US1284930A - Electrical hammer and stone-cutter. - Google Patents

Description

v 1 1. ROBERTS ELECT RICAL HAMMER AND STONE CUTTER. APPLICATION FiLED AUG. I7: I915- 1,284,930. Patented M612, 1918.

4 SHEETS-SHEEI l.

1.]. RUBERTS.

ELECTRICAL HAMMER AND STONE CUTTER.

APPLIC ATlON HLED AUG. 11. ISL)- Patented Nov. 12, 1918.

4 SHEETS-SHEH 2.

J. J. ROBERTS. ELEGIINCAL HAMMER AND STONE CUTTER.

MPUCATXON FILED AUG. \7. I913.

l'utcnted NW. 12, 1918 J. L ROBERTS.

ELECTRICAL HAMMER AND STQNE CUTTER.

APPLICATION FILED AUG. 5]. 9H,.

Patented Nov. 12, 1918.

4 SHEEIS-SHIEI 4.

Unrrnn srn'ms PATENT OFFICE.

JOHN J. BOBEBCQB, Orpbmavtmjp nuruoxy, assxenon. 'IO worrnoca'rmo nLac'rnIc m1. column, or LomvILLn, KENTUCKY.

amoral oer. alumna m arena-comma.

To all whom it may concern.-

- Be it known that I Joan J. Roam, a citizen of the United States residin at Louisville in the county of J efi erson an the State of kentucky, have invented new and useful .Im rovements in Electrical Hammers and tone-Cutters, of which the following is a specification.

My invention relates to electrical hammers and stone-cutters wherein new and useful designs in the construction of electromagnets of the solenoid type have been devise and new and useful means of operating and controlling said solenoid magnets through automatic and manually controlled electrical switches.

The objects of my invention are,(1) to develo an electro-magnet of such a design as will generate and conserve for eiiicient circulation in a predetermined pathway of iron parts and intervening air-gaps in its field and armature the maximum number of magnetic lines for a given wattage of current and size of magnet; (2) to provide an electr0-magnetic hammer of such shape and construction as will, at a certain desirable temperature, dissipate the inte nally generated heat units as rapidly as they are generated in normal operation, so that the hammer may so operate continuou 1y at adcsirable'temperature; (3) to cons not an electrical hammer of such. design t at the metallic impact of the hammer blows in normal operation shall take place outside of the magnetic field of said hammer; (4) to provide for an electric hammer a solenoid I magnet with sliding, cylindrical armature of novel design adapted to direct the magnetic lines of'said solenoid across the variable air-gap between the armature and the metallic field when energized; (5) to provide a new and useful electric switch of the'cupand-ball type having the fixed and the movable terminals adapted to make contact with each other promiscuously in a diversity of places in normal operation so that any one place on the contacting surfaces of the terminals touched at any one stroke of the switch, may have time to cool somewhat while contacts are being made in the succeeding strokes on various other places over the contact surfaces of said terminals; (6) to, devisenovel and simple means for operating said electrical hammer automatically through said cup-and-ball switch with the lpectfleatton of Letters Patent.

Application on a n: 11, 1915. Serial Io. 40,007.

Patented Nov. 12, 1918.

alternate inward and outward impulses of said armature; (7) to provide novel means for cushioning the inward stroke of said armature to avoid metallic concussions in themagnetio fieldd' l(8) to provide novel mechanism for rea y modif 'ingithe force of the hammenstroke and a so cans for controlling the frequency'of the hammerstroke; (9) to provide a new and simple manually operated electrical switch adapted to start or stop the operation of the electric hammer at the option of the operator; (10) to provide novel means for readily changing the solenoid coil in the electrical hammer for another coil of the same size adapted to a different voltage; and (11) to provide novel attachments or said electrical hammer whereby the hammer form may be quickly changed to the form of an electrical stonecutting tool. All of these objects are attained in the present invention, and the electrical hammer and stone-cutter illustrated in the accompanying drawings which form a part of this specification. is a practicable apparatus embodying the aforesaid novel means and other new and useful details of construction, arrangement and combination of parts, all of which, together with their functions will be described in detail with. reference to said d'rawings,'and will be definitely pointed out in the claims that follow the description.

In said drawings, Figure I is an elevation of my electrical hammer casing assembled ready for operation. Fig. II. is a combination of a longitudinal section of the hammer and casing along the axis, with the manual and the automatic switch mechanism showing intact in elevation. Fig. III is a detail view, in elevation, of both the manual and the automatic switches and their contiguous and co-acting parts in their normally operative positions in respect to one another andto the electro-magnet, a fragmentary, longitudinal section of which, is shown in said Fig. III. Fig. IV is a view similar in every respect to Fig. III, and containing the same parts, but some of them are here shown in a diiferent operative position from those of Pi III.

Fig. V. w ich resents a view in every respect similar to that of Fig. IV., even to the relative positions of the moving parts, shows a modified form in which the conductors for the electric'current of the solenoid are all insulated from the ground of the hammer, as will be fully explained below.

Figs. VI. and V 11. show horizontal projections of hammer-cap 8 and tool-cant) respectively detached from the sprlng-casln g 7.

Fig. VIII. shows a side elevation of one of the tools 7 5 adapted to fit operatively into tool-cap 9.

