US2821935A

US2821935A - Ballast tamper

Info

Publication number: US2821935A
Application number: US285977A
Authority: US
Inventors: Theodore S Bean
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-05-03
Filing date: 1952-05-03
Publication date: 1958-02-04
Anticipated expiration: 1975-02-04

Description

T. S. BEAN BALLAST TAMPER Feb. 4, 195s 10 Sheets-Sheet 1 Filed May 3. 1952 T. S. BEAN BALLAST TAMPER Feb. 4, 1958 10 Sheets-Sheet 2 Filed May 3. 1952 INVENTOR. /fiaaei .5. f4/v irma/vir;

T. S. BEAN BALLAST TAMPER Feb. 4, 195s 1o sheetssheet 3 Filed May 5, 1952 INVENToR. Zwama! 5. f4/v Fla? '1'. s. BEAN 2,821,935

BALLAST TAMPER lO Sheets-Sheet 4 Feb. 4, 1958 Filed May 3, 1952 n Feb. 4r,v 1958 I T. s. BEAN BALLAST TAMPER 1o sheets-sheet 5 Filed May 3. 1952 @i 1 /45 .X5 1k y ,y

f INVENTOR. rIaDapI/i, iiN

inap/vir.;

Feb. 4, 1958l T. s. BEAN 2,821,935

BALLAST TAMPER Filed May' s, 1952 1o sheets-sheet s INVENToR. Imaam! .5. ifi/v 8%@ Mqam.

Armi/w76 Feb. 4, 1958 T. s. BEAN 2,821,935

BALLAST TAMPER Filed May 3. 1952 1o sheets-sheet a 5 /54 JNVENTOA F16. I3 72500455554# Feb. 4, 1958 l T. s@ BEAN 2,821,935

BALLAST TAMPER A Filed May s. 1952 1o sheets-sheet 9 INVENTOR. www 5. mv

` Feb. 4, 1958 '1'.s:BEAN 2,821,935

BALLAST TAMPER Filed May s. `1952 1o sheets-sheet 1o INVENTOR. @www mv fram/fra' United States Patent .BALLAST 'TAMPER Theodore. S. Bean, Oakland, Calif. Application May 3, 1952, Serial No. 285,977

14 Claims. (Cl. .1ML-l2) This invention relates to and in general has for its object the provision of `a tamping machine for tamping the ballast of a railroad bed thereby Itobring its -ties and rails up to proper `line'and grade.

More particularly, the objects of this linvention include the provision of a ballast tamper mounted -on a truck arranged totravel over a railroad 4and including a transversely movable carriage :provided with a pair `oflaterally offset elevators respectively overlyingtone of the rails of the railroad. Secured to each elevator and extending fore and aft thereof is a pair of laterally oifsetarcuate or crowned rails supporting a pair oi longitudinally spaced crossheads, these crossheads being .arranged to be moved toward or away from yeach other thereby to vary their subtended angle. `Mounted on the lower. side or each crosshead for vertical movement relative thereto is avertically reciprocable tamper carrier or .assembly and depending from eachassembly is a pneumatically vibrated tamper arranged to be forced into the ballast beneath 'one of the ties of the road. Associated ywith allot these elements are pneumatically operated pistons Lfor imparting the desired movements thereto, these pistons :being .under the control of suitable valves :some of which are interlocking so as to insure the proper and desired sequence yof operation.

A further and important object of this invention is the provision of a tamper operating assembly of the .general character above described wherein the force for reciprocating the tampers is always applied in a straight Vline along the axis thereof.

The invention possesses lother advantageous features, some of which, with the' foregoing, will be set forth-at length in the following description where that form of the invention which has been selected for illustration inthe drawings accompanying and lforming a partoffthepresent specification, is outlined in full. In said drawings, one form of the invention is shown, but it isto4 be understood that iteis `not limited lto-su`ch lform, since 4the `invention as set forth in the claims may be embodied in other forms.

Referring to the drawings:

Fig. 1 is a side elevation of 4a lballast tamper-embodying the objects of my invention and shownin its 'inoperative position mounted on the rails of a railroad.

Fig. 2 is a rear end elevation of the tamper shownY in Fig. 1 but with the operators seat removed'to betterillustrate its construction.

Fig. 3 is a section on line 3--3 of Fig. 2 showing the machine in its inoperative position.

Fig. 4 is a side elevation of the machine showing vthe machine ready foroperation.

Fig. 5 is a section taken on the section lineS-'S -of Fig. 4.

Fig. 6 is a view similar to. Fig. ishowing the machine in an intermediate stage of operation.

Fig. 7 is a-sectionstaken tonrthefsection rk1ine"-';7.of Fig. 16.

2,821,935 Patented Feb. 4, 1958 Fig. 8 is a section taken on the section line 8-8 `of Fig. 7.

Fig. 9 -is a section 4taken* on the section line 9-9of Fig. 7.

Fig. 10 is-a section taken on the section line 10-10 of Fig. l'showing the llaterally moving carriage positioned on the truck and the truck positioned on the rails of a rail road.

AFig.-11 is afsection taken on the section line 11--11 of Fig. 10 showing one of the pistons for imparting lateral movement to the carriage and 4its linkage between the car riage and the truck.

Fig. 12 isa section taken ron the section line 12--12 of Fig. 2 illustrating the control mechanism for elevating and lowering the elevator and for imparting a lateral movement to the carriage.

Fig. 13 is a section taken on the section line 13-13- of Fig. 12 showing a portion of the control mechanismin its neutral position.

Fig. 14 is a section similar to Fig. `13 but showing the control mechanism in a position to impart to the carriage lateral movement to the right.

Fig. 15 is a View similar to Fig. 13 but showing the control'mecham'sm in a position where left-hand movement is imparted to the carriage.

Fig. 16 is a schematic drawing of the control circuit for the left-hand half of themachine as viewed in Fig. 2, .the cotnrol circuit for the right-hand half of the machine being identical to that illustrated.

Fig. 17 is a schematic drawing of the control circuit for effecting lateral movement of the carriage, the circuit being shown in its neutral position.

Fig. 18 is a schematic drawing similar to that as .shown in Fig. 17 but wherein the control circuit is shown in the position of the carriage when the carriage has been moved to the right as viewed in Fig. 2.

Fig. 19 is a schematic drawing similar to that shown inFig. 17 but wherein the controlmechanism is illustrated iti-the` position wherein the carriage has been placed in itsleft-hand position as viewed in Fig. 2.

