US1521292A - Molding apparatus - Google Patents

Description

Dec. 30, 1924.

J. 5. HARRISON MOLDING APPARATUS Fi led May 1, 1924 2 Sheets-Sheet 1.

"fill I Dec. 0, 1924. 1,521,292

. Ji s. HARRISON MOLDING APPARATus Filed May 1, 1924 material into block form.

Patented Dec. 30, 1924.

UNITED STATES PATENT OFFICE.

JOHN STANLEY HARRISON, OF LONDON, ENGLAND, ASSIGNOR T0 MACNAIB STRATI- FIED COAL LIMITED, OF LONDON, ENGLAND, A BRITISH COMPANY.

MOLDING APPARATUS.

Application filed May 1,

is a specification.

This invention relates to molding apparatus for consolidating powdered or plastic In a machine of the type to which this invention refers top- .pressure is applied to the material in the mould by a weighted plunger and in the formation. of successive blocks mechanical means operate alternately to raise the plunger clear of the mould when consolidation of a block is completed and then to release it when the next block is to be formed.

The main'object of the present invention is to provide means for accurately timing the lift and release of the pressure-plunger.

The present invention provides in molding apparatus of the type specified above, the combination of two mechanisms operated in step one being an elevator which is actuated periodically to lift the pressureolun er to a certain height and then to release it, and the other being a holding mechanism ope 'ative to engage the plunger when freed by the elevator, to support it for a predetermined time in its raised position and then to release it.

It will be appreciated that between each application of pressure aninterval is requilted for the ejection of the finished block and for the next filling operation. This interval and also the necessary dwell of the plunger in its lower or operative position cannot satisfactorily be controlled by a single mechanism, but by the provision according to this invention of two mechanisms as above described any desired dwell of the plunger in both upper and lower positions can readily be obtained.

In one form of theinvention the elevator mechanism for the pressure-plunger is operatively connected through a clutch with a continuously-running driving member and means actuated by or in step, with said driving member operate in succession to engage the clutch, maintain it engaged for a time sufiicient to enable the elevator to lift the plunger to the desired extent, and then to free the clutch. The holding mechanism for the plunger may take the form of a 1924. Serial No. 710,255.

spring pressed detent arranged automatically to engage a stop on the plunger when the latter is in its raised position combined with a trip device actuated in step with the aforesaid clutch-control means for the elevator to free the detent from engagement with the plunger-stop after a predetermined interval.

Conveniently the detent-releasing device and the clutch-control means are actuated by cams carried on the same shaft, which shaft is driven from the continuously-running member which provides the elevator drive.

An example of the invention will now be described with reference to the accompanying drawings, in which Figure 1 is a front (part sectional) elevation of the upper part of a molding machine to which the invention is applied;

Figure 2 is an end View of the upper portion of Figure 1, parts being broken away in order to show clearly the mechanism which controls the lift and release of the pressure-plunger, and

Figure 3 is a top plan view (largely dia grammatic) of the machine shown in Fig ure 1. f

Like reference numerals parts in the several figures.

The apparatus illustrated is a two-unit machine designed for the manufacture of fuel briquettes. The moulds 5 are arranged in pairs,- one pair operating in conjunction with each pressure-plunger 6, and the two mould-pairs are coupled together and movable laterally as a single unit. hen one mould of each pair is under the corresponding plunger the companion mould is in a sidestepped position. Ejecting devices are arranged to operate in conjunction with the sidestepped moulds to eject the finished blocks therefrom. The bottom of each mould is formed as a movable pallet 7 to which a rapid reciprocatory movement in a vertical direction and of comparatively short throw. is imparted while the mould is under the plunger. The consolidation of the material in the moulds is efiected partly by the application'of top-pressure thereto by the dead-weight plungers 6 and partly by the tamping or jigging action of the bottom pallets.