Fig. IX. is a vertical projection of arm 64. with its contiguous parts 72 and 74 appearin in cross-section.

ig. 'X. is a detail view of a fragmentary, longitudinal section of my electrical hanr mer in a plane of the axis, showing the tooloap 9 attached and the stone-cutting tool 75 inserted therein and resting against the hammer-face 29 in position for operation.

Fig. X1. is a detail view of. the-terminalend 22 of the solenoid spool, showing the coil-terminals 19 and 19" anchored in the insulated terminal-plates 2-1 and 24 respectively.

Fi X11. 's a side elevation of the tar mine -'end 22 of the solenoid spool and a fragment; of the coil 19, showing the 1nsulated tenninal- plates 24 and 24 in elevation and the s ace 26 between them.

Fig. X 11. is a vertical projection in detail of the inner part of the head-cap 5 adapted to fit operatively to the terminalend of the solenoid spool as it appears in Fig. XL, the iron part 18 fitting inside the s col-cylinder 33 and the insulating blocks 2 fitting into the deep s aces 26 between the terminal plates 24 an 94, as shown in Figs. XI. and X11, while contact- springs 25 and 27 rest against terminal- plates 24 and 24 respectively, as shown in Fig. III.

Fig. XIV. is a side elevation in detail of the head-cap 5, of my electro-maguet. showing in elevation one of the insulating blocks 26, the two contact- springs 25 and 27, with the two shai 'p contact-points 25? at th raised extremity of spring Spring 52 7 has similar points.

Fig. XV. is a detail in elevation of my automatic switch of the cup and ball type showing the contact surface 332 011 the oval contact-end of the fixed terminal 59, and the cup-shaped contact-end 53-" of the movable terminal 53. i

This invention has been develo )ed for general use where an efiicient poweriammer or stone-cutter, large or small is desirable. It can be readily attached to a sup )orting frame of any desirable kind and so le t alone with its switches properly adjusted to work; by itself indefinitely, as in pumping hr other reciprocating-motor service. With this general purpose and the special objects afore' said in view, I will now describe my invention in detail, pointing out and explaining the uses and the operatlons of the various parts and combinations thereof throughout my invention, as illustrated in the drawings shown in Fig. 11., where also may be $00.

that, into a central perforation and counter- .horing in ca 1 3, I have fitted loosely an insulating pus -pm 1, movahly secured there i by means of the cross-pin 4. Puslrpin 4., .when the hammer is not operating, is nm' mally held in its'outer position, as in Fig.

II. by the spring-arm 46 clamped rigidly to binding-post 45 by means of the thumh-nut 44 which also clamps the end of electric wire 42 to binding post 4:"). Said binding post is insulated from plate 39, but rigidly clamped thereto b means of the nut 45" and the insulating locks 45.

Plate -l7 fastened tothe under side of arm 46near its outer end is one terminal of the manually operated switch of the hammer.

while the other terminal of said switch is the tapered end 48 of the post 51 insulated from plate 39 but fixed therein by means of nut '49 and the insulating blocks S0. Into post 51 is rigidly fastened the contact part 52 which forms the fixed terminal of the automatic-switch, the movable terminal being the part 53. When the hammer is at rest, therefore, the normal position of the manual switch 47-48 is open, while that of lhe automatic switch 52-53 closed. as shown in Fig. 11. But when it is desirable to operate the hammer, push-pin 4 resting against s 'Jring-arm 4G is pushed inward forcing arm 46 to bend enough to press terminah plate 41 a ainst terminal-post 48, as shown in Fig. I so that the current may pass through post 51 and the automatic switch 52 433 to the solenoid coil. as will be more fully explained hereafter. It should here be observed in Fig. III. that the reciprocating tappet-rod 72, slidin in and out of the channel 72 through t e parts 19, 5 and 30. is now on its inward stroke under the impulse of spring-pressed arm 64 hinged al pintle 66 and engaging rod 72 at hinge-stud 67 and that tappet-disk 70, fastened rigidly to rod 72 With pin 71, has engaged tappet 58 of switch-segment 55 and is rocking that segment inwardly against the force of spring 56 coiled around pintle 57. This act would soon rock segment 55 inwardly fal enough to brin the switch- terminals 52 and 53 together,53 eing mounted on segment 55 by means of the flexible arm 54. Said act would also rock segment 55 inwardly far moving with rod 72 has p1 s locked in its inward position with the switch-terminal 53 pressed against switch terminal 52 for a predetermined time, as will be hereafter shown. It should be noticed that the reciprocating tappet-rod 72,

'10 under the impulse of the inwar ly plunging armature 16, Fig. II., as will be hereinafter explained, is shown in Fig. IV. on its outward stroke; and that tappet-disk (39 already engaged 61, a rigid part of detcut 60 hinged on pintle 63, and in this act would soon move tappet 61 far enou h to disengage detent (30 from notch 59. nd segment 55 thus released iwould suddenly rock back with its switch-terminal 53' to the position shown in Fi III.

It should also be observed that the parts 37 and 3:7", attached to arm 64 at crank-pin 38, move downward and upward with rod '72 and arm 64, as shown in Figs. III. and

IV. respectively.

In Figs. 11., III. and IV., I have shown that the pathway of the electric current for energizing the solenoid coil 19 enters the ground of the hammer in the switclrterminal 53 and passes out through screw 73 and contact-spring 27 to terminal plate 21*,

and thence through the solenoid coil 19.

