of shaping stock in accord with the patterns of templets previously fur nished. ‘ upon the stock is similarly mounted upon the table at a position opposite the stacked stock. The stack of stock pieces may be rigidly mount ed upon the work table by means of fastening devices driven through drilled openings therein. The routing mechanism is then moved into posi tion over the templet and the work stack, and a control stylus thereof is then manually guided and caused to move relative to the templet in an One of the objects of the invention is to provide a simpli?ed and improved method of handling 10 improved manner to trace the outlines thereof while the routing mechanism is operating upon sheet stock in connection with mass production the work pieces and duplicating’ the pattern of operations involving multiple routing or other the templet therein. cutting or shaping processes. Another object of The drawings illustrate a machine of the inven the invention is to provide an improved machine tool which is adapted to handle stacked sheet 15 tion as comprising a horizontal table designated generally at 20 and including suitable support stock pieces in connection with routing or other ing structure designated generally at 2|. The shaping thereof, in an improved manner. An table supporting structure includes spaced trans other object is to provide an improved machine verse beams 22 upon which is mounted a central tool which is adapted to operate from one or more templets or patterns upon one or more stock 20 rail 23 extending longitudinally of the table. The pieces in an improved manner. Other objects and advantages of the invention will appear in the speci?cation hereinafter. ' Fig. 1 is a fragmentary plan of a duplicating router portion of a machine of the invention; Fig. 2 is an end view thereof; Fig. 3 is an enlarged view of the centrol mech anism of Fig. 2, with portions thereof shown in section; rail 23 is provided with a tread piece 24 of hard ened metal with an accurately ground upper face so as to be adapted to support in smoothly rolling relation thereon a rolling carriage portion of the machine as will be explained hereinafter, The table frame is provided with a Wooden table top 25 at opposite sides of the central rail 23 (Figs. 1 and 2) . The routing mechanism includes a pair of car ' riages mounted for longitudinal and transverse movements, respectively, relative to the center rail IV—IV of Fig. 3; 23. More speci?cally, a loWer router carriage Fig. 5 is an enlarged view of the routing mech 30 is mounted upon the center rail tread 24 by anism of Fig. 2; means of mounting rollers 3| and 32 at opposite Fig. 6 is a side elevation of the machine in the ends of the carriage 3th. The carriage 30 in DO U! region of the mechanism of Fig. 5; cludes spaced parallel frame portions 33 extend Fig. '7 is an enlarged plan view of the machine ing transversely of the table 20 and provided in the region of the router carriage and carriage Fig. 4 is a fragmentary section taken along line with stirrups 34 at overhanging end portions thereof; the stirrups extending downwardly at Fig. 3 is a side view of the carriage actuating opposite sides of the table and being provided .40 mechanism of Fig. 7; with rollers 35 arranged in rolling engagement Fig. 9 is a side view of another carriage sup with tracks 36 running longitudinally of the porting portion of the machine; table. Thus, the carriage 30 is ?rmly balanced Fig. 10 is a diagram of the control mechanism upon the table and is freely movable longi of the router portion of the machine; and c 45 tudinally thereof. An upper carriage 40 is actuating mechanism thereof; Fig. 11 is a view similar to the lower portion of Fig. 3 but on a still larger scale. mounted so as to be freely movable upon the frame portions 33 of the lower carriage in direc tions transversely of the movement of the lower In accord with the method of the invention one carriage; and for. this purpose the upper carriage or more sheets of stock material such as of Dural umin or other metal as used in connection with 50 is provided with suitable rollers at ti and 42 to engage the frame members 34 and 33, respec the aircraft manufacturing industry, for exam tively. A roller 44 is also carried by the carriage ple, are mounted in vertically stacked relation 40 so as to frictionally engage the frame member upon a horizontal table portion of the machine of 33 in the region of the routing mechanism so as the invention, while a templet for guiding the operations of routing or other forming processes 55 toprovide desired movements of the upper car 52,409,903 '2 4 a5 riage relative to the lower carriage upon appli for control of the templet tracing operation. At cation of power to the roller All through a driv ing shaft d5, as will be explained