GENERAL CONSTRUCTION As illustratedA in `these vvarious V.figures andas already indicated in'setting forth the objects of this invention, my ballast tamper includes `a truck A adapted totravelalong the rails of a railroad under the inuence of any suitable motive-power; a carriage B slidablymounted on Vthe truck Avfor transverse movementthereonin either direction; a pair of elevators C mounted on said carriage for `vertical movementthereon; a pairofopposed tamper crossheads D mounted on -each of the elevators for arcuate movement towards and away from veach other. soas to vary their cant or inclination with respect to the vertical; a tamper assembly E secured to and depending vfrom each of said tamper crossheads; an interlocked control circuit Ffor imparting lateral movement to the carriage \-B .and for raisingzand lowering thetwo elevators C; and a control circuit G for moving said tamper crossheads to vary the cant or inclination of the tamper assemblies and to impart axially reciprocation thereto.

Truck As best `shown in Figs. v1, 2, 4 and l0, the truck A-is of general rectangular form, `.is made of fabricated steel shapes and includes a pair of laterally spaced longitudinally extending H beams l and 2, and a pair of front and rear end-beams 3 and4 interconnected to the

sidebeams

1 and 2 by corner beams 5. `Spanning `the end beams 3 and 4 is a central H, beam 6, the ends .of this Vbeamubeing connected to `thebeams .land 4 by gusset plates7and 8, respectively. VExtending .transversely .of r.the Yframe. so

formed and welded to the side beams 1 and 2 is a central H beam 9, and similarly welded to the

beams

1 and 2 intermediate the transverse beam 9 and the end beams 3 and 4 are transverse H beams 11 and 12. Spanning and welded to the beams 3 and 11 are a pair of laterally spaced, longitudinally extending angle beams 13 and 14 and similarly welded to and between the beams 4 and 12 are longitudinally extending angle beams 15 and 16, these beams and the beamsv 13 and 14 serving as a support for axle bearings 17. Journaled in the laterally opposed pairs of bearings 17 are

axles

18 and 19 and mounted on the ends of these axles are anged wheels 21 arranged to travel on the

rails

22 and 23 of a railroad under repair and for construction. The

rails

22 and 23 are secured in the usual fashion by plates 24 to ties 25, the ties in turn being supported on the ballast 26 of roadbed.

Welded to and over the ends and central portions of the

transverse beams

9, 11 and 12 are inverted

channels

27, 28, 29, 30, 31, 32 and 33, these channels being considerably wider than the beams on which they rest. Bolted to each of these inverted channels is a wear-plate 34 and bolted over these wear-plates and to the channels are laterally spaced guide bar clips 35 best shown in Figs. l, 4 and 6. The clips 35 are undercut, each pair of clips defining a channel or guideway for the reception of slide shoes for supporting the carriage B and which will be presently described.

As indicated in Fig. l, the truck A is arranged to be propelled along the

rails

22 and 23 by an air motor M having a driving connection with the rear axle 19 and under the control of an operating lever L. Although not illustrated, compressed air can be delivered to the motor from a compressed air tank mounted on the truck and communicating with a source of compressed air. Since the motor M and its control mechanism per se form no part of this invention, it is deemed unnecessary to describe their construction and operation in further detail.

Carriage The carriage B like the truck A is of fabricated steel construction and includes a lower rectangular frame comprising a pair of side beams 41 and 42 welded at their ends to opposed, parallel front and rear H beams 43 and 44.

Welded to the beams 41 and 42 midway between the

beams

43 and 44 is a central transverse H beam 45. As will be observed from an inspection of Fig. l0, this lower rectangular carriage frame is arranged to exactly overlie that portion of the truck constituted by the side beams 1 and 2 `and the intermediate transverse beams 11 and 12.

Bolted to each of the ends of the H beams 43, 44 and 45 and to the centers thereof are pairs of opposed angle shaped slide shoes 46 and 47. As shown in Figs. l, 3 and 4, each pair of opposed slide shoes 47 is arranged to slide on their associated wear-plates 34 within the channel formed by the guide bar clips 35. Aflixed to the ends of the

beams

43 and 44 and to intermediate points thereon are two laterally spaced sets of four upstanding

tubular columns

48, 49, 51 and 52, and 53, 54, 55 and 56 (see Figs. 2 and l0). Mounted on and secured to the first set of four

columns

48, 49, 51 and 52 is an upper rectangular fabricated steel frame including opposed side I beams 57 and 58 and front and back I beams 59 and 61. Similarly secured to the other set of the four standing

columns

53, 54, 55 and 56 is an upper rectangular fabricated steel frame generally designated by the reference numeral 62 (see Fig. 2). Connecting the two upper rectangular carriage frames so formed are one or more tie rods 63 extending transversely of the machine as illustrated in Fig. 2.

Mounted centrally over each of the rectangular frames of the carriage B is an overhead ggallows generally des,-

ignated by the reference numeral 64 including opposed uprights 65 and 66 and a crossbeam 67 (Fig. 2). Pivoted to the crossbeam 67 is a hook 68 biased to its closed position by a tension spring 69 secured at one end to the hook 68 and at its other end to the crossbeam 67. Welded to and depending from the crossbeam 67 is a finger or stop 71 for limiting the movement of the hook 68 towards its closed position. Fastened to the hook 68 intermediate its end is a cable 72 reeved around suitable direction changing pulleys 73 and terminating in a hand pull 74 located in a position accessible to the operator of the tamping machine.

Elevators Slidably mounted on each set of the four columns 48 to 52, inclusive, and 53 to 56, inclusive, of the carriage B is an elevator C, each elevator C including upper and lower rectangular fabricated steel frames generally designated by the

reference numerals

76 and 77, respectively. The upper frame 76 includes front and

rear channels

78 and 79 welded to and between an outer and inner side channels 81 and 82 (see Fig. 3). Welded to and between the two side channels S1 and 32 midway between the

channels

78 and 79 is a channel 83.

Extending between the front channel 78 and the central channel 83 and welded thereto is a longitudinally extending channel 84 located to the left of the longitudinally central line of the frame 76 as viewed in Fig. 2. Similarly extending between the central channel 83 and the rear channel 79 and welded thereto is a longitudinally extending channel 35 located to the right of the central line of the frame 76 as viewed in this figure. Aixed to the upper face of the channel 83 of each elevator C midway between its ends, is a fabricated steel eye 86 arranged to be engaged by the hook 68 thereby to hold its elevator C in its uppermost inoperative position. As best shown in Fig. 5, the upper face 87 of the I 86 is contoured in conformity with the lower edge of the hook 68 and serves as a stop to limit the upward movement of the elevator C during the operation of the tamping machine.

