US2806461A - Baseball pitching apparatus - Google Patents

Description

SCP- 17, 1957 P. s. GlovAGNoLl 2,806,461

BASEBALL PITCHING APPARATUS Filed Oct. 2l, 1955 BY [//j 177 Z, /2 4 /WTOANE United States Patent O BASEBALL PITCHING APPARATUS Paul S. Giovagnoli, Kansas City, Mo.

Application October 21, 1955, Serial No. 541,959

7 Claims. (Cl. 124-7) This invention relates to the eld of sporting goods apparatus and, more particularly, to an improved machine for throwing or pitching baseballs or the like.

Baseball teams have long found it a nuisance to re quire human pitchers to throw practice balls to the other players during the batting practice or the warm up period prior to a game.

Accordingly, it is one of the important objects of this invention to provide a machine adapted for automatically and reliably pitching baseballs to a batter during practice or the like in fashion closely simulating the manner in which a baseball would be pitched by a human thrower.

It has also been found that many persons not regularly engaged in playing baseball enjoy attempting to bat baseballs thrown in a manner simulating that in which they would be pitched during a baseball game as an amusement or recreational activity. To provide for such healthful recreation, concessions or stands somewhat similar to golf practice driving ranges, have been established. The factors of cost and safety have, however, rendered the use of human pitchers at such concessions disadvantageous if not entirely impractical.

It is, therefore, another important object of this invention to provide baseball pitching apparatus adapted for use at such recreational facilities.

It is another important object of this invention to provide baseball pitching apparatus which will automatically and successively throw a plurality of baseballs in predetermined fashion and at preselected time intervals.

It is another important object of the invention to provide such apparatus which includes improved counting means adapting the apparatus for automatically deactivating itself after pitching a predetermined number of baseballs.

It is another important object of this invention to provide improved, mechanical, throwing hand structure including a sponge rubber ball-carrying pad adapted to release a baseball in fashion causing the latter to follow a trajectory equivalent to that of a baseball when thrown by a professional human pitcher, which trajectory is substantially uniform for every ball thrown despite wetness, softness, tears or other irregularities in the condition of the balls.

It is another important object of this invention to provide means for successively feeding baseballs to the throwing arm portion of the apparatus in manner assuring a continuous iiow thereof without jamming.

It is still another important object of this invention to provide such apparatus which is of simple nature minimizing initial manufacturing costs, necessity for maintenance, difficulty in installation and malfunctions during operation.

Many other important objects of this invention, including certain important details of construction, will be made clear or become apparent as the following description of the invention progresses.

Patented Sept. 17, 1957 ICC In the accompanying drawing:

Figure 1 is a perspective view of a baseball pitching machine made in accordance with this invention taken from slightly above and to one side of the apparatus.

Fig. 2 is a side sectional view of the machine taken from the opposite side of the apparatus.

Fig. 3 is a fragmentary, cross-sectional view taken on line III- III of Fig. l.

Fig. 4 is a fragmentary, cross-sectional view taken on line IV-IV of Fig. 2.

Fig. 5 is a cross-sectional view taken through the throwing hand assembly per se; and

Fig. 6 is an enlarged, fragmentary, side elevational view particularly showing the counting means employed for accomplishing automatic shut-off of the machine after a predetermined number of baseballs have been thrown thereby.

Referring now to the accompanying drawing, the numeral 10 generally designates a base assembly forming a part of the contemplated machine. In the illustrated embodiment, base assembly 10 includes a T- shaped, ground-engaging member 12 having a cross part 14, an upright post 16 rigidly mounted upon member 12, a vertical plate 18 rigidly secured to the uppermost extremity of post 16, a laterally-extending element 20 slightly above, but adjacent the member 12, an oppositely-extending lateral element 22 upon post 16 and spaced above the zone of juncture of element 20 with post 16, a rearwardly-extending element 24 on post 16, a diagonal bracing element 26 interconnecting element 24 and the upper extremity of post 16, and a spacing and fastening element 28 interconnecting element 24 with member 12 in spaced relation to post 16.

As will be apparent from the drawing, each of the parts of base assembly 10 except plate 18 and element 28 (which is preferably adjustable) may be constructed of metal pipe welded or otherwise suitably interconnected to present a rigid base assembly adapted for mounting the other structure hereinafter to be identified and described.

