Substantially in the center of the plate-33 is a hand pinion 36, to which a hand 37 may be attached@ after the dial has been placed in the bezel and before the glass face has been finahy fixed in the device. As shown in Fig. 8, a gear 38, located so as to mesh with the pinion 36, fixed to a hub 39 having a shaft 40 forced longitudiaally through its center, is placed in one of the pivot holes 72. The pinion 41 is also fixed to the hub 39 and the shaft 40. This pinion 41 then meshes with a gear 42 fixed to a hub 43 and a shaft 44. Also fixed to the hub 43 is a pinion 45 arranged to mesh with the teeth of the rack bar 25. Looking at Fig. 9 and at Fig. 3, it may be noted that a gear 51 mounted on a hub 52 and a shaft 53 also carries a pinion 54. This pinion is arranged to mesh with the gear 42 fixed to the hub 43 and in turn fixed to the pivot shaft 44. This pivot shaft 44 and hub 43 also carry the pinion 45 which meshes with the rack teeth 25. It will later be shown that the- supporting plate 33 is drilled with three pivot holes 70, 71 and. 72 which are equidistant from the center- 69 thereof. However, the distance between the holes 70 and 71 is different from the distance between the holes 71 and 72. This wM be particularly noted in Fig. 8 and Fig. 9@ whore the gear 42 meshes with a pinion 41 which is larger than the pinion 54 with which it meshes in Fig. 9. Again it may be noted in Figs. 2 and 4, where the supporting plate has been mounted at a straight angle, that a slight rotary adjustment may be made to accommodate- various size pinions which mesh with the rack bar. In each combination of -earing there will be employed gear 46 which meshes with the pinion 36. By means of spiral spring 49 affixed to a pin 50 this will act as an anti-back-lash device to hold the teeth of the gears and pinions always together. It may be noted that a part of the plate 55 may be formed as a bridge 57 whereby the pinion, 45 is located beyond the outer surface of the plate 55 in order to mesh with the teeth of the rack bar 24. After the gear unit has been placed within the case 10 and gently rotated until a proper mesh is estabeshed between the pinion 45 and the rack 24, the bezel 59 i@ placed on the device with a dial 62 and a spring 64 supported therein by a projection 63 of the bezel. The bezel is then secured in place by a spring ring 65 terminating in the bent ends 66 for easy placement and adjustment. Thereafter the hand 37 is placed on the shaft of the hand pinion 36 and the crystal 60 placed within the bezel and secured by another spring ridg 61. A feature of the invention is the use of a standard gear mounting plate which may be used for many different. combinations of gearing. Thus the mounting plate 33, wl-iose back surface is shown in Fig. 7, is provided with a bearing hole 69 for the shaft of the- hand pinion 36 and three bearing holes 70, 71 and 72, into which the various pinion and gear combination shafts may be placed. Invariably, as shown in the three front surface views in Figs. 8, 9 and 10, the shaft of the pinion gear con,bination whose pinion meshes with the rack 25 is placed in the bearing hole 71. If but a single pinion gear combination is to be used, as indicated in Figs. 4 and 10, then the plate 33 is rotated until the proper mesh between the pinion and the rack 25 is established at@the right hand side of the spindle 14. If another pinion gear combination is to be used in the train, then this pinion -ear combination is placed in either the pivot hole 70 or 72, as indicated in F-igs. 8 and 9, and the whole unit rotated by a straight angle so that the mesh between the teeth of the pinion and the rack 25 is at the left hand side of the spindle. In accordance with this feature the bearing holes 70, 71 and 72 are all equidistant from the center point 69 but the distance between the holes 70 and 71 is different from the distance between the holes 71 and 72 whereby different gear combiinations may be, accommodated and whereby the backlash gear may be fitted in at different positions after the more important measuring gears have been placed- in accordance with the varying number of .5 teeth of, their pinions. A feature of the invention is the fabrication of the pinion 7 gear units shown in one example in Fig. 6. Here the pinion 45 and the gear 43, made of material suitable for such units, are placed on a hub 42 which is then 10 expanded by having the shaft 44 forced therethrough@ By such expansion. of the shaft, the pinion 45 and the gear 43 are firmly affixed to the hub and the two will operate as an integral unit. By this means materials suitable for the functioning of each part may be em15 ployed. The shaft 44 may be of any suitable length so that its ends may be used as pivot points. Where such pivot points are exposed to wear a new pivot may be placed@ in such a unit without, abandoning the more expensive gear and pliaion elements. 