US1492389A - Wood grinder - Google Patents

Description

P. PRIEM woon GRINDER April 29, `1924.

s sheets-sheet 2 Filed Feb. 24 1923 INVENTOR Fnufp PR/Em ATTORNEYS April 29, 1924; 1,492,389

P. PRIEM wooD GRINDER Filed Feb. 24, 1923 5 Sheets-Sheet 3 Ff@- 5f AlNvENToR Pflug. Pfr/EM.'

v BY

ATTORNEYS 40 chain 14 running over one of the Patented Apr. 29, @924.

UNITED STATES 1,492,389 PATENT oEFicE.

PAUL Param, or HEIDENHEIM, GERMANY, AssrcNoa 'ro MEEICAN vorrir coN'racr COMPANY, INC., or NEW YoEx, N. Y., A conronArIoN or NEW YoEx.

WOOD GRINDER.

Application tiled February 24,1923. Serial No. 621,117.

To all whom it mag/'concerm Be it known that I, PAUL PRTEM, a citizen of the Republic of Wurtemberg, Germany, residing at Heidenheim on der Brenz,

Germany, have invented certain new and.

matically iegulatin t-he pressure against the grind stonentha-t t e latter may be driven vat a substantially constant load and speed.

This regulation isaccoinplished according to the invention, through means responsive to the varying demand on the driving motor to maintain the stone at constant speed.

The underlying thought is susceptible of embodiment in various forms of equipment,

some of which are illustrated in the accompanying drawings, in which- Fig. 1 is a more or less diagrammatic broken side elevation of a wood grinder installation in which my invention is embodied in one form; and l Figs. 2, 3 l4 and 5 are similar views of different embodiments of the invention.

Referring to Fig. 1, I have indicated at 5 an electric motor of constant speed type,

s0 which drives the grind stone' 6 through any suitable operating connection, such as a belt lor chain 7. Associated with the grind stone is a series of press lungers 8, each working in its independent eed chamber 9 to force a charge of wood blocks 10 a ainst the stone. Each of the plungers is f forward by a pinion 11 engagin the rack 12 on the stem of the lunger an driven throu h a chain connection 13, which in turn is riven b a sproc et wheels 15. The chain 14 is driven from the pinion 16 on the shaft of a worm wheel 17,

with which meshes the worm 18 on the spindle 19 of a press feedmotor 2O of the 46 variable speed type. Current is led to the ress feed motor 20 through a rheostat 21, aving a series of contacts'22 over which travels an arm 23, pivoted at 24 and counter-weighted at 25. i lSecured to the lever23 5o is the movable core 26 of a solenoid winding 27 amnged in the circuit 28 of the stonedriving motor 5.'

It is obvious that if. the load on the grindV stone 6 varies, incident to the character of` u the wood billets l10 which are forced against lrheostat v21 arranged in the circuit of the ,the stone by the presses, a variation of current in-put to the grind-stone drive motor 5 results, since the stone is driven at constant speed. The consequent variation in the current flow through the solenoid winding 27, influences the position of the solenoid core 26. This displacement of the solenoid shifts the contact arm 23 across the rheostat contacts 22, and a greater or less resistance is thus interposed in the circuit of the ress feed motor 20. As a consequence, the rive of the press plungers 8 is accelerated or retarded, and the load on the stone is thus automatically maintained substantially constant. The speed of the stone is thus also maintained substantially constant.

A modified arrangement in which the same result is accomplished is illustrated in Fi 2, in which the drive of the stone 6 throug the belt or chain 7 is taken from the turbine 29.` The driving belt 7 o crates a centrifugal governor 30, to a col ar 31 of which is connected one arm of the Contact arm 32 which ,travels over Lthe contacts 22 of the feed motor 20 for the ress. The latter is here indicated as of different type. Thus the feed motor spindle 19 is provided with two worms 33 and 34, which meshwith worm wheels 35 and 36 on the shafts 37 and 38 of the gears which drive the press chains 39 and 40. The latter are arranged at o posite sides of the hop er 41 and engage t e opposite sides of the cliarge of wood blocks 42 and feed the latter against the vstone 6.

The operation of this installation is analogous to that first described. When the frictional drag of the wood blocks on the grind stone variesy the speed of the turbine 29 and the governor 30 is corres ondin ly affected. The contact arm 32 is t us shifted up or down on the contacts of the rheostat 21 and the current suppl to lthe press feed motor 20 is increased or ecreased, thus acceleratin or retarding the feed chains 39 and 40. Tiie load on the stone is thus maintained substantially constant, and a drive of the stone at substantially uniform speed attained. f

In the construction shown in Fi 3 the arent of the press and its eed motor 20 is substantially identical with that just -described The grind stone 6, however, is