The head-cap 5 of the electro-magnet is threaded around, as shown in Fig. XIV.,

and provided with a shoulder and adapted to be screwed securely into the head-end of casing 1 of the electro-magnet, until said shoulder impinges on the plane end of casing 1, as shown in Figs, I. and II. Headcap 5 is also provider with a central perforation 72, concentric with which on the inner side is a comparatively large counterbore into which is closely fitted and screwed the threaded end of armature block IS; the

other end of which block 1& provided with a large deep, central countersink adapted to receive the obtruncated conical end 17 of the reciprocating, cylindrical armature 16 which in operation slides back and forth,

well-fitting, in the chanucl formed by the hollow metallic cylinder 23 of the solenoid spool on which is wound and fixed the insulated wire coil 19, as shown in Fig. II.

65 And the insulating Washers 21 and 2:2, in

Figs. II., XI. and XIL, securely swagcd on over the ends of cylinder 23, constitute the flanges of said spool. Now, the perforation 72 of head-cap 5 is extended on through block 18, as illustrated in Figs. II. and III.

The tail-cap 6 of my elcctro-magnet is provided with a shoulder and a reduced portion with threaded perimeter similar to head-cap 5, as illustrated in Figs. II. and

XIV., tail-cap 6 being adapted to be screwed securely into the tail-end of casing 1,j'br1 n 1 around with a fine, V-shaped, helical groove,

presenting a shallow-threaded surface, and

also similarly threaded is that portion of armature-shank 14 which is directly opposite the threadcd wall of boring 6 while armature 16 is in its normal position of rest. These adjacent surfaces are threaded to facilitate the passage of the magnetic lines of force through the sui faces of the adjacent parts,.at the moment when said armature is starting on its inward stroke.

Concentric with said boring 6 at its inner end is a shallow counterbore 6, into which is swaged a metal washer 20 flush with the inner face of cap 6. Now, the shoulder 15, a 45-degree bevel, is the reduction in diameter of armature 16 to the smaller diameter of tll'llliltlllQ-Hllt!11k 11. And the central perforation in washer 20 has a diameter less than the diameter of the central boring 6, so that the inner rim of washer .20 cvtends inward slightly beyond the threaded wall of boring 6; and the inner edge of this rim of washer 20 is beveled and adapted to fit evenly against the beveled shoulder 15 when armature 16 is resting in its outermost position, as illustrated in Figs. II. and X. Washer 20, therefore, serves as an abutment for shoulder 15 of armature 16 in its outward plunge, should the hammer-head fail to meet with other resistance sufficient to arrest it in the hammer-stroke. It should also be explained here that the central perforation in washer 20 has a greater diameter than armature-shank 14 which passes through said perforation without touching washer 20, the bearings of said armaturehammer being channel 23 and the central boring in stay-block 12.

In my electro-magnet, as illustrated in the drawings herewith, the armature 16 with its essential parts 11, 15 and 17, and the casing 1 with its caps 5 and 6 and their parts and joints, have all been studiously designed, both in their relative delineations and in their con'iparative sizes, through ex tensive experimcntation. and so adapted to carry in this prcdctcrminml pathway of eflicicnt circulation a very high percentage of the magnetic lines generated within the solenoid coil, to the end that the most powerful hammer-stroke possible may be delivered for agiveu wattage and size of magnet. The iron casing-caps and (5 are both comparatively heavy and roundshouldcred to counteract lackage and straying of magnetic lines as they make their end-turns from armature or casings. The obtruncated conical nose 17 of the cylindrical. sliding armature 16 is adapted to it into the deep, central countersink of arnmtnre'hlock 18 on the inward strokc of armature it Thus the parts 17 and 18 are ndaptcd to allow a long recipro rating movement of armature 145 with a. mmparativcly narrow air-gap '17. Thus I have, in a. great nuunure, countcractrd the magnetic rvlnr-tanrc of the rariahlc air-gap 17 of opcration. Also I should explain tl at, the peculiar shapes of the parts 17 and 18 and tho crmstricted net-k 14 of the armature 16, haw all been adaptcd to rongest the magnctic lines toward the axial none of armature 16 to help minimize tho temicncy of said lines to leap across between casing l and armature l6 instoad of crossing the airgzip 17* of operation as lines of etlicicnt force.

Metal stay-block 12 has boon adnptwl to fit ('loscly on tho outside of tail-cup (3 to which it is norm-cl fastened by memoof the screws 13, 1-3. Fig. ll. Staphlork IE1 is provided with a large rcntral boring adapt (.tl to allow the mn'r-tlirradml outer ond of urmature-shunk ll and also the inner end of hamn'ler-ncck 10 to slide through easily. though close fitting. And block 1:2 is also threaded around its periinct'or. Now. springcasing 7 which incloscu hammeriring 1l. in provided with a thread around the lllfiltlt, of the inner cnd and with z: howled cdge, and has been so ndnptcd to ho sit-rowed on to cin'ely over block 112, fitting cloe lv against cap (5, as shown in Fig. ll. The outer end of raising 7 is also threaded around thrinside circumference and adapted to rccrirc and hold hannncrrap or toolwap ll whoso innor ends arc [hi-curled around as shown in Figs. VI. and VII... and othrrniw n-la itml to be securely srrewcd into the ontcr mid of springwasing T, as illustrator]. in Figs. ll. and X.