The general sequence of operations is as follows indicate like Ill) The material to be consolidated (e. 9., coal-dust mixed with a binding medium such as bitumen) is fed in measured charges into the moulds under the plungers, the reciprocating bottom pallets are set in motion, and top-pressure is applied by the plungers. After a predeterminedinterval the plungers are raised, the reciprocation of the bottom pallets is stopped and the moulds are moved laterally thus bringing the pre- .viousl y "side-stepped moulds (which are empty) under the plungers. The next filling operation proceeds on the fresh moulds while the finished blocks are ejected from theside-stepped ones. The plungers 5 are again allowed toifall and the same sequence oflop'erations is repeated. The general features of the apparatus so far described 'do-notform part of the present invention, but they are mentioned in order that the necessity for the accurate timing and release of the pressure-plans gels (with which this invention particularly deals) ina contmuously-operatmg machine of this kind may be appreciated;

Each plunger 6 is connected by springpressed bolts 8 to an upper dead-weight 9 which in turn carries' a vertical rack-bar 10. "plunger 6 and weight 9 provides a more re- The spring connection between the silient'top pressure than could be obtained with a simple gray]ty-controlled. plunger. The weights 9 are guided for vertical move- "ment by upright rods 11 and the rack-bars pass upwardly. through apertures in framemembers 12 which are supported by columns 13 from the base of the machine.

'Pinions let meshwith the teeth of the rackcontinuation thereof is a constantly rota-ting shaft 18 which is driven from the base of the machine by another shaft (not shown) constituting the continuously-running driving member hereinbefore referred to. Connection between the shafts 17 and 18 is made by means of auclutch 19,- the throwing in and out of which is controlled by a'slidingr collar 20 (see Figure 2) which is movable against the action of a spring 21 t-0 engage the clutch and moved in the opposite direction'by said spring to disengage 1t. lvlovement of the-sliding collar is in turn controlled by-a forked lever 22 pivoted-at itslowerend for swig-ingmovement about a fulcrum rod 23 extending shaft 17.

,arms of the lever 22 are cod-pieces 24 which engage in a circumferential channel in theat right-angles to the axis of the clutch Extending inwardly from the collar 20. The upper end of the lever 22 carries a roller 25 co-operat'ing with which IS a cam 26 mounted on a cam-shaft 27 wh h extends parallel with and abQ Q the fulcrum rod 23 and constantly rotated through bevel gearing'28 from the continu ously-running drivmg member hereinbefore re'ferredzto. On each revolution of the-camshaft the cam'26 engages the lever 22 and of which engage under projecting strips 30 secured to the sides of the rackbars 10.

V The .detents are resiliently pressed up to the racks bysprings 31 bearing against fixed brackets 32 and located in position'hy pins 33, 34 secured to the brackets and detents respectively. The two detents are coupled together by a connecting rod .35 ',(see Figure 3) which extends: parallel with the 1 clutch shaft 17. Movement of the rod 35 to the left frees the Tdetents from engage V V ment with the stripsBO andyprovided the clutch 1-9 is out, allowsthe racks,.and with them the weights {land plungers .6' to descendi During thejfall; of the racks the pinions 14, gearinglfi and shaft 17 run. free- The release .of thie detents is controlled by aforked lever 36"mounted on the fulthe lever 36 carries a roller 38 co-opera'ting Wl'lTll a cam 39 on the cam shaft 27 which controls the engagementiand disengagement of the clutch 19. "Vhen the cam 39 engages the roller 38 it swings the rlever' and the rod 35 to the left and so frees the rack detents and: allows the pluhgers to descend. V-Vhenthe cam moves pastfthe roller the springs 31 press the detents against. the

sides of the strips 30and when-the racks; V are again raised the strips overrun the detents and the latter positlon.

