US2315993A - Percussion tool - Google Patents

Description

April 6, 1943.

C. S. WEYANDT EITAL PERCUSSION rooL Filed Oct. 3, 1941 2 Sheets-Sheet 1 ATTORNEY:

April 6, 1943.

c. s. WEYANDT ETAL PERCUSS ION TOOL Filed Oct. 3, 1941 2 Sheets-Sheet 2 INVENTORS. (0/ /57 Me v0 0a? Patented Apr. 6, 1943 PERCUSSION TOOL Carl S. Weyandt and Edward J. Mission, Homer City, Pa., assignors to Syntron Company, Homor City, Pa., a corporation of Delaware Application October 3, 1941, Serial No. 413,533

a In Belgium June 4, 1938 11 Claims. (Cl. 112-126) grease or oil, and which has great durability un-,

der rapidly repeated impact.

Another object is the provision of a percussion tool having a free reciprocating piston operated by a pulsating field in synchronism therewith,

which may be used in non-horizontal position,

-and which may be lifted from the work without destroying the synchronism of the piston.

A further object is the provision of a percussion tool having few wearing parts which' may be readily replaced when they become worn.

A further object is the provision of a tie tamper for rock ballast intended to carry heavy loads,

which has high power, and which is operated from a source of alternating current without make and break devices.

A further object is the provision of a tie tamping apparatus for operating one or more tie tampers, and which may be remotely controlled to start or stop simultaneously.

The accompanying drawing shows a preferred modification of the invention by way of illustration, in which Figure 1 is a side elevation of a tie tamper,

Figure 2 is a sectional view taken on line 11-11 of Figure 1, a

Figure 3 is an illustration of the tamper bar,

and I Figure 4 is a wiring diagram showing the operation of the invention.

Referring to Figure 2, a removable slotted bushing I is provided of non-magnetic stainless steel which guides the magnetic piston or striking element 2 which reciprocates therein. Piston 2 is made of silicon nickel steel having a striking extension 3 at one end which is tipped with a hard non-magnetic metal such as cobalt-chromium-vanadium alloy known as Stellite." The piston 2' has four slots 4 approximately inch wide and inch deep to reduce waste currents therein. A cylinder 5 is provided in which the bushing l is removably located, and end laminations 8 and 1 are circumferentially arranged about -the cylinder 5 on flat portions 8 provided on its outer surface and are secured thereto by welding or in any other suitable manner. The end laminations 6 and I have pole tips 9, H), II and i2 in openings I3 in the barrel 5 flush with the inner surface. The operating winding of the hammer comprises four coils i4, l5, l6 and I1 connected in series, the inner coils i5 and I6 being of copper wire and the outer coils I4 and I1 being of aluminum wire or an aluminum alloy wire. Metallic separators or washers I8, and 2| limit longitudinal expansion, brace the windings against coming loose and conduct heat rapidly to the outside surrounding case 22 which is made of high silicon low carbon steel of high electrical resistance which tends to diminish eddy current losses. The aluminum and copper coils provide maximum heat dissipation and materially reduce the weight of the coil structure.

A bottom cover 23 has a bore 25 surrounded by a flange 26 and the barrel 5 and a bushing l extending from the laminations are received in the bore and abut the flange 26. A top cover 21 has a bore 28 to receive the extending barrel 5 and bushing I therein. Cover 22 has bevelled edges received by the bevelled flanges 30 of the bottom cover and a washer 3! at the top cover and tie rods 32' extend through holes in the lugs 33 and 34 of the top and bottom covers.

A core stop or buffer 35 comprises a cylindrical body extending into bushing l with a slight clearance. Preferably the core stop is composed of a solid compressible material selected from the group comprising polymerized butadiene and its homologues and substitution products, for example Neoprene" which I believe to be polymerized chloro-2-butadiene-'1,3 and Cogene" or Ameripol sold by B. F. Goodrich Tire & Rubber Company, which I believe to be a copolymer of butadiene or its homologues and acrylonitrile. This core stop has a flange 38 which abuts a shoulder 31 on the top cover and engages the end of bushing l and cylinder 5. Spacers 38 and 40 have holes therein through which pass the tie rods 32 and spring leaves 4| are held between spacers 38 and 40 and clamps 42 and 43. A hole 30 is provided in butter 35 which passes through springs 4| to allow the escape of air from the bushing I, which otherwise would interfere with the operation of the apparatus. The circulation of air also assists in cooling the bufier. A handle structure 44 has holes therein to receive the tie rods 32 and nuts 45 at the top end and nuts 46 at the bottom hold the parts in assembled relation. The handle structure 44 has a laterally extending offset handle 41 and a handle 48 at the end of extension 50 which'is braced by posts 5|.