To further counteract lealoigc and tiaying of the magnetic lines l'rom riiit-it-nt rirrulotion through my solenoid mag'iut. tho arnlalurcshanlr 1% ul its outvr onil has lit'll tcrminated in a convrr nurture. and runt'ally bored to a suitahhlijdll. nhi'h hon ing is threaded. 'l'hcn tho nmcr cud ol llillltmcr-neck 10 is concawd and fusltionml ith central threaded post 10 and ll lilllltll to screw securely into shard: ii so a to lit crcnly against; uaid route-x surf. 3c of tho end of shank 14, an shown in Figs. 2!. and. X. Said hannner-nt-rh 1U 15 inznln of 1 ion!- able non-magnetic niot'al alloy. prclrrahl v containing phosphorus and a high ilct'tvnfl ago of copper. which I have found to he din magnetic to a marked dcr'rrc under tho of foot of the rapid operative altcrnntiono m the elcctro-magnotin field. 'lhcsc facts, therefore. both of contour and of romp sh tint in th\ no parts deflect tho axially inclined magnetic lines of force, dcsirpble declination along the plan:- of (rusing-cap 6 where they readily pass tho slight bonding thmn to the air-gap between said casing-ca and armature and so are conserved for e cient circulation, as I have previously set; out among the objects of my invention.

In the outer end of hammer-neck 10 is a large central boring with threaded wall. The steel hammer-head 29 with slightly convex face has a larger diameter than neck 10, and is provided on its plane inner side with a heavy central lug 29 threaded and adapt ed to be screwed tightly into said central boring until the plane outer cndof neck 10 impinges on the plane inner side of head 29 in an even joint which is then made fast; by means of a pin 29 swaged into a transverse boring through neck 10 and lug 29", as shown in Figs. II. and X. Hammer-head 29, asl have said above, has a greater diamotcr than hammer-neck 10, and is also adapted to act as an abutment for the main spring 11 of the hammer, which has been fitted on over hammer-neck 10, so that the inner end of said spring abuts against; stay-block 12 while the outer end of said spring pushes against the rim of the inner side of'hammcrhead 29, between which two stays said spring is held under desirable tension for the normal operation of the hammer.

In Figs. III. and IV the stay-block 30 is a large disk of non-magnetic metal which constitutes the foundation of the switch mechanism and its housing. The outer or upper face of block 30 is plane, while the inner or lowcr face is concavcd and adapted to fit centrally and evenly on over the outer side of head-cap .5 to which block 30 is figidly fastened by means of the screws 31, 31, as shown in Figs. III. and IV. Around its perimeter block 30 is threaded; and switchcasing 2, a hollow cylinder of nonmagnetic metal is also threaded around on the Inside from. its inner or lower and back a little way, and its end section is provided with a bevel made to lit the curvature of the shoulder of head-cap 5, said 0nd of casing 2 being so adaptcd to he screwed on over gtay-block 30 until the hon-led 0nd of casing 2 is forced tight y against; the rounded shoulder of llicad-cap 5. as illustrated in Figs. I.,'-1I. and

Into the upper side of stay-bl0ck 30 at equal intervals around the disk near its edge, arc fastened by means of threaded lugs, three squareposts, 35, 35' and 35, of nonmagnetic metal, as shown in Fig; III. Post 35 in the foreground near dash-pot; 36 is in fragments contiguous to block 30 and disk 35') ahovegpos't 35 is shown plainly in the hackgrotzml of Fig. III; and post 35 is shown in said figuresmell to the left near switch-p( )st- 51. These three square posts, 35. 35 and 35 form. the rigid support for plane disk 39, binding post; 43' insulated from disk 39 by, means of the ins. ting blocks 43 Bindupon which is mounted thev ing-post 45 and switch-post 51, as I have previously explained, are. alsomonnted i disk 39. There is a central rforation also in disk 39, into which on t e inner side is 5 swaged and soldered the short metal tube 65, said part being adapted to allow the outer end of the reciprocating tappet-rod 72 to pass entirely through it, as shown in Figs. IV. and V., and sleeve 65 acts as one of the bearings of tuppet-l'ud T2, the other bearing of which is the central perforation 72 in head-cap 5 continued through blocks 18 and" 30. Fig. III.

Pintle 57 is fixed into one side of ost 35, and against the opposite side of suit post is clamped by means of screws 74 the metal plate 74 into which the'pintle 66 of arm 64-. and the pintle 133 of detent 60 are fixed, see Figs. I'II nd 'IV.

Spring is coiled around pintle 57 to actu ate seg'meht 55 outwardly has its lower end braced against block 30 and its upper end 'looped over segment 55 and bearing against the extended portion which carries arm 54, Figs. III. and IV. Spring 62 coiled around pintle fifihas one of its ends looped over detent 60 while the other end is braced against post 35, Figs. III. and IV.