reassnn e their locking The plungerglift and release apparatus described above operates in the following 1 manner 2-: is y V V Assuming"theplungers to be in the lfllSECl position the cam 39'first comes .into action to release the reel; deten-tsand' the plungers fall. After predetermined interval, ,d'e

pending uponthe angular spacing between the cam 39 andthe clutch-control cam 26, the latter engages and throws over the clutch lever 22 and the rack pini-ons are thereby coupled to the continuously drive shaft 18; The shape of the cam 26is such that it maintains the clutch in engagement V v be moved to the left thus allowingthe clutch 'just suflicientlylong to enable the racks to limit of their travel the ends of the strips 30 ride past the detents 29 and the latter automatically springinto the locking position. Thus when the clutch is released the racks are taken in charge by the detents and prevented from falling. On the next revolution of the cam shaft the detent-release cam again comes into operation and the plungers descend into the moulds. The cams 26 and 39 are so angularly set and the speed of the cam shaft is such that the plungers are maintained in the raised position for a period suflicient to accommodate the side-stepping of the moulds, the filling of the empty moulds which are brought under the plungers, and any other operations -which may be necessary between each descent of the pressure-plungers.

In the above example the period during which the clutch. 19 is engaged depends upon the duration of engagement between the cam 26 and the clutch-control lever 22.

' In'an alternative arrangement the release of the clutch may be timed by the engagement of the rack detents. That is to say while the cam 26 is arranged to throw the clutch into engagement, the disengagement of the latter may be effected by means interconnecting the detent rod with the sliding collar of the clutch. The interconnecting means may conveniently take the form of a finger (not shown) projecting laterally from the connecting rod 85 so that when the rod is moved to the right 0., when the detents are overrun by the rack steps 30) the finger will engage with the clutch collar or the control lever 22 or a part attached to either and so move the clutch collar into the free position. When the de tents are next released the trip finger will to be thrown in when the clutch cam 26 next comes into operation.

If desired the trip finger may be used as a safety device in conjunction with a clutch, the engagement or disengagement of which is normally effected solely under the controlof the clutch cam. Thus in this case should the clutch spring such as 21, which is normally relied 011 to throw out the clutch, fail to act the trip linger will come into play and free the clutch.

It will be understood that the apparatus as described above may be modified in many -ways without departing from the scope of the invention. For example any other convenient elevating mechanism may be employed in place of the rack-and-pinion mechanism used in the particular example illustrated. Again the holding mechanism which is ope 'ative to engage the plunger when freed by the elevator may take forms other than the spring-controlled detcnt described herein.

1 claim:

1. In molding apparatus of the type specified the combination with a pressure-plunger of an elevator mechanism for said plunger, meansperiodically to actuate said elevator so as to lift the pressure-plunger to a certain height and then to release it, a holding mechanism to support the plunger in the raised position, means actuated in step with the operation of the elevator to engage said holding mechanism with the plunger when the latter is freed by the elevator, to mainta'n it engaged fora predetermined time and then to release it.

2. In molding apparatus of the type specified the combination with a pressure-plunger of an elevator mechanism for said plunger, a continuously-running driving member, a clutch movable to couple said driving member with the elevator, means operated in. step with said driving member periodically to engage the clutch, maintain it engaged for a predetermined time suflicient for the elevator to lift the plunger and then to free the clutch, a holding mechanism to support the plunger in the raised position, and means actuated in step with the clutch-control means aforesaid to engage the holding meclian'sm with the plunger, when the latter is freed by the elevator, to support said plunger for a predetermined time in its raised position, and then to release it.

3. In molding apparatus of the type specified the con'ibination with a pressure-plunger of an elevator mechanism for said plunger, a continuously-r11nn ng driving member, a clutch movable to couple said driving member with the elevator, means operated in step with said driving member periodically to engage the clutch, maintain it engaged for a predetern'iined time sufficient for the elevator to l ft the plunger and then to free the clutch, a resiliently-controlled detent automatically operative to engage the plunger when in the raised position and to hold it in said position, and a trip device actuated in step with the aforesaid clutch-control means to free the detent from engagement with the plunger after the latter has been in the raised position for a predetern'iined interval.