The lower elevator frame 77 includes a pair of front and rear channels 88 and 89 welded to the ends of

side channels

91 and 92. Extending between and welded to the four corners of the upper and lower elevator frames 76 and 77 are tubular columns 93 slidably disposed over the two sets of columns 48 to 52 and 53 to 56. Welded to the eight corners of each of the elevators so formed are stilfening webs 94 and fastened to the front and rear side beams 91 and 92 of the lower elevator frame 77 on either side of the transverse center line thereof are channels 9S and 96. Welded to the side beam 91 and to the ends of the transverse beams 95 and 96 is an upwardly extending channel shaped bracket 97 and similarly welded to the opposed channel 92 and to the opposite ends of the transverse channels 95 and 96 is a bracket 98 (see Figs. l, 3, 4 and 6).

Extending fore and aft of the lower frame 77 of each of the elevators C are brackets 101, 102 (see Fig. 3), 103 and 104 (see Figs. l, 4 and 6) and extending between and fastened to the brackets 101, 97 and 102 is a track 10S having arcuate ends. Similarly secured to the

brackets

103, 98 and 104 is a track 106. Fastened to both of the lateral faces of each of the

tracks

105 and 106 are guide plates 107. Also fastened to the tracks 106 are cam tracks 106a each provided intermediate its ends with an inclined cam surface 108 (see Figs. 3, 4 and 6), the function of which will be presently described in conjunction with the description of the tamper crossheads.

Tamper crossheads Mounted on and between the tracks 105 of each of the elevators C on either side of the transverse center lines thereof a pair of longitudinally opposed tamper crossheads D. As best shown in Fig. 7, each crosshead D includes a pair of laterally opposed plates 111and112 interconnected by transversely extending upper and

lower channels

113 and 114 Welded thereto.

Fastened to the upper ends of each set of opposed plates 1 11Y and 112 is a downwardly flanged channel 115V and secured between these flanges and the plates 111 and 112 is a U-shaped plate 116, held in spaced relation from the plates 111 and 112 by a spacer 117. Slidably disposed WithinV the confines of each plate 116 is a bearing 11S, these bearings. being vertically adjustable by screws 119 threaded inthe spacers 117. Supported. by each pair of bearings 11%v is a shaft 121 and journaled on the ends thereof are rollers 122 arranged to travel on the tracks 105211111 106. In connection with the vertical adjustment of the bearings 118, it is to be noted that the plates 111 and. .1.1.2 are, formed with slots 123 to permit the vertical movement of the. shaft 121.

Extending through and supported by the plates 111 and 112 below the level of the

tracks

105 and 106 on either side of the transverse axis of each elevator are a pair of longitudinally spaced shafts 125 and journaled on the ends thereof are rollers 126 arranged to engage and travel over the lower face of the

tracks

105 and 196. It should here to observed that each set of three rollers- 122 and 126 constitute a three point support for its associated tamper crosshead B and that this structure constrains the crossheadA tomove in an arc and` determines' the angularity of the longitudinal center line of each. tamper crosshead withk respect: tothe vertical.

Fastened. to,l and between the channels 1'13 and 115 are a pair. f lateraldy opposedl platesv 127 and. 128 each provided with: an opening 129. for the reception of the shaft 121 (Fig. 7 Mounted in the. upper ends of` the plates 12.7 and 1.2.8 is a pin 1.31, the function of which will be later described in conjunction with a description of the control. circuit for spreading and retracting the; tamper crossheads.. Welded to.. and between the. channels 113 and. 1,14. are. a set of coll-ars 1132,` 13,3 and 134". and'v fitted within each. of these. collars is a bearing sleeve 135.

Tamper assemblies Associated with each of the tamper crossheads. D isa tamper assembly E comprising` an H beam 136; Bolted toeach H beam, 136' is a set of three upwardly extending tubes 1?;'7 each arranged to slide within one of thebearing sleeves 135; Surrounding the upper end. of each of the tubes 1371s a spring 138 seated' at its lower end on the top of=itsV associated beam 113 and' engaging at its upper end a washer 139` secured to its tube 137 by a nut 141.. Similarly` mounted on the lower end of each tube 13.7 is a spring 142 abutting the channel 114 at its upper end and seated on its, lower end on the ange or foot 143 of its r associated tube 1317i As a result of this. construction, the tamper assemblies are always biased by the. springs. 138 and1 142 to their neutral or central position on the tamper crossheads D..

Secured tothe lower face of the H beam 136 in axial alignment, with tubes 137 i's a set of three pneumatically operated tamper guns 144 of standard construction 'and includinga spade shaped tamping. head 145.

As best shown in Fig. 9, a gasket 146 is interposed be.- tweenv the ange 147 of the tamper guns 144 and the H beam 136V to which the guns 144. are bolted. Formed on one o f; the side walls of the beam 136 are internally threaded bosses 148 andprovided in each boss and in the beam 1316' is a passageway 149Ycon1municating through a hole llforrned in the gasket 146, with the interior of one ofthe guns 144.

As shownin Eig. 7, one tamper headv 145 is positioned on, the inside of' each of rails. 2,2 and 23, whereas two tamperhead's are positioned onV the outer sidesthereof.

Control circuit for laterally moving the carriage B ami for raising and lowering the elevators C Associated with the truck A, its carriage B and the two elevators C, is an interlocked control circuit F schematically illustrated in the top portion of the Fig. 161,- the details of portions thereof being also illustrated iny Figs.- 1l to 19, inclusive.

To obtain right and left-hand movement of the carriage B relative to the truck A and to center the carriage B' over the truck A, there is mounted on the central transverse channel beam 9 of the truck a cross-arm 1521 and pivoted to the ends thereof are cylinders 153and-154, each containing a piston connected respectively to`

piston rods

155 and 156. As illustrated in Figs. 17 and 19, inclusive, the free ends of the connecting rods 155 and 156- are pivoted to the ends of a rocker-arm or first-class lever 157 which in turn is pivoted to the central channel beam 45 of' thecarriage B. Associated with the cylinders 1'53 and 154 is a duplex rotary disc four-way valve 158' available on the market as a 3/4 Hannin Duplex Air Valve- Model B75 and which has a left-hand position, a center position and a right-hand position. Communication between the upper ends of the

cylinders

153, 154, respectively, and the valve 158is established by

airlines

159 and 161. Similarly communication between the 'lower ends of the

cylinders

153 and 154 and the valve 158 is respectivelyl established by lines 162 and 163 (see Figs. 16 to 19').