A baseball-receiving receptacle, generally designated 30, is rigidly mounted upon the base assembly 10 in any suitable manner as by clamps 32 and 34 upon element 22 of base assembly 10 and a clamp 36 attached to post 16 adjacent the uppermost end of the latter.

Receptacle includes an open top cage 38 which may be of wire mesh side and end wall construction. Cage 38 is provided with a bottom wall comprised of three side-by-sde elongated sections 40, 42 and 44, section 42 being disposed between sections 40 and 44. Sections and 44 are rigidly mounted as a stationary part of the cage 38 by any suitable fastening means such as at 46. The proximate edges 48 and 50 of sections 40 and 44 are disposed in spaced parallelism and are lower than the remote edges 52 and 54 of sections 40 and 44 respectively. In other words, sections 40 and 44 slope downwardly as their proximate edges 48 and are approached. Sections 40 and 44 are also so disposed within cage 38 that the ends 56 and 58 respectively thereof adjacent the post 16 are lower than the ends and 62 thereof remote from post 16, whereby the sections 40 and 44 slope downwardly toward the post 16, as well as downwardly as their adjacent edges 48 and 50 are approached.

The section 42 is pivotally mounted adjacent one end thereof by hinge means 64 mounted upon a lower frame portion 66 of cage 38. Section 42 extends between edges 48 and 50 of sections 40 and 44 respectively and is adapted to swing about hinge 64 through an arc extending above and below the plane of edges 48 and 50.

An elongated member 68 is also pivoted upon cage 38 by hinge means 64 and extends downwardly from the latter -l-toward-x post -16. An-interconnecting element -70 rigidly secured to the top of member 68 and the bottom of section 42 attaches the section 42 to member`68 for swinging with the latter.- Y

llieacgige38 `is -provided with a; evertical out-let opening as at 72,--wh-ioh isieoveredfby-a'-veticallydisposedseniitubularaportion'f^74lexternalto -cage 38 ,off -ab'alljca ying -tube generally designated "7 6 and also -including aight angle bend portion =78arid-aE downwardly-slopingfpdiitin .80.terminating-in -an-open-end'i382. lfhe extrem-ity of bottom section 42 of receptacle 30 adjacent-opening -72 `is concavely .cutawayz-asa 84Ltoper'n`1it-l thepassage of a baseball into portion 74 of carrying;,tubez` 76 'and down- ;wardlypast extremity-'.84 into-'portionS andthence-portion 80 of the carryingtubee76. i i i v f i sA; downwardly .slopingLchannelmember :ismounted .tuRQI1.f.element 20 :and hasits ,uppermost 'extremityl dis- .posed :beneath .the .openendaSZ .of carrying tube 176 to .gneceivegbaseballsreS emerging-'fromlthehlatter `and carry same Vtoward a stop element 90 mountedupondbasefelement2-D. .--Itisjlsigniiiclant .that .the stopi90iis spaced lfrom thelowermosnextremityZ.offchannel 186 a distanceY suffllnttt@ Lflar,.Strtlcturehereinafterztonbe described, Abut IJSQQQH t0.: pCLmiLaabaSeball @88 .to rdropihetween-.the channelf and-the stopg9g0. yWhenonebaseball-88. is disposedfin oppositecnggernent Vw,iththestop 90 and the Vvlowerrnost.-fextremity 39,2of .channel 18.6,'. the other bvraseballsS E.willbe Ylieldinposition uponV channel. 86 and within carrying tube@das-bestgillustratd in'Fig. 3.

AVTlotatablye.,.mounted `upon,p,l ate 18 is a horizontal ,shaft V94 having a sprocket k.wheelflxrigidly, securedzthereon. Secured to plate .18by .meanspf abracketg-Sandsuit- .ablefasteningfmeans `100'is an electric` motor; 1,02,A which ,is coupled bt/,gaben 1,04iw4ifhfthenrst of aseriesef reduction 2*gears 19.6,.108nd -1;1..0 .rotatably Vsupprted .upon plate 18, the last gear .llobeingruponga shaft-112 extend- `ing .through plate 18 and having a dveqsprocketlM mounted ,thereon on l.thesside .of plate 18,-l oppositeV motor 102. Y ,Drive's'procket t11 4 is operably:coupled by. a chain `1.16Nwith sprocket wheel9 6,'on yshaft 9,4, chain tightening meansas Vat 1-1 8 preferably being provided.