4. In molding apparatus of the type specified the combination with a pressure-plunger 'of an elevator for said plunger, a continuously-running driving member, a clutch movable to couple said driv'ng member with the elevator, a resiliently-controlled detent automatically operative to engage the plunger when the latter is raised and to support it in the raised position, a trip device movable to release the detent from engagement with the plunger, and cams rotated in step with the continuously-running 7 member and arranged to operate the clutch ously-running driving member, a clutch movable to couple said driving member with the elevator, a cam operated from the continuously-running member aforesaid so as successively to engage the clutch,1uaintain it engaged for a predetermined time "suflicient for the elevator to raise the plunger and then to fi'ee saidclutch, a resiliently-controlled detent automatically op' erative to engage the plunger when in the raised position and to support it inthis position, anda trip device cam-operated fromthe eontiniiously-running member to free the 'detent from engagement with the plunger and to support it in the raised'position, a. trip-device movable to release the detent after a predetermined interval.

6; In molding apparatus of the type speci fled the combination with a pressure-plunger of an elevator mechanism for said plunger, a eontinuously-running driving mein her, a clutchmovableto couple said driving member with the elevator, a resiliently-coir trolled detent automatically operative to engage-the plunger when the latter is raised from en a ement with the )lunqerand a cam-shaft driven from the continuously. running member aforesaid and carry ng two cams one co-operating with a follower which. is opcratively connected to the detent tripdeviee and the other with a follower operatively connected to the clutch aforesaid, said cams being so spaced apart angularly as to operate on their respective followers in such sequence and at such intervals as to provide a dwell of the pressure-plunger in both up 7 per and lower positions.

7. In molding apparatus of the type specified the combination with a pressureplunger of a 'a-ck-and-pinioii elevator mechanism for the said plunger whereof the rack is secured to .the plunger, ai continuously- 7 running driving member, a clutch movable to couple said driving member with the rack pinion, means operated instep with said driving member periodically to engage the.

clutch, maintain it engaged for a predetermined time suflicient for the pinion to lift the rack and plunger, and then to free the clutch, a resiliently-controlled detent auto- Imatically operative to engage a stop on the rack when the latter is raised and to support the rack and plunger .in the raisedposition, and a trip-device actuated in step with the continueusly-running driving member aforesaid to free the detent from engagement with the rack-stop after; the plunger has been in theraised position fo a P dete mined interval. 7 a V v 8. In molding apparatus of the type specified the combination with a. pressureplunger of an elevator mechanism for the plun-' ger, a continuously-runningdriving member, a clutch movable to couple the elevator;

mechanism with said driving member, means actuated in stepqwiththe continuously-runmng member aforesaid periodically to throw in the clutch, resiliently-con trolled detent movable a,utoiiiatically into engagement with the plunger when the lat:

ter is raised and operativeto support said plunger in the raised position, means interconnecting the detent with the clutch and operative on movement of the detent into engagement with the plunger to throw out the clutch, and means actuated instep with the 101113111110IISlYflHDHlIlg member to disen-.

gage the detent after the plunger has been in the raised position for a predetermined interval.

, 9. In molding apparatus of the type speci- 'fied the combination withapressure-plunger of. an elevator mechanisnifpr saidi plunger, a continuouslyrunmhg drivnwfmember, a

clutch movable to couple the elevator mechanism with said di'iving inember, a resilient ly-coiitrolled 'detent 'aiitoiiiatically operative to engage the plunger whenthe latteris aised and to sup iortit in the raised position, .a tripdevice movable to release the detent from engag'ei'ncnt with the plunger, a

camshaft driven from the: continuouslyrunning member aforesaid, two levers one operativeiy connected w th the detent trip device and theother :Wlllll the :clutch aforesaid and both fulcrun'ied for movementabout axes parallelgwi-ththat of the cam' shaft, and two;caiiiscarried] on said cam shaft, one co-operating with the detent-control lever and the other withithe clutch-co r trol lever, said cams being sospaced apart ,angularly as to operate on their respective levers in such sequence and at such intervals as to provide a dwellof thepressure-plun ger in both upper and lower positions.

In testimony whereof I affix my signature:

JOHN STANLEY riaaeisonf 5

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