The valve 158 is provided with a discharge port 164 communicating with the atmosphere and with al port 166'` communicating with any suitable source of compressed air such as 'for example the manifold tank 166n mounted on the lower rectangular frame of the carriage B as shown in Fig. l. The tank 166a merely serves as a` manifold and communicates through the line 167, an in-line oiler 168-,-- a line 169 and the valve 171 with a high pressure tank` 172. As shown in Figs. l and 2, the tank 172 ismountedon. a forward extension 173 of the lower frame of the carriage B. Although not illustrated, the tank 172 is' arranged to receive air from a source of compressed air.

As indicated in Fig. l2, the rotary disc of the valve 15sv is actuated by a stub shaft 174 terminating in a hollow sleeve 175, this sleeve being provided with internaL-diametrically opposed key-ways 176 of rectangular crosssection. Formed integral with the body of thevalve` 158 is a bearing collar 177 for the accommodation of the' sleeve 175. Welded coaxially to the end ofthe collar 117-7" is a collar extension 178 formed with a counter-bore17-9 for the accommodation of the outer end of the sleeve- 175,- and formed with a bore. 181 provided with diametrically' opposed key-ways 182 in a longitudinal alignment with the diametrically opposed key-ways 176.

Slidable in the two sets of key-ways 176 andt182is av key 183 pivoted to the end of a control shaft 184. As a result of this construction, it is to be noted that'whenA the key 183 is Within the key-Ways 176, the rotation ofthe shaft 184 results in the rotation of the valve shaft 174i and therefore in the rotation of the control disc of thev valve. When the valve 158 is in its center position thel key-ways 176 are in alignment with the key-ways 182 and consequently key 185 can be drawn thereinto. Whenthel key is in its latter position rotation of the shaft 184'and' therefore operation of the valve 158 is precluded, for thev sleeve 178 is welded to a. fixed portion of the valve 158'. It will therefore be seen that when the key 183 is' withdrawn from key-ways 176, the valve 158- is left inits` center' position.

The shaft 184 and valve 153 are mounted ina bearingV 185. carried by a bracket 186 supported by the carriage B. lournaled' on the shaft 184 are sleeves 187and 188; longitudinal movement of these sleeves on the shaft 184 be# ing precluded by collars 189 fastened thereto. Extending' outwardly from each of the

sleeves

187 and 188, respec` tively, and formed integral therewith arefingers 19'11and 1-92, each providedA with an elongatedslot-193.`

Also mounted on the carriage bracket 186 is a two position (left-hand and' right-hand) four-way rotary disc valve 194 of standard construction and available on the market as a Hannin 1%" Four-way, Air-controlled Valve- Model T50. The disc of this valve is formed integral with an outwardly extending operating stub shaft 195 and clamped to the end thereof is an arm 196 provided at its end with a pin 197 arranged to ride in the slot 193 of the inger 191. Compressed air is delivered to the valve 194 through a manifold 198 and a liexible line 199 communicating with the tank 166e. Provided in the valve 194 are

ports

201 and 202, the port 201 being connected through a exible line 203 with the lower end of an elevator cylinder 204 mounted on the left-hand side of the lower frame of the carriage C as viewed in Fig. 2 and as seen in side elevation in Fig. l. As indicated in Fig. 3, the cylinder 204 includes an upwardly extending piston rod 205 provided at its upper end with a fabricated litting 206 pivoted to the beam 83 of the left-hand elevator as viewed in Fig. 2.

Connected to the air discharge port 202 of the valve 194 is a flexible pilot air-line 207 for actuating a pilot valve for controlling the operation of the tamper guns as will be presently described. Also communicating with the manifold 198 is a four-way disc valve 208 identical to the valve 194 and provided with a exible airline 209 communicating with a four-way pilot valve 211 serving to establish communication between an airline 212 connected with the lower end of an elevator cylinder 213 and with an airline 211a communicating with a suitable source of air pressure. The valve 211 is of standard construction and is available on the market under the trade name Modernair Model 0502. The cylinder 213 is in all respects identical to the cylinder 204, is mounted on the carriage B within the confines of the right-hand elevator C as viewed in Fig. 2 and' includes a piston connected with an upstanding piston rod 214. As best shown in Fig. 2, the upper end of the piston rod 214 terminates in a bifurcated litting 215 pivoted to the central channel beam of the upper frame of the right-hand elevator C.

Connected to a port 216 of the valve 208 is a tiexible pilot airline 217 corresponding to the airline 207 connected to the valve 194, and which communicates with a pilot valve 218 similar to the valve 211. As shown in Fig. 16, the pilot valve 218 communicates with the pressure tank 172 through a flexible airline 219. Air from the line 219 passes through the valve 218 under the control of air entering the pilot valve from the line 217, and

passes through a line 221 into the upper end of the tamper guns 144. Although not shown in Fig. 16, each of the three tamper guns on each side of each of the elevators is actuated in the manner above described.

As shown in Fig. 12, the disc of the valve 208 is formed integral with an outwardly extending stub shaft 223 and clamped to this shaft is an arm 224 provided at its end with an upstanding pin 225. The pin 225 extends through the slot 193 formed in the finger 192 and as a result of this construction the axial movement of the shaft 184 serves simultaneously to control both of the valves 194 and 208. Secured to Athe free end of the shaft 184 is la notched' operating wheel 227 which as shown in Figs. l and 2 extends rearwardly of the machine and is conveniently located to an operators seat 228 mounted on a rearward extension 229 of the carriage B. When the notch of the wheel 227 is in its lowermost position, the valve 158 is in its center position and the carriage B is centered over the truck A.