elongated piek-'riparm 12,0 is adjustablyybut rigidly, mounted adjacent one end thereof upon sprocket `wheel ,9 6 bytfvasteningmeans v122 iand ,124. Adjustablymounted vbyfastening,means ',12`6`uponlthe extremity, pt arm' V120 remotefromsprocket wheel is. a, baseb allpicktipY device broadlyrzdesignated 1.28, which includes La.rstelQngated, rigid loop 130 preferably ,-.foiiriedbf ,heavy wire :rod and .3. Second` elongated. loop ,132'. wl1iclil curves fromhe. portion ,thereoi adjacent loop 130 .fron .a generally perpend icular `.rnlatiduship .between loops' ..130 l,and 13 2 .to a generallyiparallel l.relationship as the: eXtlQmity of .loop 13 2 remote froimiloop,130,isiapproached. .'Ihe,1oop130 in jcludes a A, narrow, laterally'v bentportion 134,adabted to pass between the'lowen .QXtremity' 92 f channel' 36', and the. stop.9 0. Suitable bi'` cing.structure,.designated `-136 ispprovidedgtorimou gv the` loopsm130gand ,.-132. upon arr`n 120 and'jfor retaining same in their desired .relative dispositions.

` Although the` operation .ofzthe devicewillbehereinafter more fully described, Vit `should now. be understood that theloop 130.is adapted to pass under, a ball 88` resting between stop y90 and extremity 92 of channelf86 with'loop portion134 passingbetween.stopf.9 0 andextr'ernity92sov thata b all 88 is picked up^on31oop-130 each ntime vthe sprocket wheel96 is rotated through that portion of its arc swinging arm 120to Yrnoyeloc'gp portion 134 between stop .9,0 and e; t r e rnityV 92. i'

fRotatably mounted upon the` shaft .94 is, Tamelongated throwing arm 138 having anangularlyextending.crank extension 140 atwthe end thereof mounted, upnrr,y shaft' 94 a 'throwing hand .assembly generally designated-142 upon the opposite end thereof.v i i Y 4 preferably adjustably mounted upon arm 138 by slot and fasteningV means 144 or-othersuitable structure. The throwing hand assembly 142 is formed of a crossesectionally T-shaped, elongated element 146 having a concavely faced crosspiece 148 upon which is secured a ball-engaging pad 150 of sponge rubber or other similar resilient material. The outermost face 152 of pad 150 is concavely curved transversely thereof and, as will be clear in Figs. ll and 2, the outermostelndof arm 13.8 extends beyond the plane of face 4152 so that a ball 88 may be reliably supported ,upon thehand assembly `142 by virtue of the curvaturegof f ace 152 and the engagement of the ballSS withthe free end of arm 13S. It will also be observed that the Ythrowing hand assembly 142 is of dimension adapted to freely pass between the sides of loop 132 of pick-up assembly 128.

The provision of pad 150 of the particular material and form mentioned is extremely significant. alh'ard, smooth or less resilient material 'isusfe'd `for padilntl, cuts, wetness,V softness and other irregularities arej'fo'und t 't'. a very material eiect lon the point ofrelease of balls-88 from face 152y and, therefore, lthe balls tfrajectorie's.` However, with the pad 150 made of sppnrgeirubb'er, Ythe principal resistance to departure ofl ay ball8`8 fromfface Y.1j5`2`is provided by the nature of pad150a`n'd itsufacej l l the elte'cts of'irre'g'ula'rit'ies'in-the `balls:88are`-nfl-i to a point of -substantialelimination.V

A laterally exte'ndingpin154 rigidly mounted upon sprocket wheel'96gis 'adapted to'engage the'armi138 adjacent the end ofthe latter `mounted upon shaitx94`for swinging the armV 138 througha portion'of its yarci'of rotation. VVIt issigniicant thatfthepinV 154 -is so disposed that whenarm 138 is in engagementth'erewith, the throwing -hand assembly 142-isdisp'sed within theloopf132aslillustratedin Figs. l and 2.

Astrong metallioleaf spring 156-in-the general'lshape of a0, is rigidly attached at its lowermost'end to thefbase elementiZ) and `has a Vrod 158 rigidlyrsecured toits opposite end and vextending laterallyltherefrotn AV iiexible, preferably metallic cableY 1.60,is adjustablycoupledwith the .crank extensionh140 by fastening Arn'ean's"V 1,62Y within .a .slot 164 .of extension lfiiland with rod-158by adjustable retaining means `v1.66.