20 The screw holes 67 in the case 10 are provided for attaching a back,:not shown, having a conventional lug thereon formounting the device in relation to a work piece which it will.be employed to measure. What is claimed is 25 1. In a dial indicator, a case, a spindle mounted in said case and having a movement of translation along the@ longitudinal axis thereof, a toothed rack bar slidably mounted@on said spindle, a spring for ur.-ing said spindle in a projected position relative to said case, a spring for 30 urging said rack bar alon.- said spindle in the opposite direction, another spring for urging said rack bar in said first direction, said last spring being engaged by said rack bar in a position beyond the normal active measuring range thereof, a dial, a dial hand m(yunted to rotate over S5 the face of said dial, a pinion for rotating said hand, and a train of gears intermeshing with said toothed rack and with, said hand pinion. 2. In a dial indicator, a case, a spindle mounted in said case @and having a movement of translation along the longi40 tudinal axis thereo"L, a toothed racl, bar slidably mounted on said spindle, a spring for urging said spindle in a projected pos;tion relati-k7e to said case, a sprin.- f6r urging said rack bar along said spindle in the opposite direction, a spring to oppose said second spring normally out of 45 engagement witn said rack bar arranged to be engaged thereby near the limit of the stroke of said rack bar, a dial, a dial hand mounted to rotate over the face of said dial, a pinig@i for rotating said hand, a train of gears i-@iterneshing with said toothed rack and with said hand 50 pinon anid means for limit.;ng the extent of the projection of said spindle to a preselected value. 3. in a dial indicator, a case, a spindle mounted in said case and having a movement of translation along the longi55 tudinal axis thereol., a toothed rack bar siidably mounted on said spindle, a sprin.- for urging said spindle in a projected position relative to said case, a spring for urging said rack bar along said spindle in the opposite direction, a dial, a dial hand mounted to rotate over the face of said 60 dial, a pinio-@i for rotating said hand, and a train of gears intermeshing wit.i said toothed rack and w-ith said hand pinion, characterized in this, that said train of gears consists of a hub having a longitudinal bore therethrough, a pl,nion atid a gear both baving axial aperlures in which 65 said h@,ib is tightly fixed, and a pivot shaft extending through said bore and compressing said hub radially aga-inst said pinion and said gear, thereby flxing them fir@i-ily on said h,ib. 4' -'in a dial indicator, a case, a toothed rack mounted in 70 said case and havin.- a movement of translation along the Ion.- itudinal axis thereof, an indicator unit comprising a base plate, a dial, a dial hand mounted to rotate over the face of said dial, a pinion for rotating said hand mounted in said base plate and a train of gears mounted on said 75 base plate for intermeshing with said toothed rack and

'With said han pi @d- nion, said unit being constructed and a&angdd for attachment to said -case said base plate conta 6 n -u-mber of pi-v-ot h6les -fo-r- said g-ears Q4ual to the-haaxiifiiihi -n-um-be-r of gears used in any-given combination thereof equidistantly placed fr6m said hand pimon and at varying distances- from each other for mountitig @aid train of gears in differenti combinations Of number of gears and of mul I tiplying@, values, said gears consigting of a plurality of pinion gear combinations Of various sized pinions each coupled with and seci-,red to an identical gear,: one gear in each said combination consisting of a lone gedr vrged in olne direction@by a hair spring foi constailtly exeiting-pressure on sa-id traiii oi gears for anti-backlash purposes. 5. In a dial -indicator, a case, a spi:ndle mounted in said case and - hiivin.@ a movenient of translation along the longitudin@l axis thereof, a toothed ra . ck I on said spindle, zi @t6p on said spindle to lir@it the -m- ovement of said rack along aid spindle, a sprin@ to utge-said spindle in a proji@cted- position relative, fo @-aid 6 -ase, means to selectively thang'e the e3ctent of iaiovem-ent, of said s indle and to p @djugtl-the t6nsion of said spring consisting of a,@lurality of grooves cut -in said spindle at preldetermined positi6ns and a snap ring selectively placed in one of said grooves a second spring for ur,-ing said toc)thed rack along said spindle to normally @hold said toothed rack against said stop and means for adjusting the tension of said second spnng consisting of a plurality of grooves cut in said @pindle at predetermined positions, a loose collar on said spindle and a snap ring selectively placed in one of said grooves, said collar and said snap ring constituting a lower abutm6nt for said second spring and said toothed rack,, constituting an upper abutment for said sec(>nd spring. 