The air dash-pot 36 1s mounted on block 30 by means'of two ears 34 fastened to block 30 with screws on diagonally opposite sides of said dash-pot and two lugs 33 fixed in the opposite sides of dash-pot 36, and adapted to act as p intles in the perforations in said ears, as illustrated in Figs. III. and IV., so that dash-pot 36 may be easily rocked back and forth on a radial line of stay-block 30, to adapt its position to the movements of dasherrod 37 attached to the end of swinging-arm 64 by means of the crank-pin 38. The inward. movement of dasher 37, shown with dotted lines in dash-pot 36, is retarded or accelerated by means of the screw pinvalves 32, by which the air ports near the bottom of said dash-pot may be gradually opened or closed. The adjusting of these. valves, therefore. determines the number of hammer-strokes per minute delivered in operation; for swinging arm 64, hinged at, pintle (36 and impelled downward by spring (36. can move downward only as fast as dash-pot 36 wilLallow it, being attached to dasheurod 37 at crank-pin 38: now, arm 34 is also engaged to tappetrod 72 loosely hut securely by means of the hinge-stud 67 fixed in arm (34 and passing through a hole larger than itself in tappet-rod 72. so that said arm and rod move up and down together. P But tappet-rod 72 must complete its cycld of movement for every stroke of the hanhner after the first one: consequently. if arm 64. under control of dashpot 36. can make but nine cycles a minute then the hammer will make but nine strokes in the same time. But when the valves 32 are set open wide enough. for arm 64 to complete ninehundredeyeles, more or less per minute, then the hammer will deliver mne hundred strokes more or less, per minute, as set forth in the'stated objects of my invention. i

The hole in tappet-rod ,72 where hingestud 6,7 asses through is made larger than saldjtu' to compensate the are described by Stlld'fi7 in its operative movement on pintle 6 6, while tappet-rod 72, in its normal operation, must move in a straight line.

Arm 64 is double, one part gassing on the hither side of rod 72 and t e other part assm on the yonder side, as illustrated in 1g. I The two parts are held securely together b means of pintle 66, crank-pin 38, hinge-stir 67 andstay-pin 64", against which one end ofsprin 66 coiled around pintle 66, ushes,,while t e other end of said spring is raced against post 35', as shown in Figs. III. and IV. Spring 66 is strong enough to foifce tappet-rod 72 inward to its limitof operation, against the resistance of dash-pot, friction and spri L 56 which must be overcome in the inwa-movement of tappet rod 72 as disk 7Q mo down against m et 53;

appet-rod 72 in the inner end has a deep central boring with internal threads into which is screwed a lon threaded rod 72 close-fitting in the threa s and adapted to be set with more or less of its end standing out of said boring in rod 72, as illustrated in Fig. II. This threaded internal rod 72" is adapted to act as an auxiliary of rod 72 for controlling the length, and consequently the force, of the hammer strokes within their normal limits, as I will duly explain in detail. This feature I have previously mentioned as one of the objects of my invention.

, The three square posts 35, 35 and 35, as I have previously said, are provided at their inner ends with threaded axial lugs which screw into block 30, but at their outer ends they have axial borings threaded. Now the three round posts, each designated 41, monuted on disk 39 directly over the square posts 35, 35 and 35*, are provided at their inner ends with threaded axial lugs which pass loosely through perforations in said d'sk properly located with respect to the 6 Laeagaso through when cap 3 is being removed or re placed on casing 2.

In the inside of cap 3, in the central por-- tion through which passes push-pin idis the set-sorew 3 adapted to be screwed in against push-pin I to hold said pin fast in any de sirahle position. that is, with the switch 47-48 open or closed; shown in Fig, III.

In Fig. VII]. the stone-cutting tool 75 is shown in full side elevation apart from the hammer. The cutting end 75 is sharpened with converging hevels. The round shank 75 is adapted to fit. loosel into the channel 9 of tool-cap J. Figs. VII. and X., as far as the square shoulder-rim 75 which is adapted to stop said tool against the outer end of tool-cap 9, Fig. VII.

In Fig. X. tool 75 is shown entering channel 9 of cap 9 as far as hammerhead 29, which has in the counterhore of chase] 9 ample room to work efficiently.

In Fig. II. may heusee a full longitudinal section. in elevation, o. my solenoid spool and coil assembled and fitted into its place in the casing of the magnet ready for operation. There are shown its hollow spoolcylinder 23, its insulating spool- heads 21 and 22. its coil of insulated wire 19, of which one terminal 19 leads from coil 19, also Fig. III. through spool-head 22 into metal terminal-plate 24 to which the end of 19 is soldered; while the other terminal 19 of said coil is shown in the right side of Figs. II. and III. leading from coil 19 through the outer edge of spool-head 22 into metal terminal-plate 24 to the outer edge of which the terminal 19 'is soldered. The terminal plates 2% and 24 may be seen in Fig. XII. a sidecievation, and Fig. XI. :1 vertical projection of terminal spothcad 22, showing terminal- plates 24 and 24 fastoned to insulating spool head 22 by means of the four clamps 24; In Fig. XI. is also shown the end sections of terminals 19 and 19 as soldered in the plates 24- and 2st respectively.

In Figs. II. and III. is also shown a sectional View of the annular ridge on the inner side of head-cap 5, which is adapted to facilitate the lateral passage of magnetic lines between armature-block 18 and headcap 5. On the inner side of cap 5 between said annular ridge and the edge of the threaded portion of said head-cap fitted the insulating washer 26 clamped to cap 5 by means of screws 28 and 73 in Fig. II. and. by screws 25" in Fig. XIII where washer 26 is shown in a vertical projection; On washer 26 are mounted the insulated contact-sprin 25, with screws 25, and the non-insulated contact-spring 27, held by screws 73 passing through washer 26 into head-cap 5, as shown in Figs. II. and XIII. Screws 73 are adapted to conduct the electric current between OOIltilCt-SPIIIUf 27 and the ground oi the hammer, so that said electric current may run through cap 5 and other metal parts of said hammer to the arm 54- and switchicrminai 53 of the switch 52-53.M'here it passes through at predetermined intervals under automatic control in the normal operation of the hammer, will be explained hereafter.