At the lower end of the apparatus a bushing 52 having a hexagonal bore 53 therein is received in the bushing I and has a flange 54 abutting the flange 25 of bottom cover 23. A tamper bar 55 has a non-circular end 58 received in the guide bore 53 to prevent the bar from turning and a flange 51 on the tamper bar is received in a recess 58 in an extension 50 of the bushing 52. The tamper bar has a blunt end 50.

The bushing 52 is held in place between the cover 23 and a flanged housing secured to the cover by bolts 62. he split bushing 53 has a flange 64 received in e bore 05 of the housing BI and has a hub 66 extending into recess 58, the flange 64 abutting the end of extension 60. A circular hole 61 in bushing 53 receives the tamper bar 55 with a sliding fit. The hub 60 of the bushing limits outward movement of the flange 51 on the tamper bar. A washer seats against flange 04 and a spring 10 abuts a washer 68 at one end and abuts washer 1| which in turn abuts flange I2 of a round split bushing I3 seated on a shoulder I4 at the end of housing 0|. A retaining plate I5 overlies the bushing I3 and is held in place by the bolts and nuts and II, the tamper bar 55 passing through bushing I3. This construction enables ready removal of the tamper bar by disconnecting housing 0| from the motor bottom cover 23.

An operating switch case 00 mounted on the cover 21 carries a turn switch 0| making contact across terminals 03 and 02 to which are connected wires 84 and 05. Wire 05 connects to one end of coil l4 and the end of coil I1 is connected with wire 05. Wires 00 and 04 pass through extension 81 of the top cover, through strain relief hose 00 which is clamped by a suitable clamp 90 to the extension 01, and through the cable 0| which may be of any desired length to a plug 32 which preferably is of the two point weatherproof bayonet joint type.

The preferred electrical circuit for operating the apparatus is shown in Figure 3. Current from an alternating current generator, which preferably is a two phase generator, diagrammatically indicated at 05 and which is excited by exciter 95, is conducted by common return wire 81 to terminal 90 of a line switch I00, and wires IM and I02 conduct current to terminals I03 and I04 of said switch. When the switch I00 is closed one current impulse of one phase passes by wires I05 and I05 to the anode I01 of a thermionic rectifier tube I00, from cathode H0 and by wire III to a terminal II2 of a'line receptacle II3. Common return terminal H4 is connected by wires 5 and H0 to common switch terminal 93.

The next current impulse of the same phase passes from terminal 30 by wire H0 and III to common receptacle terminal H4 and from receptacle terminal Ill and wire H0 to anode H3 of rectifier I2I, thence by cathode I22 and wire I05 to terminal I04. Similarly, one current impulse of the second phase is conducted by wires I23 and I24 to the anode I25 of a rectifier tube I26, thence by a cathode I21 and wire I20 to terminal I30 of receptacle I3I and from common receptacle terminal I32 by wires I33 and H0 to common terminal 30. The next current im ulse passes from terminal 08 by wires H0 and I33 to receptacle terminal I32 and from receptacle terminal I35 by wire I30 to anode I31 of the tube rectifier I30, thence from cathode I33 and wire I23 to switch terminal I03. The four rectifier tubes derive heating current from a transformer comprising pairs of coils I4I, I42, H3 and I44 supplied by wires I45 and I40 through switch I".

The receptacles H3 and I3I are connected by a cable about 250 feet long carrying wires I40, I50 and I5I, and wires I52, I53 and I54 which terminate at one end in a suitable plug to be plugged into receptacles H3 and I3I. At their other ends the cables carry units shown diagrammatically at I55 and I55 having two terminal receptacles I51, I50, I00, IOI, etc. Any desired number of such two terminal receptacles may be provided, depending on the number of tampers to be operated from the circuit. Eight such receptacles are shown. The plug 32 of a tamper unit can be inserted into any one of the receptacles and when two tampers are so connected, for example, to receptacles I00 and IOI, one rectified wave of one phase passes through the coil I02 which diagrammatically represents a tamper, and the other rectified wave of the same phase passes through coil I03 which diagrammatically represents the other tamper.

Preferably, the tubes are cooled by an electric fan I05 or other cooling device deriving its current from the exciter 00.