6. In a dial indicator, a case, a spindle in said case having a movement of translation along tlae longitudinal axis thereof, a toothed rack bar slidably mounted on said spindle, a spring for urging said spindle in a projected position relative to said case, a sprin.- for urging said rack bar along said spindle in the oi)posite direction, a Emiting spring-mounted to engage said rack bar and to oppose the ftirther movemeiit thereof beyond the normal active measunng range thereof, a slide guide mounted on said case in parallel relationship to said SDindle, a pin on said spindle and a pin on said rack bar in cooperat:@Ve relationship with said slide giiide to prevent a movement of rotation of said spindle and said rack bar, an indicator unit com.Drising a base plate, a dial, a dial hand mounted to rotate over the face of said dial, a pinion for rotating said hand mounted in said base plate ,ind a train of gears including measuring gears and a backlash gear mounted oii said base plate for intermeshing with said toothed rack and with said hand pinion, said unit being constructed and arranged for attachment to said case with one of said gears iii mesh wit'@l said toothed rack, said base plate contain@'ng a zitimber of pivot holes for said gears equal to the maximum number of gears used in any given combination thereof equidistantly placed frorp said hand pinion and at varying distances from each other for mounting said train of gears. in different combi-rations of number of gears and of multiplyin.- values Nvhereby said backlash gear may be mounted at ran-dom in any of said pivWL holes lett unoccupied after a said @ombinal.ion of measuri-Ti.- gears has been mo-Linted. 7. In a dial indicator, a case, a spir,.dle carrying rack teeth mounted i-ii said case for longitudirial -move,ment along the axis thereof, an ind-icating un;t secured to said case having a pliirality of gears of tiniform diar. qcter@ each said gear having secured thereto a pinion, said pinions being of-differetit diameter atid number of teeth, a harid pinion mounted on said indicating unit.. qa;d geafs and pinions constitutin.- a train inter-meshed between said rac"teeth and said hand pinion, said indicating unit including a base plate for mounting said gears and hand pinion and having a plurdhty of bearing h(>les, including a centrally 22799,941 located b6aring hol6 for said hand pi@ion, said bearin holes being spaced equidistantly from said pinion bear'mg Yole @-nd at va-r-' -d' ei. -whereby ymg istances one from@an6:th diff6ient c6mbinations 6f said gears t6 i)iovide different ap@plifyin -g traffis'ma b moiiiit d iip s@id':base plat y e e on e.- 8. In a di4l indicator, a case, a spindle carrying rack teeth m-ounted in said case f6r Ion2itudinal moveme-nt, alon@ !he axis thereof,-an indicating un@t secured to s'aid 4;a I s I e@havi-fig @ plurality of gears of uniform diameter and 10 number -of t-,eth, -one of said gears having a hairsprin for 9 backlash op-,ration and the remainder of said gears each having secured thereto a pinion of differing diameter Andnumber of teeth,- a ha-nd pinion mounted on said indicatiiig -u-nit-, sdid gears @and pinions constituting a train,'mter15 meshed bef@,ve-en said rack teeth and said hand pinion, said backlash gear meshing -only with said hand Pinion, said indicating unit including a @b . as I e I pla I t I e for mountin @sai(I 9 gears and said -hand pini6n and having a plurality of bearing holes, includin- a centrally loc@ted bearing h6le 20 for said hand pinion, said bearing holes bein@ spaced equidistantly fr6m said pinion bearing hole and at varying distances one fr6m another @,hereby different combinations of said gears to provide differ6nt-aniplifying trains may be mou I nted on said base plate and whereby said 25 backlash ge'ar may be mounted at random in any spare one of said bearing holes. 