In assenihiing my clectroanagnet we screw headcap 5 into the head-end of casing 1; then coil 19 on its spool should be pushed head-first into casing 1 in such a way that .spaces 26 hetween the terminal-plates 2i and 21, Fig. XII. shall coincide with insulating blocks 26. Fig. XIII. and cont-acisprings and 27 shall fall on contact plates 24 and 2-1 respectively where good elcctrical contact with, said plates is made with the sharp points 25 of spring 25 and 27 of spring 27. When the solenoid coil is thus seated with block 18 inside of spool-cylinder 23, as illustrated in Fig. II, tailcap 6 with its contiguous parts, armature hammen neck. spring. etc, all assembled, should be screwed into the tail-end of easing 1 tightly. This operation will close the joint between cap 6 and casing 11, and also set the sharp points 25 and 27 of the contact-springs and 27 hard against contact- plates 24 and 2% respectively, so that the electric current passes between. said contact parts readily regardless of vibrations in the hammer. The other mechanism and cases are easily as seinhied.

One oi the insulated conductors I2 of the operative wire of the hammer terminates in binding-post 4:5, and is easily attached or detached at this point; the other conductor 43 has a terminus in binding-post 43*. where connection is made with its inner insulated splice which runs down through perform tions in disk 39, block 30, cup 5. washer 2G and contact-spring in which it is pern'ianently soldered. Figs. III. and XII. I will now describe the operation of m electrical hammer. Fig. I. as I said, rcpt-l, sents a side elevation of the hammer assem- ...hlcd ready for operation. Through the port 2% in (using 2 near cap 3. issue the. electric conductors M3 from the hammer-terminals within. see Fig. IL, out to connect with wires running to the source of the electric current. In practice. a short, flexible, double conductor terminating in a. suitable coupiing-plug, is so attached to each hammer for convenience in comiecting to the current.

Now when the coimections to the current are made and the hammer is held in position on the work. we pr'ss inward on pushpin 4 which forces arm 46 down closing manual switch 47AS. If now, for convenience of explanation, we suppose that the current is running in on conductor 42, and out on con doctor 43, we may'say that, at the closing of switch ill-4.8. the current runs down for Ininal 48 through insulated switch-post,51 and on through the automatic switch terminals 52 and 53 and down along parts 54 and 55 to the egeneral ground of the hammer, whence it runs throu h screw 73, contactspring 27 and termina -plate 24, from which it passes through the terminal 19 and then circulates all through insulated coil 19, Figs. 11. and 111.; and leaving coil 19 through terminal 19, Fig. 111., It passes through terminal plate 24 and insulated contactspring 25 to conductor 43 and thence out to its line again, having completed efiiciently its predetermined circuit of the hammer.

But in Fig. V. a. different course in the energizing current of the solenoid is shown. And Fl V., as 1 have previously said, is design to illustrate how all the conductors of the electric current for the solenoid are insulated from the ound of the hammer, a feature that would desirable under some conditions of work. In Fig. 17., therefore, the side of the line indicated as conductor 43 takes the same course as it takes in the other Figs. 11., 111. and 1V.; and the side of current represented in line 42, follows the ame course as in the other Figs. 11., III. ind IV., from binding post 45 through arm 6, switch 4748, switch-post 51, switch 52-53 to flexible arm 54; but from arm 51, instead of running to the ground of the hammet as shown in the other figures, from arm 54 the current, as illustrated in Fig. 17., takes a new course into loop 42 formed on the and of flexible arm 42 which passes through a perforation in disk 39 to bmdingpost 42 fixed in the insulating block 4:1 fastened to post 41 with screws 41. From binding post 42 the current flows through insulated wire 42' leading down through a straight channel drilled through block 30, cap 5 and insulating washer 26, where it is soldered into contact-spring 27, which in this construction is insulated from the ground of the hammer, having no screws 73 passing through it to connect it electrical] with the ground of the hammer. In Fig. washer 26 is held in place by screws 28 and 7 3 all insulated from the contact- springs 25 and 27. In Fig. V. is also shown the insulating-block 55 fastened to the upper portion of segment 55 with the rivets 55. 1n alongitudinal slot at the 111336! end of insulating block 55 the lower en of the flexible arm 54 is fastened with the rivets 55. Therefore, in the hammer construction shown in Fig. V., as I have said above, the operative electric current of the solenoid never reaches the ground of the hammer.

' through which slides loosely tappet-rod ture-bloek 18, and, under certain conditions, would clash against said block with great force. But this clash is prevented by two things, the spring 11 and the controlling function of tappet-rod 72, as 1 will shortly explain. When armature 16 under magnetic impulse asses inward, taking the hammer part wit it, spring 11, with its inner end abutting block 12 and its outer end braced against the rim of the inner side of hammerhead 29, is gradually set back under increasing tension, as head 29 a proaches'block 12, until just before nose 1 comes in contact with block 18, the spirals of helical spring 11 are crowded together into contact with one another forming a practically solid resistant cylinder between block 12 and the approaching head 29, so that further movement ,of armature 16 inward is completely estopped, spring 11 having been adapted in size of wire and number of spirals so to stop the inward movement of armature 16 at a predetermined place in its operation. While the outward plunge of armature 16 in.uormal operation, is of course sto ped by the direct impact of the hammeread 29 upon the work. Consequently, although my electrical hammer strikes nearly a thousand powerful blows a minute, no concussion takes place within the limits of the magnetic field, an important feature listed as one of the objects of my invention.