The valve ports of the valves 194 and 208 are so arranged that upon the rearward movement of the control shaft 184 communication between the pressure tank 166a and the lower sides of the two

elevator cylinders

204 and 213 is established thereby to raise both of the elevators C. Upon the forward movement of the control shaft 184, air to the lower side of the

elevator cylinders

204 and 213 is cutoff, whereupon lowering of the two elevators takes place, -air from the lower end of the

elevator cylinders

204 and 213 being allowed to quickly escape through the discharge ports of the pilot valves 211. Also upon the forward movement of the control shaft 184 to a point where the key 183 is disposed within the key-way 176 of the sleeve 175, rotation of the control wheel 227 serves to actuate the valve 158 for imparting transverse movement to the carriage B. Rotation of the wheel 227 to the right causes the carriage to move to the right whereas the rotation of the wheel to the left causes the carriage to move to the left. From an inspection of Figure 16, it will be seen that transverse movement of the carriage can be eiected only when the elevators C are in their down or operative position. It should also be noted that compressed air can reach the guns 144 only when the valves 194 and 208 are in their right-hand positions as viewed in Fig. l2 or, in other words, when the elevators C are in their lower positions or are approaching their lower positions.

Control circuit far spreading and retracting the tamper crossheads to determine the cant or inclination of the tamper assemblies and for axially reciprocating the tamper assemblies Welded to the upper frame of each of the elevators C are a pair of depending, transversely spaced and longitudinally offset

brackets

231 and 232 and pivoted respectively to these brackets are the upper ends of

air cylinders

233 and 234, each including a piston rod 235. As best shown in Figs. 3 and 7, each of the piston rods 235 terminates in a bearing fitting 236 pivoted to the pin 131 of its associated tamper crosshead D. It is therefore apparent that actuation of the

cylinders

233 and 234 serves to move the tamper crossheads along their respective arcuate tracks land 106, thereby to change the inclination of each crosshead assembly.

As schematically illustrated in Fig. 16, the inner end of each of the

cylinders

233 and 234 communicates through a liexible airline 237 with a four-way foot pedal type valve 238. Communication between this valve and the outer end of each of these cylinders is established by flexible lines 239. The valve 238 has two

airlines

241 and 242 connected therewith, each communicating with the manifold or tank 166e. It should here be noted that as shown in Fig. 2 there are two valves 238, one for each side of the machine and that as shown in Fig. 1, they are located conveniently to an operator seated in the seat 22S. Since these valves are of standard construction and commercially available on the market as Hanniin" Model F Air Rotary Valves, there is no particular reason for setting forth the details of their construction and operation. Valves of this class are provided with foot pedals 243 which when successively depressed serve successively to reverse the direction of flow of air through the

lines

237 and 239. After each depression of the pedals 243, they are spring returned to their starting position.

Mounted on the channel 114 of each of the crosshead assemblies D between the inner and central tamper assemblies E is an air cylinder 245 including a piston rod 246 (see Fig. 7). The lower end of each of the piston rods 246 is fastened to a rubber cushioning block 247 mounted in a cup 248 which in turn is secured to the beam 136. From this construction it will be seen that the reciprocation of the piston rod 246 causes the reciprocation of its associated bank of tamper assemblies E against the biasing action of the

springs

138 and 142. Connected respectively with the upper and lower ends of each of the cylinders 245 are

flexible airlines

249 and 251 communicating with a four-way pilot valve 252 (similar to the valve 211). As indicated in Fig. 16, the valve 252 communicates through a flexible airline 253 with the manifold tank 166a and is provided at either mosphere. Also connected with the pilot valve 252 isa flexible airline 2.56- communicating with an automatic air actuated four-way timer valve 257 available on the.

market as a Mead-Maticl Timer-Model No. 1. Included in the valve 257 is an adjustment screw 258 for adjusting the cycle of operation thereof. Connected to the valve 257 is a flexible airline 259` communicating with a. three-way cam valve 261, this Valve being mounted on a bracket 262 afxed to one of the plates 112. Included in the valve 261 is a piston rod 263 actuated in a wellknown manner by a piston disposed within the valve body of the valve 261. Formed integral with the valve 261 is a bracket 264 and pivoted to this bracket is arocker-arm 265, the inner end of which is pivoted to the outer end of the piston rod 263. Mounted on the free end of the rocker-arm 265 is a cam follower roller 2661 arranged to ride on the cam surface S (see Figs. 4 and 16). Connected to the valve 261 is a exible airline 267 communicating with the manifold tank 166e. The valve 261 is of` standard construction and procurable on the-market.

from the Valvair Corporation as a 3way cam. valve Model 153340.

From an inspection of Figs. l, 3 and 4, it will be noted that when the tamper crosshead assemblies D are in their innermost position, each cam follower roller 266 is out of engagement with the cam tracks 1068', thevalve 261y being closed at this point in thecycle of operation.. However, when the crosshead assembly D moves outwardly under the inuence of the opposed pairs ofcylinders 233 and 234, the cam follower rollers 266 move outwardly and in so doing engage the inclinedv cam track surfaces 108 thereby to open the valves 261 and to permit air from the lines 277 to pass throughy the lines 259 into the air timer valves 257.' The delivery of` compressed air to the timer valves 257 activates them and this causes them to periodically deliver airV to the pilot` Valves 252... Upon activation off the pilotvalves 252 in response to the action of the timer valves 257, the tamper cylinders 245 raise and lower the tamper assemblies E atal rate corresponding to the cyclefor, which the timervalves 2.57 have been set.

MISCELLANEOUS.

As illustrated'in Fig. 6, the lowerterminal movement ofl each of the elevators C is arrestedf'by a; wooden block 281 removably seated'in a` retainer282mounted-on eachl ofthe lower side rails ofthe carriage; B. Ifit is desired to change the lower terminal position of: the elevators, it is only'necessaryto substitute a block of VdiierentA length for theblock Zl.

As Ipreviously explained, the elevators C are suspended' from the hooks 68"y when the tamping-` machine is in its inoperative or travel position. However, since-in this position the lower endsof the tamper heads 145' may engagefrogs associated with the

rails

22 and 23 asthetamping machine travels thereover, it is preferable to elevate the tamper assembliesE relative totheir` associated; crossheads D'whenever the machine is in motion; IForthis-purposev andas illustrated'in-Figs. 3 and' 4, an outwardly extending bracket 234 is loosely suspended from each ofthe channels95 and' 96 of eachof; the elevator assemblies-by a bolt 285 and by a bolt 286'. Disposed between` each oii the-channels 95 and 96 andI its associated bo1ts-286fis a spring 287 held in place atits upper endby'va nutf 288i threaded on tothe upper endl of "the bolt. a result of thisconstruction, the bracket 284 is bi'ased upwardly so.

as normally to seat against the-upper web of its associated channel.

formed therein. tamper assemblies E, can automaticallybe raised inresponse tothe inward movement of thetampercrosshead's.

against the biasing'action of the springs 142; When the tamper heard assemblies Dv are moved outwardly relative to each other under theinuenceofthe cylinders 233 and'.