9. In a train of gears interme@hing with a toothed rack and -a hand pinion in a dial indicator, a plurality of pinion -gear combinations each-consisting of a gear and 30 a pinion fixed to a pivot shaft, each,said -Car and each said pinion having an axial bore, a hub for closely fitted insertion into said bores in said gear and pinion combination, said hub having an axial bore, a pivot shaft having 3,5 a diameter sensibly greater than said axial bore in said hub whereby said pivot shaft forced into said axial bore of said hub produces expansion thereof to firmly fix said pivot shaft, said hub, said gear and said pinion together. lo. in I a train of gears intermeshing with a toothed rack and a hand pidion in a dial indicator, a plurality of 10 pinion-gear combinations each consisting of a standard metal gear and @ different sized metal pinion tightly fitted over a metal hub, an axial bore extending through said hub, a pivot shaft having a diameter sensibly greater. than said axial bore in said hub whereby said pivot shaft forced 45 into said axial b6re of said hub produces expansion thereof to firmly fix said pivot shaft, said hub, said gear and, said pinion tog6ther, said pivot shaft extending from each end of said hub to for-fn trunnion bearings for rotation of said pinion-gear, said pivot shafts being constructed of '50 substantially hard material to provide trunnion bearings having the necessary hardness without affecting the physical characteristics of the remainder of the said components. I 1. in a dial indicator, a case, a spindle mounted in 50- said case and having a moveinent of translation along the longitudinal axis thereof, a toothed rack bar slidably mounted on said spindle, a spring for urging said spindle in a projected position relative to said case, a spring for ur-ing said rack bar along said spindle in the opposite 60 dir-ection, means for adjustin- the pressure of said second spnng, another spring engaged by said rack. bar beyond the end of its stroke in said opposite direction to provide a cushioned stop therefor, a dial, a dial hand mounted 6- to rotate over t]2e face of said dial, a pinion for rotating, said hand, a train of @ears intermeshing with said toothed rack and with said hand - pinion and means for limiting the projection of said spindle to a preselected value. 12. In a dial indicator, a case, a spindle mounted in said case and having a movement of translation al6ng the 70 longitudinal axis thereof, a toothed rack bar slidably mounted on said spindle, a spring for urging said spindle in a projected position relative to said case, a spring for urging said rack bar along said spindle in the opposite direction, means for adjusting the pressiire of said second 75 spring, said means consisting of a collar on said spindle

9 and means for fi--ing said corar in different positions thereon, another spring en,-aged by said rack bar beyond the end of its stroke in said opposite direction to provide a cushioned stop therefor, a dial, a dial hand mounted to rotate over the face of said dial, a pinion for rotating said hand, a train of gears intermeshing with said toothed rack and wth said hand pinion and means for Emiting the extent of the projection of said spindle to a preselected value. 13. In a dial indicator, a case, a spindle mounted in said case and havin@ a movement of translation along the longitudinal axis thereof, a toothed rack bar slidably mounted on said spindle, a spring for urging said spindle in a proiected position relative to said case, a spring for ur.-ing said rae-, bar alon- said spindle in the opposite 0 direction, means for adjustin.- the pressure of said second sprin,-, said means consisting of a collar on said spindle, a plurality of grooves formed in said spindle at different positions therein and a snap ring selectively placed in one of said grooves to fix said collar in different positions on said spindle, another sprin.- en.-aged by said rack bar beyond the end of its stroke in said opposite direction to provide a cushioned stop therefor, a dial, a dial hand 9,,799,941 10 mounted to rotate over the face of said dial, a pinion for rotating said hand, a train of gears intermeshing with said toothed rack and with said hand pinion and means for limiting the extent of the projection of said spindle to a preselected value. References Cited in the file of this patent UNITED STATES PATENTS 793,027 Burton et al - ----------- June 20, 1905 10 928, 492 Brin k ------ ---------- July 20, 190 9 Scu sa 317, 227 ------ ---------- Sep t. 30, 191 9 1,61 7,485 Hug hes ------ -------- Feb. . 15, 192 7 1,96 6,424 Am es ------ ---------- July 17, 193 4 2,010 057 Buckwalter ------------ Aug. 6, 1935 15 2,178,745 Em,ry ---------------- Nov. 7, 1939 2,210,435 Ruf ------------------ Aug. 6, 1940 2,484,771 Worthen --------------- Oct. I 1, 1949 2,527,173 Boat ------------------ Oct. 24, 1950 2,645,857 Andersson ------------ July 2 1, 1953 20 OTHER REFERENCES "Starrett Dial Indicators" 2nd. ed.; published by The L. S. Starrett Co., Athol, Mass.