In connection with this subject, it might not be out of place here to explain that spring 11 is so graduated in strength that nearly all the energy of the inward impulse of armature 16 is consumed in setting back spring 11 to its niaximum tension for work,

so that there is left very little surplus energy of the inward-moving armature 16 to be counteracted by the resistant spirals of spring 11 crowded together, as above explained.

The other way of limiting the inward movement of armature 16 by means of the controlling function of tappetrod 72, mentioned above, is efl'ected by allowing the inner end of rod 72 to stand through block 18 down into air-gap 17 far enough for inward-plunging nose 17 to strike it and push it outward to cut the electric current from the solenoid, a fact which instantly destroys the magnetism then acting on armature 16 and allows it to plunge outward again under the impulse of spring 11, as I will now explain in detail.

When the solenoid is energized by the circulating current, armature 16, as 1 have said above, plunges inward across air-gap 17" forcing the air out through channel g2 and near the upper end of air-gap 17 the gether with its co-acting parts, as illustrated in Fig. IV. Now, tappet hlock 71, with its tappct-disks 60 and'70 all rigidly fastened to rod.72, leaps upward with said rod, moving tappet 31 for enough to disengage detent 60 from notch 59.- and segment 55 under pressure of spring 56 rocks backward and so opens switch 52-53, thus cutting automatically the current to the solenoid coil and allowing said armature to fly outward again under the recoil of spring 1.1 as I have previously described. This sudden withdrawal of nose 1'? from its pressure on the end of rod 72, allows said rod to move again inwardly under the pressure of spring 66'' and the control of dash'pot 36, as previously described, until tappet disk 70 reaches tappet 58, a rigid part of switchsegment 55 and thus rocks said segment inward again, Fig. III, until switch 52-53 is closed and notch 59 has been carried far enough for detent G0 to snap into it and so lock switch terminals 52 and 53 together again where they will remain in contact passing the current through the solenoid coil again till armature 16 magnetized again pldiiges inward and pushes tappetrod 72 upward again to cut the current at the switch 52-53 as before. In this Way my electrical hammer normally operates automatically with very strong and very rapid strokes, so long as the current is ad mitted to the hammer terminals 4-5 and 43 and the manual switch is held closed.

It can now be readily seen that tappetrod 72 in normal operation is driven upward suddenly with great force at every inward plunge of armature 16. and that the inertia and other resistance of the dasher 37 and continguous parts would throw much stress and Work upon hinge-stud (57 through the enlarged hole in rod 72. For this reason I have made the sleeve 68, a long rigid part of block 71, long enough to reach up to the rounded part 64 of the arm 46, where sleeve 68, is adapted to take all the stress of suddenly lifting arm 64 and its attachments at the upward plunge of armature 16 and rod 72. The lower side of the part 64 has been rounded to rock easily on the upper edge of sleeve 68.

An explanation of the functions of threaded rod? 72 can now be readily under stood from the previous detailed descrip tion of the functions of tappet-rod 72. Rod 72, when made. should be adapted to stand down in the air-gap 17* about far enough to allow the armature 16 to make a complete stroke by the time rod 72 and its disk 69 is pushed up high enough to cut the current from the solenoid. Then when rod 72 is screwed into rod 7 2 nearly flush with its lower end, plunging armature 16 will in operation make a complete movement inward and spring 11 will be set to its n1aximum tension and so in recoil will deliver a of its full stroke. By adjusting the lower end of the threaded rod 72. therefore, so; that it will stand out of rod 72 at a greater or less distance from the end of nose 17, we shall get a correspondingly greater or less blow from the hammer in operation, as I have previously set out in the statement of the objects of my invention.

Another stated object of my present invention is to provide means for dissipating the heat units generated in the solenoid magnet, so that the hammer may operate continuously at a desirable'temperature. This is eflected by makin the solenoid coil ion and comparatively t in to allow a suitab a external surface for radiation, and by forcing a change of air in the internal air-gap 17 through the perfoFation 72 at every stroke of the hammer, and by giving the magnet a heavy iron armature 16 and armature block 18 with heavy iron end- caps 5 and 6, adapted to afford ready convection of internal heat.

It can now also. be readily seen that solenoid coil 19 and its essential parts, 21, 22, 23. '24; and 24, being all securely and permanently fastened together in tine strong package, can be readily removed from the casing of the magnet, so that another coil for a different voltage may be quickly adjusted in its place.

In closing this specification I would direct attention to the new and useful construction and the peculiar operation of my automatic switch 52 53-54, which'opens and closes nearl a thousand times a minute while the hanmier is operating.