more fully here inafter. Thus, the upper carriage 65a is mounted its lower end the tube 65 extends into association with a bored plate ‘H mounted rigidly upon the bracket 55; the plate 'n'l being adapted to func tion as a stop device for limiting pivoting move ments of the tube 65 upon the annulus 69. A set of four control ?ngers ‘l2 are arranged equidistantly about the collar 68 so as to extend upon the lower carriage 36 so as to be freely mov able relative thereto in directions transversely of the longitudinal axis of the center rail 25, and such movement is provided for by means of ap plication of power to the roller 44 as will be ex plained hereinafter. - A templet tracing device designated generally radially therefrom in paired relation in directions 10 both longitudinally and transversely of the cen ter rail 23. The two fingers 72 extending trans versely of the machine and shown in Fig. 3 are at 59 is mounted upon the upper carriage 45 at one side of the center rail 23, and a routing device _ arranged in operative connection with corre sponding plunger-type valves ‘l3 > which, are designated generally at 5| is mounted upon the upper carriage 45 so as to be poised, above the. table 25 at an opposite side portion. thereof upon mounted upon the bracket 57 at corresponding opposite sides of the handle ‘it and in spaced relation above the, plate 68. Thus, manual move plet tracer and the router mechanisms are oper ment of the lower handle portion ‘m of the tube atively coupled in an improved manneras will 55. toward the right as viewed in Fig. 3, for eX be explained hereinafter, whereby whenever the 20 ample, will result in pivotal movement of the tracer stylus is moved so‘ as totrace the pattern tube 65 about a horizontal axis in the plane of of a templet disposed upon‘ the table at the left the annulus ~69 so that the collar 68 presses side of the. center rail as viewed in Figs. 1 and against the valve ?nger 12' at the left side of the 2 the router device will be caused to. duplicate the pattern‘of the templet upon workpieces which 25 control device as viewed in Fig. 3. Similarly, movement of the handle portion 10 toward the may be fastened down to the table at the right left will produce corresponding movement of‘ the which the stock pieces are mounted. The tern- V hand side of the. center rail thereof. The tracing. device 59 comprises a control stylus 52 which is in the form of a tubular element having a hardened metal pointer 53v ?xed to ex 30 tendfrom the lowerlend thereof so as to be adapted to move against lateral edge portions of a guiding templet as indicated. at 54 in closely collar 88 in an. opposite direction, and such move ments of the collar will be transmitted to the associated valve control ?ngers. The valves .73 are arranged to separatelycontrol flow of ?uid pressure through corresponding conduits 15 and ‘[15. which lead to-the upper carriage moving mech anism, as will be explained,hereinafter; the con conforming fashion (Fig. 3). The pointer 53 duits 75 and 75 being fed at opposite sides of the is preferably proportioned so as to be. of ap 35 valves lil- by means of an inlet manifold 71 lead proximately the same dimensions as the routing ing from any suitable‘ source of ?uid underjpres tool which will be referred to more speci?cally hereinafter. The control stylus 52 is mounted upon the upper carriage 55 by means of an ex tendingbracket portion 55 thereof; the bracket 55 being bored, to mount the control stylus device so as to extend therethrough in loosely ?ttingrelation. The stylus 52 is ?tted with a bushing56 in the region of its mounting upon the bracket 55, and the bracket 55 is formed with a reduced annular shoulder 5‘! which engages the-bushing55so as to support it thereatv against substantial lateral movement. The bracket 55 is also fitted with resilient compression rings 58 above and below the shoulder 53 to further sup-. DQrtthe stylus 52 but to allow it to be oscillated in‘, any direction about any axis within the-plane of the shoulder 51. A pair of spacing collars 59. are mounted upon the stylus 52 above the bracket 55 so, that the lowerone rests against the uppermost resilient compression ring 58, and a thimble 6B, is ?xed to the stylus 52 by means sure, such as an air compressing or hydraulic pumping and supply-device. The valve mem bers 13 are spring pressed;so_ as to automatically return to off position when pressures thereon from the control handle ‘are released; A second pair of valves 13' of the type describedhereinabove are mounted at opposite sides‘of the control collar 68 so as't‘o be. disposed in a line extending longi tudinally of the machine for operative associa tion with corresponding control ?ngers 72 also extending from the control tube collar .58 in opposite directions