Un'lted States Patent Office 2,799,941 21799,941 MULTI-RANGE ADJUSTABLE DIAL INDICATOR 5 GAUGE Alfred HaniRton Emery, Poughke-,ps'@e, N. Y. Application March 15, 1954, Serial No. 416,238 13 Claims. (Cl. 33-172) This invention relates to dial indicators of the rack and 15 pinion type. The object of the invention is to provide means including a stock or a kit of a minimum number of parts for adjustin g the device over variable limits to the different ranges of the device and the correspondin- indicator 20 means within each such ran.-c. in each case where the limits of a given range -are fixed the reading dial pointer is correspondingly adjusted for a full scale indi-zation. Wherea s prior art devices have always required a separate spindle for each individual range, the present inven- 25 tion requires but a sin.-le spindle which may be universally employe d through the use of simple means for limiting the movement thereof to correspond to the particular range to which the device may be adj'ustcd. Such means takes the form of a simple stop whereby the amount by 50 Nvhich the feeler end of the spindle may protrude from the casin.- corresponds substantially to the rang.- to which the device may be adapted. The simple stop may take a varielly of forms, su..-h as washers, shims, inverted caps or collars, or a simple snap 35 washer inserted in a recess machined in the spindle itself. From the standpoint of economy and simplicity the simple washers, each of ivhich effecti@ely shortens the spindle by a given amount, are effective and practical. The preferred embodi-,nent of the invention, however, aiad. that 40 more in keeping with the nature and the object of, theinventio n, consists of a plurality of recesses machined in the spindle into any one of which a sprin.- steel snap -washer may be fixed. By this means,no provision nled be made for safe and convenient stora-e of the small 45 parts of a kit dliring the times the dial indicator is being. used with a particular adjustment. Again, prior art devices reqiiired a large number and variely of @ears and gear supportin.- members to adjust and vary the degree of magnification between the feeler 50 or probe and the indicatin- pointer. A feature of the present invention is the use of a minimum number of pinion and gear combinations adapted to be mounted in a standard arrangement of bearing holes not exceeding the largest number of gears used in any one combination. In 55 other words in accordance with the present invention, a single pair of gear supportidg members have been provided with the bearing holes spaced and located in such a manner that @ear and pinion combinations may be interchan-ed to provide different ratios while supportod in 60 said bearin,a holes without any additional supports. Another feature of the invention is the use of different numbers of -Cars in a train, still usin.- the same minimum number of bearing holes but with provision for effectively mountinthe bearing plates at -a straight angle to accom- 65 modate the chan-e in direction of the pointer when a change in the number of gears is made. By way of example it will be noted that when but a single pinion and ,-ear unit is interposed between the rack and the hand pinion, the rack will be on the right hand side of the 70 spindle, whereas when two pmion an gear units are introduc ed into this train the rack will be on the left hand ra-Len-@@ed July 23, 1957 2 side of the spindle. By the same tOKen the -car supporting member will be mounted at a straight -an,-le in the two cases. A feature of the invention is a symmetrical design and constr-uction of the casing whereby th-. means within may be mounted in what may be termed either a right or left hand arran-ement. By this means fbr right or left hand mountin,-, the gear supportin.- members having a minimum number of bearing holes formed therein in a standard arrangement and a minimum number of lo standard pinion and -ear combinations, a large number of different range dial indicators may be produced. Through such an arrangement supplemented by a kit of a very few parts' a user of the device will be enabled to r,-adjust the device to different rad.-es and thus avoid the purchase of a plurality 6f such indicators to fulfill his needs for different ran,@e instruments. Another feature of the inventioii is the use of a centrally located bearing hole for a hand pinion and a plurality of gear bearing holes all located equidistantly from said pinion bearing hole but at varying distances one from another. The -ears mounted in these bearing holes ate all of uniform diameter and number of teeth but each has mounted se-curely a different sized pinion so that varying multiplying combinations may be selected and mounted. One gear, not provided with a pinion but instead provided with a hairspring constitLi@Les a backlash arrangemeint and since thisgear is also of the same dia-meter it may be mounted at random in any one of the bearing holes, left after the selected @combination of multiplyin.