Now in the case of a direct-current and cleerie-magnet. it is well known that when the electric circuit is broken, an electric spark springs out from the one terminul of the severed conductor, tending to form an electric arc across to the other terminal of the break. This so-called induction spark at the opening of an electric switch cannot well be entirely eliminated or avoided by any switch mechanism at present generally known. and the spark is detrinicnlul to the switch, in that it heats and burns away the tcnuinals. Consequently, by much experimenting, I have devised and invented an electric switch mechanism 5253-5l. Fig. XV, which in normal operation works with practically cool terminals and slow erosion. This result I have accom lished in part by making the contactend 0 the fixed terminal 52, Figs. III. and XV., of such a shape thatthe contact part 52 would present a comparatively large surface for contactinstead of a single point. so that successive contacts might he made on it in a multiplicity of places promiscuously over the broad surface of the contact part 52; and by making the contact-end of the movable terminal 53 deeply concaved or cup-shapcd so that the contacting part 53 of this terminalshould also be a comparatively broad area instead of a single point for contact with terminal 5:2.

Now by devising a unique attachment feature in connecting terminal 53 to the flexible and oscillating arm 54 Fig. XV., so that terminal 53 rocks freely To every point of its equatorial circumference. I have completed my device for distributing the successive electrical contacts indiscriminately around over the broad surfaces 52 and 53?, so, that in the normal operation of the switch, the induction sparks may "spring out successively from a multiplicity of points, one

after another, over the comparatively broad area of the contact surfaces 52 and 53 instead of s oting out successively from any one point i the terminal, which would cause excemive heat and erosion of the point.

Terminal 52 is of course made of platimm, and is set rigidly and securely into metal block 51. At the contact-end, termiha] 52 is conical and rounded at the extremity; butterminal 53 at its contact-end is rovided with a. cup-like hollow adapted to (5., very loosely on over the conical end of terminal 52. At the outer end of terminal 53, which is also made of platinum, is an axial lug 53*, which after being passed thr h a lateral perforation larger than said u'g in the en of flexible arm 54, is properly headed in such a way as to attach terminal 3 to arm 54 securely but loosel Terminal 3 is thus adapted to'rock slight y in all directions in its joint with arm 54, Now in the normal operation of the hammer, flexible arm 54 oscillates with great rapidity slightly' rocking terminal 53 indiscrimin'atcly in every direction, so that at one stroke the terminals 52 and 53 may make or break their contacts on one side and at the next stroke, on another side, and so on indefinitely seldom striking in the same places twice in succession. And in practice these eculiar switch- terminals 52 and 53 have licen found to be fairly cool and durable in operation. as set out in the stated objects of my invention.

Having thus described the features of my invention. the operation, construction, arrangement and combination of its parts, what I claim in my invention as new and useful and desire to have outlined in Letters an automatic switch for openin and closing said circuit intermittently, com ined with a sliding rod extending longitudinally into the interior of said solenoid and adapted to he pushed outwardly by said plunger spring-pressed devices for ushing said ro into the solenoid a ain, an co-actin mechanism between saim rod and the sai switch adapted to open and close said switch as the sliding rod is pushed alternately in and out of said solenoid.

2. In an electrical hammer of the kind described having a solenoid wound on a hollow spool, a reciprocating armature adapted to slide operatively in said spool and carrying a hammer'portion on its outer end; an electric circuit in said hammer to connect the solenoid for actuating said armature to make its inward stroke. and a driving spring.

on said hammer-portion adapted to force said armature to make its outward stroke; combined with a switch in said circuit; a spring pressed lover; a reciprocating rod attached thereto and extending into said spool and adapted to close said switch when pushed by said lever a predetermined distance into said spool and to open said switch when pushed outward again a predetermined distance by the armature; an axial screw in the inner and of said reciprocating rod adapted to be set partially out of the rod a greater or less distance to give greater or less length opcratively to said rod that the rod may he met earlier or later respectively by the inwardly-moving armature and so pushed outward its predetermined distance to open said switch earlier or later in the Stroke to make a correspondingly lighter or heavier hammer-stroke in normal operation.

In an electrical hammer having a solenoid wound on a hollow spool. a reciprocal:- ing armature adapted to slide operativcly in said spool and carrying a hammer-portion on its outer end; an electric circuit in said hammer to connect the solenoid for actuating said armature to make its inward stroke. and a driving spring on said hammcrp0rti0n adapted to force said armature to make its-outward stroke: combined with a switch in said circuit: a spring pressed lever: a reciprocating rod attached thereto and extending into said spool and ,a'dapted to close said switch when pushed by said lover a predetermined distance into said spool and to open said switch when pushed outward again a predetermined distanclz by the armature; an axial screw in the inner and of bait] reiripirocuting rod adapted to be 501'. purtiuiiy out of the: rod 11 greater m loss dial-mire to give greater u! 10% limgth uperulively to snial rod that the mil may be met earlier or later ruspectiwiy by the inxun'iilymiming armature and s1: pushed nutwnn! it 1HUiitjiifHlllillCli rifihm etn upon mid swih'ii earlier 01' later in Hit stroke to mute a vm'rvspomlingly liginvr Hi heavier il-Hillllv1- f!ui{9 in HUHUHI npvrutiun: mid a Liilldl-PUF attained in mid apringmrw-scd lever and pmviflrd with adjustable \ahes to control the inward movement of said reciprocating rod, a movement which determines the frequency of the hummer-stroke in normal operation, as described.

Tn testimony whereof, I have hereunto set my signature in the presence of two witmesses.

JOHN J. ROIH'JRTS.

Witnesses 7 ALEXANDER C. Scum: ax, GEORGE E. Scum mm.

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