longitudinally of the machine; the longitudinally disposed valves 13 being ar ranged to control flow of ?uid, under pressure through corresponding ?uid conduits 18' and 19 (Figs. 7', 8 and 10). Theconduits ‘l8 and 1.9 are also arranged to be fed from the inlet manifold 11 and toconvey ?uid under pressure therefrom to the lower carriage moving mechanism tooper ate. the latter as will also be explained morefully hereinafter. portion thereof and to, be adapted to rest against The conduits 75 and'l?; lead into. corresponding. valve devices 85 and '85‘, respectively; which are the upper end of theupper collar 59, thus sup porting the stylus 52 vertically upon the bracket 60 operatively coupled with corresponding ?uid tur 55. ~ bines 88 and 89, respectively. The turbines-88 of a set screw 5i so as to constitute an integral Adjacentits upper end the stylus 52.’ is sup ported so as to be normally concentrically dis. posed Within an enclosing tube 55 by means of spring ?ngers 66 extending radially within the tube 65. The tube 65 is suspended upon a hori zontally disposed bracket in extending from the upper carriagelill by means ofya collars}! which and 89 are mountedupon the upper carriage structure and are. operatively. connected through suitable-gearing indicated at9ii and 9| so as to “ be adapted, to causethe shaft 450i the roller 44 to rotate in either direction, depending upon. whichone ofthe turbines 88 or 8,9jis inopera~ tion at any given time.' For this purpose the is clamped about the tube 65 so astobearl against turbinesare so arranged that admission of ?uid metallic annulus 89 mounted upon a centrally 70 under pressure through'the conduit-'15'will cause boredportion of the bracket?? through which the tube 65 extends. The tube 55 is extended below the region of the spring ?ngers 66; as at 10‘, so as to provide a convenient handle adapted to'be grasped by'the operator of the machine the; turbine 88"to drive‘ the gearing in such man ner as to cause the roller 44' to move the upper, carriage'd?lto- the right as viewed» in Figs. 1 and 2. Consequently, movement of'the'controlhan dle i'l-il» so as- to» open the-valve "1-31 controlling the 2,409,903 5 6 conduit ‘I5 will cause the upper carriage to be moved toward the right as viewed in Figs. 1 trol carriage movement in either direction longi tudinally of the machine. Thus any unintended shifting of the machine carriages will be unat tended by power ampli?cation; However, upon application of the slightest lateral pull upon the and 2 until the control handle ‘I0 is released to return to its normal valve-closed position under the action of the resilient supporting members of the handle supporting mechanism. The turbine control handle ‘III by the operator of the ma 89 is arranged to drive the gearing in reverse di chine the upper end of the stylus 52 will be rection and movement of the control member so moved in reverse direction by the interconnecting asto actuate‘the valve ‘I3 controlling the con ?ngers ‘65, and thus the stylus 52 will be pivoted duit' ‘I6 will thus cause the upper carriage 40 to 10 upon the lower supporting shoulder 5'! so as to be moved toward the left as viewed in the actuate the micrometer switch control mecha ?gures. nism I00—l03 so that the control valve mech The conduits ‘I8 and ‘I9 lead to corresponding anisms 85, 86, 94, 95 are actuated to allow pas valve devices 94 and 95 which are operatively sage of ?uid under pressure through the conduits coupled with a pair of corresponding turbines 90 15 ‘I5--'I9 for operation of the turbine motors in and 9‘! mounted upon the lower carriage 30. The accord with movement of the carriages as called turbines 95 and 91 are operatively coupled for by such movement of the control handle 10. through means of gearing indicated at 98 and Thus, the micrometer switch mechanism I100—I03 99 with the roller 3! (Figs. 9 and 10) in such is initially actuated upon application of control manner that the turbines 95 and 91 are adapted 20 forces to the control handle ‘I0 so as to enable to cause the roller 3I to rotate in either direc the corresponding valve devices ‘I3 to procure the desired corresponding movement of the carriages. tion, depending upon which one'of the turbines is operating at any given time, so as to cause the Particular attention is called to the fact that the lower carriage 30 to move longitudinally of the control valve devices 13 are preferably of grad machine upon the center rail 23 and side track uate type‘whereby the rate of ?uid ?ow to the carriage moving turbines will be regulated by devices 36. The conduits ‘I8 and ‘I9 and the cor» responding valve control ?ngers ‘I2 therefore are the degree of actuation of the valve control ?n gers ‘I2. Consequently, the harder the pull by so arranged that movement of the control