234, the ngers 291 are., disengaged from their seats 289 whereuponthetamper assemblies E assume their normal positions as illustrated for example in Fig. 6.

Operation of machine ln the inoperative or travel position of the ramping machine as above described, and as shown in-Figs. 1 and 2, the carriage Bris centered over the truck A; both elevators C are suspended in their uppermost position fromtheir respective hooks 68; the tamper crossheads D are.

in their inner or closed positions, each tamper crosshead making an angle of about 15 with the vertical; andthe tamper assemblies E of eachk tamper crossheadY are heldI in their uppermost positions by the engagement ofthefmgers 291l with the arms 284. I-n this position of the machine the control circuits F and G are in the positions schematically indicated in the upper and lower portions respectively of theFig. 16, the control shaft 134 and the valves 194 and 208 being in their right-hand positions asy are supported thereby, the hooks 63 can be released fromk their associated eyes 86 by pulling on the cables 72. If now the control wheel 227 is pushed inwardly (to the left as shown in Fig. 16), the, pilot valve 2li will be activated thereby to permit the ldischarge through these Valves of air from the lower end-s of the

elevator cylinder

204 and 213 with the result that the elevators C fall of their owny weight to their lowermost position as determined by the stops 281. Upon the initial downward movement of the elevators, the cables 72 are released to permit the return of the hooks 68 to their vertical positions under the influence of the springs 69 whereupon the lower ends of these hooks then serve as stops to limit the upper travel ofv the elevators C. Concurrently with the release of air fromV the lower ends of the elevator cylinders the pilot valves, 218 are actuated under the control of the Valves 194 and,`

208y to establish communication between the

airlines

219 and 221, thereby to vibrate the guns 144. Although the elevators are now. in their lower operative position: and the guns are vibrating, the tamper crossheads D are still in their closed positions with the tamper assemblies E, each making an angleA of about 15 toy the` vertical and each supported on its associatedbracket 264, all as iliustrated in Fig.r 4., Also as herel shown, the tamper heads are symmetrically positioned somewhat above one of the tics25, two pairs of tamper heads being disposedy on the outside ofjeach of the rails22, and 23l and one pair of tamper heads being disposed on the inside of each rail as indicated in Fig. 2.

The tamperl crosshead D and their associated tamper assemblies Eof; either or both, ofthe elevatorsA C can now be spread from their closed position as shown in :full line inFig. 6 to theirV open position as shown in dot-dash line in this iigure, this being accomplished by selectively depressing` either or both of the foot pedals 243 of the valves 238. InA this position ofthe crossheads they each make an angle of about; 30 with the vertical (60 between opposedy crossheads). Due to the construction of the valves,238, it is not necessaryV to' maintain the

foot pedals

2,43` depressed to hold the crossheads inthis position, the pedalszmerely returning to their neutral position eachv timethat they` haveV been depressed withoutchanging the position of their valves. Asubscquent depression of the pedals 243 reverses the direction of the iiow of air into the cylinders 233 thereby to bring the crossheads D back to their innermost position. In the outermost position of the crossheads D and their associated tamper assemblies E the tamper gun heads 145 are directed to a point beneath the tie being operated on, this being indicated in dot-dash line in Fig. 6. Here it should bc observed that the crossheads D and their associated tamper assemblies E, when moving from their closed positions to their open positions, rotate about the ilower ends of the tamper heads 145.

During the outward movement of the crosshead assemblies D, their associated cam 4follower rollers 266 engage the inclined cam surfaces 108 and in so doing, open their associated Valves 261. Upon the opening of these valves, air from the lines 277 passes through the valves 261; through the airlines 259; and into the timer valves 257 which are now activated to periodically open and close on a cycle predetermined by the setting of the adjusting screw 258. The timer valves 257 therefore serve to produce periodic impulses of air in the iine 256 thereby to activate the pilot valves 252. The pilot valves 252 in turn open and close on the same cycle of operation for which the valve 257 has been set thereby to raise and lower their associated tamper assemblies E, which in turn causes the tamper heads 145 to move up and down within that portion of the ballast 26 beneath the tie 25. The tamper heads 14,5 are now in full operation but without lateral movement, the carriage B being centered over the truck A.

Since to lower the elevators C it is rst necessary to move the control shaft 184 to the left or inwardly as viewed in Fig. 16 to release air from the lower part of the

elevator cylinders

204 and 213 to the valves 211, it will be seen (Fig. 12) that the key 183 is now in engagement with the key-way 176 of the hollow sleeve 175 and that now it is possible to operate the valve 158 by turning the wheel 227 thereby to move the carriage B either to the lett or to the right, respectively, depending upon whether the wheel 227 is turned to the right or to the left. Since the tamper head assemblies E insofar as transverse movement is concerned move bodily with the carriage B, the tamper gun heads 145 can be given a corresponding lateral displacement either to the right or to the left as indicated in dot-dash line at the lower end of Fig. 7. In this connection, it should be observed that due to the construction and operation of the mechanism for effecting this lateral movement as indicated in Figs. 17, 18 and 19, a rotation of the control wheel 227 to the left causes the carriage to move to its extreme left-hanl position and likewise a rotation of the control wheel to the right causes the carriage to move to its extreme right-hand position, no intermediate position of the carriage being possible.

At this point in the cycle of operation of the machine the controi wheel 227 is in its forward position but with its notch still directed downwardly as indicated in Fig. 17. This means that the valve 158 is in its central position corresponding to the dead center position of the carriage B over the truck A and that the key 183 is disposed in the key-ways 176. In this position of the valve 158 the carriage translating cylinders are in the condition illustrated in Fig. 17, air under pressure being applied to the upper end of the cylinder 153 and to the lower end of the cylinder 154.

To move the carriage B to the right, the control wheel is rotated in that direction whereupon the valve 158 operates to deliver air to the lower side of the cylinder 153, to permit air from the upper end of this cylinder to escape through the valve 158, and to continue to deliver air to the lower end of the cylinder 154. Since the piston rod 156 is thereby locked against outward movement, the resulting inward movement of the piston rod 155 causes the rocker-arm 157 to move with it and to pull the carriage with it to the right and to place the system in the condition Ishown in Fig. 18.