- gears has beell mounted. A feature of the invention is a novel fabricated pinion and gear combination in which botha pinion and a gear are placed on a comrion cylindrical hub carefully aligned on the axis of these members and into whi-ch a hardened rod is forced whereby both the pinion, the gear and the axial rod are firmly gripped and will thereafter function asaunit. Bythisarran.- ementthesaidrodwhich-maybe of hardened steel, bronze, tun,@sten carbide, or any other desirable material, may be -- mployed as the bearing pivots by which the -assembly is located for rotation. Also, by this arran,-ement the pinion and .-cars may be made of lightweight or otherwise suitable durable material such as brass or steel and the hub may be of slich li,-ht material as magnesium, aluminum at@d so forth. A.-ain, by this construction, re@Dairs may be easily made by replacing the pivot shaft or center rod when this becomes wom rather than replacin.- the far more expensive pinion and gear assembly. Thus, each part of the assembly may be fabricated of the material most suitable for its particular function so that compromises necessitated by integral construction of -Car wheels and pivots therefor are avoided. Another fea:ture of this construction is that the center rod or pivot shaft may be made of dift'erent len,-ths, as when the pivot shaft of a given unit must extend throu.-h the face of the device to carry @a tell-tale hand which acts as a revolution counter for the lar@e hand. Another feature of the invention is a shockproof construction for protecling the delicate mechanism of the gear train from damage at the far end of il,S travel. Means for avoiding the iH effects of sudden starting of th-- movement of such gear train are convenciolial, and such conventional means also protect the device against a sudden and violent return to normal position. iii accordance with the present invention, additional means ol' a novel nature is provided to protect the mechanism against a sudden and violent stop when the spindle is moved forwardly beyond the range of the instr-ument and the movement of the spindle is stopped by encounter w-ith the frame of the device. Here the block slidably mounted on the spindle is spring mounted so that it will not respond to a sudden and vi e ar movement o t c spi e, ut wi ow at suc a rate that no injury to the -Cars will be causedi

2,799,941 In addition, just before the spindle comes to a sudden and violent stop the rack block wiR tend to continue its movement and will come to a stop slowly through encounter with a cushioning spring. In a preferre(I form of the invention this cushion spn'ng takes the form of a 5 leaf spring secured to the frame with its free end placed so that the rack block will encounter it just as ibe hand pointer comes to the end of the scale. Another feature of the invention is a means for adjusting the force exerted by the spring used to hold the 10 sliding rack block upward. This is the conventional spring which gives way when the feeler or probe is pushed in too suddenly or violently and which protecfs the gear@ - ing, against shock. Since the load on this sprmg varies with the amount of the magnification of the movement 15 provided by the gears, a nic-I adjustment between quick response of the device and protection of the gears may be had by making this spring adjustable. It-is, of cour@e, obvious that a diff.-rently loaded spring m-ay be used 20 with each different train of gearsi-but in keeping with the object ol' the present invention, the same effdct'may be attained by using means to vary the dim@nsidn of the compressed sprin,-, thus leading to economy in manufacture or, alternatively, to adjustability of the d- ' @vice in 25 service. Like the means employed for adjusting th6 effer-tive length of the stroke of the device, the present means may tak@ a variety of forms, but here again the preferred forin is similar to that used before, that is, the sp@iiidle has 30 machined in it at convenient distances below the lowermost surface of the rack bar a series of recesses into one of Which, selectively, a snap washer may be placed as a stop for the said springOther features will appear hereinafter. The drawings consist of two sheets, having ten figures, 35 as follows: Fig. I is a perspective view of a dial indicator -auge; Fig. 2 is a view partly in section looking into the gauge, from the rear; 40 Fig. 3 is a sectional view taken on the line 3-3 of Fig. 2. Fig. 4 is a view similar to F@g. 2 showing how the sli@e. guide and other elements may be mounted in the case at @a straight angle so that a different alignment of gears may be used1 45 Fig. 5 is a -roup of fragmentary sketches partly in section showing alternative methods of adjusting the range of the instrument: Fig.. 6 is a sectional view of a single pinion gear comb-ination showing how these elements are fabricated; .50 1-ig. 7 is a view of the indicator gauge looking at the device from the front after the gear unit has beeh attached thereto but before th-- dial and the bezel have been placed thereon-, and Figs. 8, 9 and 10 are three different views of the base 55 plate on which the gears are mounted shoviing three different arrangements of the assembly of the gear train to iJIustrate the manner in Nvhich different rahge devices may be assembled on a universal base plate. I,a the drawings there is shown a dial indicator com- . 