handle the operator against the handle ‘I0 the greater ‘I0 in a direction pointing toward the top edge of the sheet of Fig. 1, for example, will cause will be the. de?ection of the control handle and ?uid to move under pressure through the conduit the amount of fluid supplied to the correspond ‘I9 so as to operate the turbine 91 to drive the ing operated turbines will be increased, and at all times will be proportionate to the pull sup roller 3| so as to move the lower carriage toward the top edge of the sheet of Fig. 1, until such time plied by the operator to the handle ‘I0. However, as the control pressure upon the handle 70 is 35 in the event that the carriage movement so pro released. Reversely, the control valve device in cured causes the templet pointer 53 to bear too strongly laterally ‘against the opposing guiding connection with the conduit ‘I8 is so arranged templet the stylus 52 will thus be caused to pivot that movement of the control handle ‘I0 toward back upon the shoulder 51 of the bracket 55 the bottom of the sheet of Fig. 1 will cause the lower carriage 30 to move toward the bottom edge 40 against the action of the spring ?ngers 65, thus causing the thimble 60 to move laterally so as of the sheet of Fig. 1 until the control pressure to return the previously actuated micrometer upon the handle 10 is relieved. switch or switches into off position. The mi The valve devices 85‘, 85, ‘94 and 95 are arranged crometer switch thereby causes the corresponding to be normally closed but are equipped with electric solenoid actuating devices (Fig 10) which 45 solenoid valve control device to be operated to close the corresponding element of the valve are arranged to ‘be actuated to valve open posi mechanism 85, 86, 94, 95, thereby cutting off the tions in response to relative lateral movement be supply of ?uid pressure power to the correspond tween the control stylus 52 and the tube 65. For ing turbine even though the control handle ‘I0 example, as illustrated in Figs. 5 and 6, a pair of may at the time be pressed into valve actuating micrometer switches I00 and IM are mounted position by the operator of the machine. upon the carriage 40 at opposite sides of the It will be understood that whereas the control thimble 60 and to extend radially therefrom in a line transversely of the longitudinal axis of the valve devices ‘I3 and the micrometer switch devices I00 to I03 are arranged radially of the as_ machine, whereby movements of the thimble 60 sooiated control elements in directions longitudi in either transverse direction will cause the cor nally and transversely of the machine and at responding micrometer switch to actuate an as right angles to one another, control movements sociated electrical circuit leading to the corre of the control handle 10 and/or of the pointer 53, sponding solenoid device of the turbine control valve mechanism. The control mechanism is so as explained hereinabove, in directions diago arranged that as long as the stylus 52 remains in 60 nally thereto will result in simultaneous actu ation of corresponding adjacent control devices neutral or concentrically disposed relation within so as to provide a composition of control effects the control tube 65 the micrometer switches I00 whereby the router carriage wil1 move in a cor and I 0! will not be actuated, ‘and the correspond responding diagonal direction. ing turbine control valves 85 and 86 will remain A router head H0 is poised above the stock in closed condition. 65 As in the case of the arrangement of the con II I (Figs. 5 and 6), and for this purpose the head H0 is mounted upon the upper carriage 40 so as trol valve devices 13 as explained hereinabove, a to be vertically slidable thereon by means of a similar second pair of micrometer switches I02 and I03 is arranged radially at opposite sides of slide connection at II 2. The upper end of the the thimble 60 in a line‘ extending longitudinally 70 head H0 is connected through means of a link I I4‘ to a bell crank I I5 which is pivotally mount of the machine (Figs. 4 and 10), and are opera ed at H6 upon the upper carriage for operation tively coupled with the turbine control valves by a push-pull rod II‘I (Fig. 5). Rod II‘I con 94-95 so that any pivotal movement of the nects at its other end (Fig. 3) to control lever stylus 52 within the control tube 65 in directions longitudinally of the machine will similarly con 75 I I8 which is also pivotally mounted upon thecar 7 8 riage 11m» bymeans of a pivotal connection H9. The lever H8 is located Within convenientreach of the operator of the tracer control handlel't?, vention it will no longer be necessary to form laterally projecting ears or other temporary ac cessory fastening means at the side edge portions of the work sheets in order to enable them to be and'thusv convenient means. are provided where by :the operator may.