A crank 168 is provided upon shaft' 94 and-rigidlyattachedthereto on the same side Yof plate 18' as motor 102.

-Alink 1.70 is .pivotallyconnected as at 1"/'2` with crank 168 and pivotally connectedl as at 174 withV the lowerniost extremity of member 68,4itbein`gY evident that, a's-'shaft`g96 -96 and plate :18 each.` time the sprocket-96 makes vone revoluti911thereby.swinging the rod 178 against the' 'action of springr180 to rock oroscillate theshaft 176.

On the opposite side of plate 18, whichis thesameside las-motor 102 is located on, is provided a pair of onetoothedspr'ockets 184 and 186. -Sprocket `184;,is rigidly mounted on plate 18 with, its singlev tooth.188 extending upwardly. Sprocket 186 is rigidly mounted' on shaft 176 with its single tooth 190 normally exending ,upwardly when the rod1 7:8 is in the position to whichitis normally biased bythe spring 1,80. ATrainedoverYSDISJQIQSS 18 .and 186 is alink chai1r192.v

Itis signicant to Vnote'thatztheconfiguration of each of teeth 188 and 190 of sprockets'184'and1`8'6respectively,

is of saw-tooth form presenting a sloping surface over which the cross elements of chain 192 may advance and with a radial face for engaging such cross elements to hold or move the chain. Y

As will hereinafter be more fully explained, each time the rod 178 is swung by the pin 182, sprocket 186 is oscillated in a clockwise direction as illustrated in Fig. 6 to advance the chain 192 one link. Chain 192 is provided with a predetermined number of links each of which corresponds to one revolution ofthe sprocket Wheel 96. Mounted upon one link 194 of chain 192 is an outwardly extending dog 196 adapted to engage and operate an arm 198 of an electrical control or switching device 200. Device 290 may constitute either an electrical switch adapted to be associated with electrical circuitry (not shown) for giving an indication of when the machine has been operated to throw a predetermined number of balls 88 corresponding to the number of links in chain 192, although it preferably comprises a latching relay associated with coin-operated electrical energizing circuitry (not shown) for motor 182 wherein the deposit of a coin will result in energization of motor 182 and such energization will be continued until the dog 196 has operably engaged arm 198 to unlatch the relay 2119.

ln operation, the machine is actuated by completing an electrical circuit (not shown) to energize motor 102. As just noted, the device 288 will preferably be coupled with such electrical circuit for breaking the same after a predetermined number of balls 88 have been thrown. Energization of motor 102 drives reduction gears 104, 108 and 116 to rotate shaft 112 and drive sprocket 114, which in turn, through chain 116, rotates sprocket wheel 96 at a predetermined, relatively low speed. The throwvn ing arm 138 will, until it is engaged by the pin 154 on sprocket wheel 96, normally be disposed with its longitudinal axis approximately horizontal or at three oclock as illustrated in Fig. 1 by virtue of the pulling action of spring 156 upon cable 168 and extension 140.

As the sprocket wheel 96 is rotated to a position bringing pin 154 in engagement with throwing arm 138, the pick-up arm 121) will move into the position relative to throwing arm 138 illustrated in Figs. l and 2. As the motor 102 continues the rotation of sprocket wheel 96, the pick-up arm 121B and throwing arm 138 will rotate together in such relative position downwardly toward the lowermost portion of their arcs of rotation, it being noted that rotation of the throwing arm 138 is necessarily attended by a yielding of spring 156 as extension 140 is rotated to exert an increased pull upon cable 168.

As arms 12@ and 138 approach their lowermost positions of rotation, the loop 130 passes under the ball supported between stop 98 and channel extremity 92 and, as the rotation continues, the loop portion 134 passes between stop 9i) and channel extremity 92 picking up a single ball 88 upon the loop 13G. As the arms further continue -their rotation to a position approaching seven oclock, as illustrated in Fig. l, the ball 88 picked up on loop 138 will move by gravity toward `the zone of juncture of loops 138 and 132, and will eventually move onto the loop 132 as the rotation is continued to an eight oclock position.

With the rotation continuing, as the arms and 138 approach a nine oclock position, the ball 88 on loop 132 will roll by gravity onto t-he throwing hand assembly 142 of throwing arm 138, which is then extending between the sides of loop 1.32.