60 prising a case 10 having a protruding lower stem 11 aiid an upper stem 12. These steriis are provided with bushings 13 which support a work actuated spindle 14, havin.- a work enga,-ing contact 15 at its lower end@ A guide 65 pin 16 fixed to the spindle 14, prevents its rotation by - I being restricted to move in a direction parallel to the axis of the spindle 14, in a slide guide or, elongated slot 17 in a bracket 18. The bracket 18 is secur6d to the case 10 by two screws 19. 170 It be clear from Figs@ 2 and 4 that the bracket 18 may be mounted either on the right or on the left hand side of the case. It will later appear that this arrangement is made so that different gear comb,-iiall-ons may be established s'mce -a change in the number of gears in- 75 volves a change in the direction of rotation of the hand pinion 36. The spindle 14 is urged in a projected direction with respect to the case 10 by means of a compression spring 20 slipped over the spindle 14 with its outer end in contact with the bushing 13 and its inner end in contact with the corar 21 fixed to the spindle 1-4 and resting against the guide pin 16. The projected movement of the spindle 14 is limited by a snap ring 22 which is inserted in- any one of the grooves 23, selected in accordance with the range to which the device is adjusted. This feature of the invention is shown in some detail in Fig. 5 -wherein the means for adjusting the apparent length of the spindle to provide for diiferent ranges is shown in three alternative forms. In one formi that shown in the fra,@mentary sketch to the left, the spindle is el'fectively shortened by the placing of a washer 6 under the head of a ictaining scr'ew -5, -whereby the -space -betweeli the upper end of the probe or feeler 15 and the lower surface of the bushing 13, as indicated in Fig. 2, is shortenend to correspond with the range for which the device is adjusted. In the second form, shown in the middle fragmentary sketcb of Fig. 5, an inverted cup-like piece 4 is used instead of the washer 6. This cup-like piece: has the merit that it may be tightened to the spindle 14, by the retainiuz screw 5. The third and preferred means is shown in the right hand fragmentary sketch of Ffg. 5 and this consists of a series of grooves machined into the spindle 14 and in which a s-@iap ring 22 may be selectively placed. It may be noted that if these dial indicator galiges are supplied to customers along with a kit of parts whereby the customer may adjust the device to different ranges, that the preferred forpi of this range adjusting means does not involve extra parts which must be carefully stored but relies only on the sin,-le snap ri-@ig 21 ",hich wiff always be placed in one of the various grooves 23. Slidably mounted on the spindle 14 is a block 24 provided with a rack 25 along one of its edges, the teeth of which wiH mesh with the teeth of a pinion 45. A guide, pin 26 rigidly fixed to the edge of the block 24 opposite the teeth 25 prevents rotation of the block 24, since this pin @ is also guided in the slot 17 of the bracket 18. Sliding block 24 is urged in the direction toward and into -contact with guide pin 16 by compression spring 27 slipped over the spindle 14. One end of the spring 27 abuts the lower end of the sliding block 24 and the other end p:ushes against a collar 28 which rests against a @nap ring 29 inserted in any one of a number of grocives 30 formed in the spindle 14. Changing the snap ring 29 to: one groove from another varies the spring pressure applied to the sliding block 24.by the spring 27 to furnish different amounts of pressure for driving different combinations of gears. It will be obvious that a greater spring pressure will be needed to drive the indicator hand when the range, of the instniment is smah. Fastened to the case ]LO by means of a screw 311 is a resilient limiting stop 32 to arrest the inward movement of the block 24 slightly before the inward movement of the spindle 14 is stopped by the contact between the work engaging prob 5 an e lower end of stem 11. This spring, which ay be in the form of a leaf spring, constitutes a cushionin.- means normally out of engagement widi the rack bar 24 ' but constructed and arranged to perform its function as the,dial indicator hand reaches the limit of its travel. A gear traiii unit is made up essentially of a base plate 33 and a cooperating plate 55 held together by stand off cohars 56. Such a unit may be fully assembled and, with its various gears, placed into the case with the teeth of the pinion 45 out of mesh with the rack 25 and then rotated gently until a proper mesh between this pinion and the rack is- established. Thereafter the plate 33 -may. be fixed in place and secured to the front face of the case by the screws 34 inserted through the elongated slots 35.