‘ raise and lower the routing mechanism into and out of operative position relative to the work. It will be understood. that the router head' Hill is adapted to be ?tted with any desired type. of ?xed against lateral displacement during the routing operation, thus eliminating extra form-_ ing and handling operations. It will also‘ beun terminate the supply. of carriage moving power mounting a shaping control tracer in registry derstood that the routine of handling the work sheets in connection with the method of the in routing or work cutting tool. as .at I20, and that 10' vention is so simpli?ed as compared to methods suitable motor or other power supplying-means of the prior art that substantial economies. are will be operatively coupled with the router toolv thus made available to the user of the machine. and controlled by any suitable control device, as Because of the features of the carriage and willbe well understood‘by thoseversed in the routing actuating mechanisms full cutting speed art. is obtainable at all times Without fatiguing the Thus, a novel and improved templetfollowing operators. The cutter feed is smooth and posi machine tool is provided wherein the machining tive and fool-proof against mistakes in judgment element of the mechanism is adapted to auto by the operators who are at all times protected matically duplicate every movement of the tem from flying chips or. other dangerous in?uences. plet tracing pointer thereof, and wherein suit- In Although only one form of the invention has able movements of the carriage relative to the been shown and described in detail, it will be guiding templet and the work are obtained by apparent to those skilled in the art that the in manual application of only minor pressure forces vention is not so limited but that various changes against the control device thereof because of am may be made thereinwithout departing from the pli?cation thereof by automatically applied power - spirit of the invention or the scope of the ap pended claims. means. However, the machine is prevented from moving with disruptive or template-overrunning What is claimed is: 1. A duplicating shaping tool including a tem effects-as a result of mistakes of judgment by the operator thereof by operation of automatically plet and stock piece supporting platform, a car_ applied power cut-off controlsgwhich function to riage movable relative to said platform and whenever the templet tracer is brought to bear with the contours of templet means to' be traced, unwisellr against the templet guiding surfaces, work shaping means mounted upon said carriage in ?xed relation therefrom and adapted to dupli Thus, the machine of the invention provides mechanism whereby mass production of duplicate 35 cate contours of said templet when traced by said sheet metal products may be eifected in accord tracer, carriage movement control means. com with a simplified and economical and otherwise improved operating method. The sheet metal stock pieces may be initially stacked in super posed relation at one side of the- table while one or more templets for guiding the routing. oper ations thereon are mounted on the table opposite ly of the center rail thereof. Thestacked work sheets as explained herein above may then be Secured to the table against lateral displacement from their prearranged aligned stackedposition by means of nails or screws or other suitable fastening devices driven through drilled openings and into the supporting table. Then the routing mechanism carriage i structure of the machine may be manually di rected to move so that the routing guide tracer follows the guiding contour- of the templetiand the routing cutter correspondingly moves rela tive to the work sheets while cutting the latter. Manually controlled means for raising and low ering the" cutter relative to operative elevation is provided in conjunction with the carriage guid ing control device. Movement of the router car riage is provided for in all directions within a 60 plane parallel to the table top, and such move ment is effected by manual guiding of a control handle which is operatively couplediwith selec tively applicable power means adapted .to be au tomatically actuated to amplify the carriage mov prising a lever mounted upon said carriage adapt ed to be manually urged in the desired direction of carriage movement for partially providing movement thereof relative to said platform, pow er supply means operatively coupled with said carriage for assisting movement of said carriage relative. to said platform, said power supply means being controlled by movements of said control lever relative to said carriage under forces applied manually thereto to complement said‘ manually applied carriage ‘moving forces, and control means operatively associated with said tracer and said power supply means for inter rupting operation of the latter whenever said. manually directed forces tend to move said car riage in such’ manner that said tracer bears nor mally against templet contoured portions. 