If now the control wheel 227 be rotated counterclockwise, the valve 158 will be brought to or pass through its central position and in so doing the system will return to or pass through the condition illustrated in Fig. 17 with the carriage B again centered over the truck A.

Upon the continued rotation of the control wheel to the left, the valve 158 then operates to deliver air to the upper ends of both of the

cylinders

153 and 154 and to permit the escape of air from their lower ends through the discharge port of the valve 158. The concurrent outward movement of the

piston rods

155 and 156 pushes the carriage B to the left, the system now being in the condition illustrated in Fig. 19. If now the control wheel 227 is rotated to the right, the system will again be brought to or pass through its central position as indicated in Fig. 17.

It will therefore be seen that by rotating the control wheel 227 in either direction, the tamping heads can be translated back and forth between the rails and beneath the tie being straddled. Here it should be noted (Fig. 7) that due to the broadened ends of the tamper heads, they actually underlie the base of the

rails

22 and 23 during their limiting lateral travel and that if the elevators were to be raised during this time, the resulting upward movement of the tamper heads would be obstructed by rail bases. However, as already indicated, this contingency is impossible for the elevators C can be raised only when the carriage B is in its head center position, in other words, only when the key-ways 182 are in longitudinal alignment with the key-ways 176 so as to permit the control wheel 227 to be pulled rearwardly.

The crossheads D can be moved from their spread positions to their closed posiitons at any time by simply depressing the foot pedal of the valves 238 but as the crossheads move inwardly their associated valves 261 are actuated to deactivate the timer valves 257 and the pilot valves 252, thereby to cut off the air supply to the cylinders 245 and to stop the up and down movement of the tamper assemblies E. Also upon the inward movement of the crossheads D to their closed positions, the fingers 291 of the tamper ride over the outer inwardly inclined ends of the brackets 284 to seat in the recesses 289 of the brackets. In so doing, the elevator assemblies are raised against the biasing action of the springs 142 to a sufficient extent to permit the tamper heads 145 to clear any frogs or the like associated with the

rails

22 and 23. When moving the tamping machine even from one tie to the next tie it is advisable to bring the machine to its starting or traveling position previously described.

The two elevators C and their associated tamping mechanism can be operated independently of each other, this of course being essential in taking care of discrepancies in the condition of the ballast under the two

rails

22 and 23. As a result of the construction and operation of the machine and more particularly the transverse spacing and movement of the tamping heads, the central zone of the ballast midwayA between the two rails is never tamped, this being expressly avoided so as to prevent the formation of a transversely crowned ballast. A crowned ballast is objectionable for the reason that it would support the ties at points intermediate the rails and therefore the ties would be free to rock about their centers.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. A tampingmachine comprising: a guided truck; a guided carriage mounted on said truck for transverse movement thereon; a guided elevator mounted on said carriage for vertical movement relative thereto; a guided tamping gun carrier supported by said elevator for downward arcuate movement relative thereto in a longitudinal vertical plane and for independent vertical movement relative to said elevator; and a tamping gun mounted on said tamping gun carrier.

2. A tamping machine comprising: a guided truck; a

guided vvcarriage mounted on :said truck Vfor transverse movement thereon; Ja guided elevator mounted .on said carriage for'vertical movement relative thereto; a guided tamping gun carrier mounted on said elevator for downward arcuate movement relative 'thereto in. a longitudinal vertical plane and "for vertical movement relative to said elevator; and a tamping gun mounted on said carrier in parallelism with said longitudinal vertical plane.

3. A tamping machine comprising: a guided truck; a 'guided carriage 'mounted on said truck for transverse movement thereon; a guided elevator mounted on said carriage Vfor vertical .movement relative thereto; a track inclined fore and aft of said machine supported by said elevator; a tamping Vgun carrier supported from said track; means .for constraining saidcarrier to maintain a constant angle with said track while lmoving thereon; and a tamping `gun xed to `said carrier in a longitudinal vertical plane.

4. A tamping machine comprising: a guided truck; a guided carriage mountedon said truck `for transverse movement thereon; amotor for lactuating said carriage; a `guided elevator'mounted on said carriage -for vertical movement relative thereto; .a duid cylinder .including a piston and .a piston rodrfor actuating said elevator, said cylinder being mounted on saidcarriage and having its pistorrrod vconnected with saidelevator; a guided tamping gun carrier supported by said elevator for downward arcuate movement relative thereto in a longitudinal vertical plane and for independent vertical movement relative to said:elevator; atuid cylinder disposed between said carrier and said elevator and secured to said carrier and elevator for imparting said arcuate movement to said carrier; a fluid cylinder-disposedibetweensaid elevator and said carrier Vfor imparting-said independent vertical movet ment tosaid `carrieryand-a tamping `gun mounted-on said carrier.

5. A tampingmachine comprising: a truck arranged to travel on the `rails of a railroadtbed, said bed including ties for supporting said rails and ballast for supporting said ties; a carriage mounted on said truck for transverse movement thereon; an elevator mounted on said carriage; a pair of longitudinally spaced tracks mounted on said elevator, said tracks being inclined towards each other fore `and aft of said machine; a tamper crosshead mounted on each of said tracks for longitudinal movement towards and away from each other; means associated with each of said crossheads and with its supporting track for constraining said tamper crosshead to maintain a subst-antially constant angle relative to its said supporting track; a tamping gun carrier mounted on each of said crossheads for linear movement relative thereto; and a tamping gun mounted on each of said carriers in a longitudinal vertical plane.

6. A tamping machine comprising: a truck; a carriage mounted on said truck for transverse movement thereon; an elevator mounted on said carriage for vertical movement thereon; a pair of longitudinally spaced tracks mounted on said elevator, said tracks being inclined towards each other; opposed tamper crossheads mounted on said tracks for longitudinal movement towards and away from each other fore and aft of said machine; means associated with each of said crossheads and with its supporting track for constraining said tamper crosshead to maintain a substantially constant angle relative to its supporting track; a tamping gun carrier slidably mounted in each of said crossheads for linear movement relative thereto; spring means for resiliently biasing said tamping gun carriers against said linear movement in either direction; and a tamping gun mounted on each of said carriers in a longitudinal vertical plane.