After the ball 88 has been moved by gravity onto the throwing hand assembly 142, the throwing arm 13S will be approaching a position moving the extension 148 toward a past center position with respect to the axis of rotation provided by shaft 94 and the interconnection with spring 156 provided by cable 160.

1t should be observed that the connection of cable 168 with extension 148 etfected by means 162, is pivotal. When the centered position in which cable 168 intersects 6 the axis of shaft 94 is passed, the force stored in spring 156 and coupled with throwing arm 138 through cable and extension 140, will take over and acceleratingly rotate the throwing arm 138 upon shaft 94 ahead of the movement of pin 154 and sprocket 96, through a portion of the arc of rotation of arm 138, approximately commencing at the nine oclock position and ending at the lthree oclock position, as illustrated in Fig. l.

The ball 88 upon throwing hand assembly 142 will be thrown from the latter yduring this accelerated rotation olf `arm 138 under the inuence of spring 156, the ball 88 normally leaving the assembly 142 when the throwing arm 138 is disposed approximately at a twelve oclock position. The throwing arm 138 will then be held at its three oclock position by the action of spring 156 until the sprocket wheel 96 has continued its rotation to a point again bringing pin 154 into engagement with arm 138.

During such throwing of the first ball 88, another ball 88 will have moved into ready position between the stop 90 and the channel extremity 92, and the pin 182 will have oscillated rod 178 to rotate the sprocket 186 through an arc equivalent to the length `of one link of chain 192. After the pin 182 has released rod 178, the cross element of the next link of chain 192 will have been advanced over tooth 188 of stationary sprocket 184 and sprocket 186 will have been released for counter- `clockwise rotation (as illustrated in Fig. 6) so that tooth 190 thereof will have slid under and engaged the cross element of the corresponding next link adjacent thereto. It is significant that the sprockets 184 and 186 are so formed as to retain the chain 192 thereon while the 'latter is being advanced over the teeth 188 and 190.

Also during the throwing of the first ball 88, the crank 168 upon shaft 94, will have reciprocated the link 170 to swing the member 68 sand the cage bottom section 42 about the axis of hinge 64. Such swinging movement of bottom section 42 will jostle the balls remaining within cage 38 to prevent jamming thereof and assure their continued successive flow into the ball-carrying means 76 through the outlet opening 72.

Such operating cycle of the machine is repeated until the dog 196 upon chain 192 has been moved to a position operating arm 198 of control device 281), whereupon Ia predetermined number of balls 88 corresponding to the number of links in chain 192 will have been thrown, and the device 200 will operate to make an indication of such fact, or preferably, will interrupt energizing circuitry (not shown) for motor 102.

It will now be clear that the machine contemplated by this invention is advantageous in many ways over any apparatus known to have lbeen previously proposed for such purpose. It will also be evident that the machine is ideally :suited for accomplishing all of the abovementioned and other objectives `of the invention.

Manifestly, however, many minor changes and modiications could be made from the exact construction disclosed for purposes 'of illustration without departing from the true spirit or intention of the invention.

Accordingly, it is to be understood that the invention shall be deemed limited only by the scope of the appended claims.

Having thus described the invention what is claimed as new and desired to be secured by Letters Patent is:

l. In a machine for throwing baseballs, a base assembly; a shaft mounted on the assembly for rotation about a substantially horizontal axis; a prime mover on the assembly; means operably coupling the prime mover with the shaft for rotation of the latter; an elongated throwing arm substantially radial to the shaft and having one end thereof rotatably mounted on the shaft; a throwing hand structure mounted on the opposite end of the arm, said structure being adapted for receiving and supporting a ball until the latter is thrown; a device on the shaft and rotatable therewith, said device being .rleasably engageable with the ahh for rotating .1t-helatterin one direction through a firstpportion of a vcircular Yarc around the shaft; past-center actuating I neohanisrn coupled with the assembly and the arm for acceleratingly rotating the latter through a second portion of said arc; apparatus on `the assembly adapted for delivering a ball to a given location .on the assembly during'the rotation of the arm through said first portion of said arc; and an elongated ball pickup arm, oneendof the pick-up arm heine secured t0 Said device for rotation therewith, there being parts mounted on the opposite end of the pick-up arm adapted to pick up a singleball from said location and deliver the ball to said structure during rotation of the pick-up arm through said first portion of thearc, `said structure being accelerated ahead of the pick-up during rotation thereof through .the Second portion of said arc.