2. In a machine tool, a ?xed base, a carriage movably mounted uponsaid base, a control momber‘ comprising a tubular element flexibly mount ed upon said carriage for transmitting. manually applied pressure forces therethrough to cause said carriage to move relative to said ?xed base, power supply means operably associated with said'oarriage for complementing‘ the carriage moving forces manually imposed upon said con and until such time as such control forces may trol‘member, power'supply control means oper atively connected with said control-member so as to be automatically actuated. upon‘ movement of said control member relative to said. carriage away from control? member normal position rela be ill advisedly applied by the operator‘laterally against the templet, whereupon the power am plifying means is automatically. cut off. Thus, so-called “hunting” operation of the duplicating routing mechanism is avoided, and the mecha tive to said carriage, atemplet contacting tracer ?xed to an extending end portion. of-a member extending within the interior of said tubular member and resiliently'mounted in laterally mov-~ able relation therein by resilient mounting means, ing forces appliedthereto by ‘the operator unless nism is fool-proof as to its control ‘and operation' said tracer extending member being operatively It will be understood‘that by reason of the fea associated with second control means. adapted. tov tures'of the method-and mechanism of the in 75 control the operationof said power supply means 2,409,903 in such manner that whenever said control mem bar is shifted out of axial alignment with the nor mal attitude of said tracer extending member said power supply means is operated to assist the manually applied forces acting upon said control member. ' 10 applied thereto through said control element, and second motor control means mounted upon said carriage and in registry with said control ele ment for actuation thereby to adjustably control ' the power output of said motor means in accord with adjustable actuation of said second power 3. A machine tool including a stationary por control means in accord with the magnitudes of tion and a carriage portion movable relative pressure forces applied manually to said control thereto, carriage movement control means flex element. ibly mounted upon said carriage and comprising 10 4. A duplicating machine tool comprising a a manually operable control element movably base, a carriage mounted for movement relative mounted upon said carriage and adapted to be to said base, motor means operatively coupling submitted to manually applied forces for moving said base and said carriage for assisting in such said control element relative to said carriage and relative movement, a manually operable control simultaneously transmitting said manually ap member movably mounted upon said carriage and plied forces to said carriage for urging the latter normally disposed in neutral control position to move relative to said stationary portion, a guide relative thereto by resilient mounting means, mo contact member movably mounted upon said car tor control means mounted upon said carriage riage and normally maintained in a neutral posi adjacent said control member for actuation tion by resilient means and having a portion ex tending into engagement with said control ele 20 thereby upon de?ection of said control member from said neutral position, a tracer adapted to ment, motor means operatively coupled with said contact carriage movement guiding templet stationary portion and said carriage for provid means mounted upon said base upon movement ing relative movement therebetween, motor con of said carriage relative to said base, said tracer trol means mounted upon said carriage and in registry with said guide contact member and op 25 being movable relative to said carriage upon im pact of said tracer against said templet, and eratively coupled with said motor means for second motor control means mounted upon said causing the latter to move said carriage in direc carriage adjacent said tracer and adapted to be tions consonant with the direction of applica actuated by movement of the latter relative to tion of forces applied manually to said control element as long as said guide contact'member is 30 said carriage between motor operative ‘and in operative control conditions. disposed away from said neutral position relative to said carriage in response to de?ection forces ARTHUR A. SCHWARTZ.