7. A tamping machine comprising: a guided truck; a carriage mounted on said truck for transverse movement thereon; a pair of laterally spaced elevators mounted on said carriage; a pair of longitudinally spaced tracks mounted lon each 'of `said elevators for vertical movement therewith,v saidtracks being inclined towards each other fore and aft of said machine; `a pair oflongitudinally opposed `tamper crossheads mounted on'each pair of longitudinally opposed tracks for movement towards and Vaway from each other; means associated with each of said crossheads and 'with its supporting track for `constraining said tamper crosshead to maintain a substantially constant angle relative'to its supporting track; `a tamping gunl carrier slidablymounted in each of said crossheads for linear 'movement relative thereto; and a tamping gun mounted on each of said carriers in a longitudinal vertical plane.

8. A -tamping machine comprising: a guided truck; a carriage mounted on said `truck for transverse movement thereon; an elevator mounted on said carriage; a pair of longitudinally spaced andtaligned tracks mounted on said elevator, 'said tracks being inclined towards each other fore'and aft of said machine; opposed 'tamper crossheads mounted on said tracks for longitudinal 'movement towards and away from each other, each of said crossheads inclu-ding a central upper roller supported on one of said .tracks and a pair of longitudinally spaced lower rollers engagingthe lower side of said track thereby to constrain said crosshead to maintain a substantially constant angle with its supporting track; a tamping gun carrier slidably mounted in each of said crossheads for -linear movement relative thereto; and a tamping gun mounted on each of said carriers in a longitudinal vertical plane.

9. A tamping machine comprising: a guided truck; a carriage mounted on said truck for transverse movement thereon; a cross-arm xed to said truck; a rockerarm pivoted to said carriage; a duid cylinder including a piston and `a piston rod pivoted to each end of said cross-arm, the outer ends of the `piston rods of .said cylinders being connected respectively to the ends of said rocker-arm; a pair of four-way control valves associated with said machine; exible "fluid lines connecting said valves with the opposite ends of each of said cylinders, said valves having Huid intakes and discharge ports; an elevator mounted on said carriage; a pair of longitudinally spaced tracks mounted on said elevator, said tracks being inclined towards each other; a tamper crosshead mounted on each of said tracks for longitudinal movement towards and away from each other; means associated with each of said crossheads and with its supporting track, for constraining said tamper crosshead to maintain a substantially constant angle relative to its supporting track; and a tamping gun slidably mounted on each of said crossheads for linear movement relative thereto.

l0. A tamping machine comprising: a guided truck; a guided carriage mounted on said truck for transverse movement thereon from a central position to a limiting lateral position on either side of said central position; first iiuid responsive means for actuating said carriage; a first valve for controlling said rst fluid responsive means; a guided elevator mounted on said carriage for vertical movement relative thereto; an elevator actuating cylinder for actuating said elevator; a second valve for controlling said elevator actuating cylinder; interlocking means between said first and second valves for maintaining said rst valve inactive until said second valve is in a position corresponding to the lowermost position of said elevator; a guided tamping gun carrier supported by said elevator for downward arcuate movement relative thereto in a longitudinal vertical plane and for independent vertical movement relative to said elevator; and a tamping gun mounted on said tamping gun carrier.

1l. A tamping machine comprising: a guided truck; a guided tamping gun carrier mounted on said truck for downward arcuate movement and for independent longitudinal vertical movement relative thereto; a fluid cylinder for raising and lowering said carrier; a tamping gun 15 mounted on said carrier; a pilot valve communicating with the upper and lower ends of said cylinder; a timer valve for controlling said pilot valve; a second uid cylinder for imparting arcuate movement to said carrier; and means responsive to the arcuate movement of said carrier for activating and inactivating said timer valve.

12. A tamping machine comprising: a guided truck; a guided carriage mounted on said truck for transverse movement thereon; a guided elevator mounted on said carriage for vertical movement relative thereto; a guided tamping gun carrier supported by said elevator for downward arcuate movement and for independent longitudinal vertical movement relative thereto; a fluid cylinder mounted on said elevator for raising and lowering said carrier; a tamping gun mounted on said carrier for movement in parallelism with the vertical movement of said carrier; a pilot valve communicating with the upper and lower ends of said cylinder; a timer valve for controlling said pilot valve; a second uid cylinder for imparting arcuate movement to said carrier; and means responsive to the arcuate movement of said carrier for activating and inactivating said timer valve.

13. A tamping machine comprising: a guided truck; a guided carriage mounted on said truck for transverse movement thereon; a guided elevator mounted on said carriage for vertical movement relative thereto; a guided tamping gun carrier supported by said elevator for downward arcuate movement and for independent vertical movement relative thereto; a tamping gun mounted on said carrier for movement in a longitudinal vertical plane; uid actuated power means connected between said truck and said carriage for imparting transverse movement to said carriage in either direction relative to said truck; a rst valve for controlling said fluid actuated power means; an elevator actuating cylinder connected between said carriage and said elevator; a second valve for controlling said elevator actuating cylinder; interlocking means between said first and second valves for maintaining said first valve inactive until said second valve is in a position correponding to the lowermost position of said elevator; a carrier actuating fluid cylinder mounted on said elevator for raising and lowering said tamping gun carrier; a pilot valve communicating with the upper and lower ends of said carrier actuating cylinder; a timer valve for controlling said pilot valve; a cylinder for imparting arcuate movement to said carrier; and means responsive to the arcuate movement of said carrier for alternately activating and inactivating said timer valve.

14. A tamping machine comprising: a guided truck; a guided carriage mounted on said truck for transverse movement thereon; a guided elevator mounted on said carriage for vertical movement relative thereto; an arcuate carrier track supported by said elevator; a tamping gun carrier supported from said track; means for constraining said carrier to maintain a constant yangle with said arcuate track while moving thereon; a cam track supported by said carrier track; a cam follower supported by said carrier and arranged to travel over said cam track; a tamping gun iixed to said carrier; a uid cylinder mounted on said elevator for raising and lowering said carrier; a pilot valve communicating with the upper and lower ends of said cylinder; a timer valve for controlling said pilot valve; a second luid cylinder mounted on said elevator for moving said carrier over said arcuate track; and a timer valve control valve mounted on said cam follower, said timer valve being under the control of said control valve, and said control valve being under the control of said cam follower and its associated cam track.

References Cited in the le of this patent UNITED STATES PATENTS Re. 23,687 Hursh et al. July 21, 1953 1,351,106 Hastings Aug. 31, 1920 1,351,246 Hastings Aug. 31, 1920 1,819,945 Collet Aug. 18, 1931 2,587,324 Hursh et al. Feb. 26, 1952 2,734,463 Hursh et al. Feb. 14, 1956