Referring to Figure 2, each time the piston 2 moves to the lower end of the barrel I it strikes the end 50 of the tamper bar 55. When the aparatus is raisal from the work the flange 00 of the tamper bar engages the bushing 03, and

' the spring I0 bearing against bushing 03 is tuned to keep the piston in synchronism with the current impulses under non-working conditions. When the tamper bar rests on the ballast the bar is in its upper position, and when the piston strikes the bar it permits a forward movement of the bar against the ballast, pushing the ballast ahead of it. The next current impulse passing through the coil pulls the piston 2 upward, causing it to strike the buffer 30. In designing the buffer, it should be so dimensioned that its resistance to compression is enough to maintain the piston within certain limits of its workin stroke, so that the piston will remain synchronized with the rectified wave impulse. Synchronization also depends on the length of the stroke of the piston, its weight and the electromagnetic energy supplied by the coil. For example, I prefer to use a piston weighing about 4 to 4% pounds, having a stroke between 3% and 4% inches and delivering about 600 to 850 blows per minute, and preferably about 750 per minute against the tamper bar. Where P is the current frequency the number of blows delivered per minute is F/2x60. For example, operating from a volt alternating current source of 25 cycle primary current at an energy input of 900 watts, the number of blows would be 25/2x60=750 per minute.

The synthetic rubber substitute core stop is of particular advantage in that it has a longer life than a metal spring. is resistant to heat, oil or grease, its use reduces the weight of the tamper and the number of parts required and thus reduces the cost of manufacture. It also climb nates a large amount of noise, which is important in railway work where excess noise prevents the workmen from hearing the approach of a train. If desired, the spring 0| may be replaced by a suitable member made of Neoprene," "Ameripol," or any other suitable polymerized butadiene type of syntheic rubber substitute.

The system herein disclosed moves the free piston in both directions by current impulses of the same polarity with a considerable period of zero energy between current impulses, the current impulses'being obtained by a rectifier from a single phase alternating current applied to one-Mm.

continuous winding to produce a pulsating magnetic field, and has a dead center point which occurs when the approximate center of the piston is at the approximate center of the air gap,

ratus shall be self-starting, and in order to overi come the inertia of the piston, the buffers or resilient members at the ends of the piston stroke have a natural period oi vibration the same or greater than the number of blows struck against it by the piston. Preferably a, higher natural period is used to be certain that the full inertia of the piston is overcome so that the piston is moved away from the end of its stroke rapidly enought to be caught by the magnetic field. As the present apparatus is always in non-horizontal position during operation, the dead center point always will be overcome either by the weight; of the piston or by the rebound of the buffer members. This construction is especially desirable in an apparatus of this type, in that only one winding need be employed to move the piston in both directions, thereby providing a greater length of stroke with a shorter winding. However, our invention is not restricted to this type or tool and may be applied to any of the various known types of percussion tools, as for example, the two coil structure shown in Patent No. 1,723,830, issued August 6, 1929, to Carl S. Weyandt.

The line switch I preferably is electromagnetically controlled from a remote point to start and stop the tampers. The remote control mechanism comprises a solenoid I81 having an armature I88 connected to contact switch member I10. Current from terminal I03 passes by wire I1I to terminal I12 of remote control switch member I13 and when starting switch I14 is closed between terminals I12 and I14 the current continues by wire I15 across switch terminals I16 and I11 closed by switch member I18 and by wire I80 through solenoid I61 to close switch member I10, and continues by wire I 8I to common terminal 98. Actuation of armature I68 closes switch I82 so that when switch member I14 is released by the operator and opened by a spring (not shown) the current continues to flow from terminal I04 and wire I83 through switch I81 and by wire I84 through switch I18 and by wire I80 through coil I61 to terminal 98, thus holding switch member I closed. To open the main circuit switch member I18 is moved to open position, thus breaking the circuit through solenoid I61 and allowing a spring (not shown) to move switch members I10 and I82 to open position. A spring (not shown) closes switch I18 when released by the operator.

This arrangement of remote control is of particular advantage in tie tamping as it enables the watchman to warn the workmen against approaching trains by opening the line switch and stopping operation of the tampers, and after the train passes he can automatically start the tampers operating. In this way, the output of the stantially at the middle of the member, a piston adapted to reciprocate in said guide member, coil means surrounding said laminations, means to supply substantially spaced successive current impulses of like polarity to said coil means to provide a single pulsating magnetic field to reciprocate said piston, a tool adapted to be struck by said piston at one end of its stroke, resilient means providing a stop for said tool, and a butler selected from the group comprising polymerized butadiene and its homologues and substitution products or copolymers thereof with unsaturated compounds at the opposite end of said tubular member, said resilient means and buffer being adapted to maintain the piston in synchronism with the pulsating magnetic field.

2. In a percussion tool, a tubular guide member, electromagnet laminations surrounding said member, a piston adapted to reciprocate in said guide member, coil means surrounding said laminations, means to supply current impulses to said coil means to provide an actuating magnetic field to reciprocate said piston, a tool adapted to be struck by the piston at one end of its stroke, resilient means providing a stop for said tool and a buffer selected trom the group comprising polymerized butadiene and its homologues and substitution products of copolymers thereof with unsaturated compounds at the opposite end of the tubular member, said resilient means and buffer being adapted to maintain the piston in synchronism with the actuating magnetic field.