.driving fluid or gas crank shaft 44 of a reciprocating engine 45 which may be of an suitable type. The mitted to or exhausted fromy the cylinders of the engine 45 may be led through a pipe 46 to which opens a branch 47 leading to the pressure box 48. Working within the latter is a spring-opposed piston 49the stem 50 of which is connected to one arm of the contact lever 51 which travels over the contacts 22 of the rheostat 21 arranged in the circuit of the feed motor 20. As the load on the stone 6 varies, the pressure head of the or fluid admitted to or from the cylin ers of the driving'A engine 45 varies, and this variation is communicated to the pressure box 48 throu h the branch 47. The piston 49 is there ore shifted in one direction or the other, and correspondingly shifts the position of the contact lever 51 on the rheoetat 21. The speed of the feed motor 20 is thus controlled. Y

Still another embodiment of my invention is illustrated in Fig. 4, in which the drive of the stone 6 is similar to that shown in Fig. 1. The press lungers 8 are also of the type shown in i0. 1, but the drive of the gear 17, instead ofe being taken from an electric motor 20, is taken, in this modification, through a belt or chain 52 passing around a driving pulley or r 53 on the shaft 54 of a turbine 55. T e gas or fluid which drives the turbine 55 enters through the` ipe 56 in which is arranged a valve 57, t e stem 58 of which is connected to the solenoid core 59, which, as in-Fig. 1, is hung from one end of an arm 60 pivoted at 61 and counter-weighted at 62. The winding 63 of the solenoid is arranged inthe circuitof the stone-driving motor 5.

The operation is also analogous to those above described. As the load on the stone varies, with consequent variation in the current in-put to the motor 5, the solenoid core 59 rises and falls, and thus varies the position of the valve 57 which controls the flow to the press-feed turbine 55. The feed of the press is thus altered, and the drive of the stone at substantially constant speed is secured. v

A further embodiment of m invention is illustrated in Fi 5, in whic the stone 6 is driven, as in igs. 1 and 4, from a constantl speed electric motor. The press is of the type shown in Figs. 2 and 3, com

prising feed chains 39 and 40 operated through gears 35 and 36 and worms 33 and 34 on a spindle 19. The latter, however, is driven according to the present modification from a rotary pump 64 operating as a fluid motor. This pump, preferably of y the toothed wheel type, drives the pulley 65,

on which runs the chainor belt 66 to the pulley 67 on .a gear shaft transmitti motion to the bevel gear 68 at one' end 1,4.ea,see

the worm'shaft 19.l '111e Huid which drives the rotary pump 64 is delivered thereto from a second pump 69 of the same or different type, the pulley 70 for operating which is driven from the constant speed electric motor 5 through a chain or belt 71, although the pump may be driven from a se arate source of power. The iiuid upon which the pump 69 operates is contained in a tank 72 and 1s delivered by the pump 69 to piping 73, through which it passes to the motor pump 64 to actuate the latter which discharges the fluid again to the tank 72.

Arranged in the piping 73 is a control valve 57, the stem 58 of which is connected to the cone 59 of the solenoid winding 63 arranged in thecircuit of the motor 5.v As in the construction shown in Fig. 4, the solenoid is attached at its upper end to the lever 60 pivoted at 61 and counterweighted at 62. i As above explained, the current demand of the constant speed motor 5 varies with the load imposed upon the stone 6 by the feed chains 39 and 40. The fluctuation of current varies the position of the solenoid core 59'and thus alters the position of the valve 57 so that more or less duid is delivered by the pump 69 to the pump 64 which operates the feed chains and thus varies the load upon the grind stone 6 in accordance with the current demand upon the motor 5.

Various other embodiments of m invention will readily occur to those dealing with the problem, without departing from what I claim as my invention.

I claim- 1. In a wood grinder installation, a grind stone, a motor for driving the same,.a pre for mechanically feeding a charge of wood blocks against the stone, a variable feed rotary motor for advancing the re, and means responsive to the wer emand on the stone-driving motor or re lating the e'ort of the variable spee press-feed motor to maintain the pre load on the stone substantially constant.

2. In a wood grinder installation, a grind stone, a motor for driving the same, a press for mechanically feeding a charge of wood blocks against the stone, a variable feed rotary motor for advanacing' the press, a membermovable with and subject to fluctuations in the power supply to the driving motor incidental to the drive of the stone at constant spleed, and means operatively associated wit said movable member for regulating the. power in-put to the variable speed press-feed motor to maintain the press load on the stone subdantially constant.

j 3. In a wood grinder installation, a grind stone, a motor for driving the same, a pres for mechanically feedinga char of wood blocks against the stone, a gear for advancing the rees, a variable speed electro-motor for driving the feed ar, and means for controlling the'speed o the variable speed electro-motr to maintain sub- 5 stantially constant the load on the grind stone.

4. In a wood grinder installation, a grind stone, a motor for driving the same, a press for continuously feeding a charge of wood f blocks against the stone, a feed gear for ad r 10 vancing the ress, a variable speed electro motor for driving the feed gear, and means for controlling the speed of the variable `speed electro motor to maintain substantial` ly constant the load on the grind stone. 15 In testimony whereof I have signed my name to this specification.

PAUL PRIEM.

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