2. In a machine as set forth in claim l, wherein said structure includes -an elongated element adjustably mounted on the arm and having a transversely curved,

,channel-like, concave face, Asaid face extending the entire length of the element, there being a resilient pad secured to and covering said face, thelongitudinal axisof said element being generally radial to said shaft, a portion of the throwing arm extending above the face to support the ball while the latter is disposed on the face during the first portion of said arc.

3. In a machine as YSetforth in claim l, wherein said apparatus Vincludes a ball-receiving receptacle mounted on the assembly and having an outlet therein; means adapted -forgravity feeding balls from said receptacle successively to said given location; and wherein said ball pickup arm is secured to the device adjacent said shaft for rotation therewith, said pick-up arm having ahah-receiving track extending substantially laterally therefrom and adapted topicl up a single b all from saidnlocation and deliver thel same onto said structure during each complete revolution ofthe shaft.

4. In a machine as set forth in claim 3, wherein said receptacle includes a sectioned bottom wall havingy a'pair of substantially horizontal sloppingjouter sections and a central section disposed therebelow, said central section being hingedly mounted for swinging movement relative to said outer sections, and wherein is provided vmeans operably couplingthe central sectionwithY-the shaft for swinging oscillation of ASaid.,Clltral section as the shaft revolves.

5. In a machine as set forth in claim 1, wherein is provided a control mechanism operably coupled with said prime mover for controlling activation and deactivationof the latter, said mechanism being mounted onsaid assembly and having an operating arm, andcounting means mechanically responsive tothenumber of rotations made by said shaft, said counting means having parts adapted for engagement with said operating arm for operatingr'the mechanism to deactivatefthe pmefmover when the shaft has been rotated a predetermined number of times.

6. In a machine as set forth in 4claim 5, wherein said countinglmeans includes a stub shaft rotatably mounted toward a predetermined rotational position; means on said first-mentioned shaft engageable with said radial element .for oscillating `said stub shaft during each revolution of thedirst-mentioned shaft; an endless chain of'predetermined length; said parts of said counting means comprising rneanson said chain adapted to engage the operating Aarnuto.( ieactivate said prime mover upon rotation of the first-mentioned shaft said predetermined number Y of times;-me ans on said assembly shiftably supporting said chain; means operably coupling said stub shaft with said chainpfor advancing the chain a predetermined distance in one direction each time the stub shaft is oscillated; and means operably coupled with the chain for preventing retrograde movement thereof in an opposite direction.

7. In a machine for throwing baseballs, a base assembly; a shaft mounted on the assembly for rotation about a substantially horizontal axis; a prime mover on the assembly; means operably coupling the prime mover with the shaft for rotation of the latter; an elongated throwing arm substantially radial to the shaft and having one end thereof rotatably mounted on the shaft; a throwing hand structure mounted on the opposite end of the arm, said structure being adapted for receiving and supporting aball until the latter is thrown; a device on the shaft and rotatable therewith, said device being releasably engageable with the arm for rotating the latter in one direction through aiirst portion of a circular arc around the yshaft;,pastcenter actuating mechanism coupled with theassembly andthe arm for acceleratingly rotating the latter through 'a second portion of said arc; apparatus on the assembly adapted for delivering a ball to a given location on the assembly during the rotation of the arm through said rst portion of said arc; and an elongated ball pickupV arm, one end ofthe pick-up arm being secured to said device adjacent said shaft for rotation therewith, there being a ball-receiving track adjustably mounted on the oppositeend of the pick-up arm, said track extending substantially laterally from the pick-up arm and including ahrst elongated loop and a second elongated loop, said first loop being substantially perpendicular to the pick-up arm and adapted to pick up a single ball from said location, and the second loop being oblique to said pick-up arm and adapted to deliver the ball to said structure during rotation of the pick-up arm through said rst portion of the arc, said structure being accelerated ahead of the pick-up arm during rotation thereof through the second portion of said arc.

References Cited in the file of this patent UNITED STATES PATENTS 629,044 McGlashan July 18, 1899 1,047,989 Reeves l Dec. 24, 1 912 1,146,262 Judd .Tuly I3, 1915 2,655,908 Callco Oct. 20, 1953 2,696,204 Gilgoif Dec. 7, 1954

Images