3. In a percussion tool, a tubularguide member, electromagnet laminations surrounding said member, a piston adapted to reciprocate in said guide member, coil means surrounding said laminations, means to supply current impulses to said coil means to provide an actuating magnetic field to reciprocate said piston, a tool adapted to be struck by the piston at one end of its stroke, a buffer selected from the group comprising polymerized butadiene and its homologues and substitution products of copolymers thereof with unsaturated compounds at the opposite end of the tubular member, said tool and buffer being adapted to maintain the piston in synchronism with the actuating magnetic field.

4. In a percussion tool, a tubular guide member, electromagnet laminations surrounding said member, a piston adapted to reciprocate in said guide member, coil means surrounding said laminations, means to supply current impulses to said coil means to provide an actuating magnetic field to reciprocate said piston to deliver six hundred or more impacts per minute, a tool adapted to be struck by the piston at one end of its stroke, and a buffer selected from the group comprising polymerized butadiene and its homologues and substitution products of copolymers thereof with unsaturated compounds located adjacent the end of the guide member opposite the tool and having air escape means, said tool and buffer being adapted to maintain the piston in synchronism with the actuating magnetic field.

5. In a percussion tool, a tubular guide member, electromagnet laminations surrounding said member and providing a dead center air gap substantially at the middle of the member, a piston adapted to reciprocate in said guide member, coil means surrounding said laminations, means to supply substantially spaced successive current impulses of like polarity to said coil means to provide a single pulsating magnetic field to reciprocate said piston, a tool adapted to be struck by said piston at one end of its stroke, resilient means providing a stop for said tool, and a butter oi polymerized chloro-butadiene at the opposite end of said tubular member, said resilient means and bufier being adapted to maintain the piston in synchronism with the pulsating magnetic field.

6. An apparatus comprising a reciprocating piston, electromagnetic means for reciprocating said piston to deliver six hundred or more impacts per minute,-a tool at one end of the stroke of the piston located to be struck thereby, and a bufler of synthetic rubber substitute at the other end of the piston stroke located to be struck thereby.

7. In a percussion tool adapted to be operated in non-horizontal position, a tubular guide member, magnet laminations surrounding said member and providing a dead center air gap substantially at the middle of said member, a free piston adapted to reciprocate in said guide member, coil means surrounding said laminations, means to supply substantially spaced successive current impulses of like polarity to said coil means to provide a single pulsating magnetic field to reciprocate said piston, a tool adapted to be struck by said piston at one end of its stroke, resilient means providing a stop for said tool, and a buffer at the opposite end of said tubular member, said resilient means and buffer being adapted to maintain the piston in synchronism with the pulsating magnetic field.

8. An apparatus comprising a reciprocating piston, means for reciprocating said piston to deliver six hundred or more impacts per minute, a

tool at one end of the stroke of the piston located to be impacted thereby, and a bufler of polymerized butadiene type of synthetic rubber substitute at the other end of the piston stroke located to be impacted thereby.

9. An apparatus comprising a reciprocating piston, means for reciprocating said piston to deliver 600 or more impacts per minute, a tool at one end of the stroke of the piston located to be impacted thereby, and a bufi'er of copolymerized butadiene and its homologues with acrylonitrile at the other end of the piston stroke located to be impacted thereby.

10. In a percussion tool, a tubular guide member, electromagnet laminations surrounding said member and providing a dead. center air gap substantially at the middle of the member, a piston adapted to reciprocate in said guide member, 0011 means surrounding said laminations, means to supply substantially spaced successive current impulses of like polarity to said coll means to provide a single pulsating magnetic fleld to reciprocate said piston, a tool adapted to be struck by said piston at one end of its stroke, resilient means providing a stop for said tool, and a bufler of the polymerized substituted butadiene type at the opposite end of said tubular member, said resilient means and butter being adapted to maintain the piston in synchronism with the pulsating magnetic field.

ii. In a percussion tool, a tubular guide member, electromagnet laminations surrounding said member and providing a dead center air gap substantially at the middle 0! the member, a piston adapted to reciprocate in said guide member, coil means surrounding said laminations, means to supply substantially spaced current impulses of like polarity to said coil means to provide a single pulsating magnetic field to reciprocate said piston, a tool adapted to be struck by said piston at one end oi its stroke, resilient means providing a stop for said tool, and a butter of copolymerized butadiene and its homologues with acrylonitrile at the opposite end of said tubular member, said resilient means and bufler being adapted to maintain the piston in synchronism with the pulsating magnetic field.

CARL S. WEYANDT. EDW. J. MISSIEN.

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