US3398901A

US3398901A - Destructor milling mechanism

Info

Publication number: US3398901A
Authority: US
Inventors: James E O'connor; Richard G Page
Original assignee: DOCUMENT DISINTEGRATION Inc
Current assignee: DOCUMENT DISINTEGRATION Inc
Priority date: 1966-02-14
Filing date: 1966-02-14
Publication date: 1968-08-27
Anticipated expiration: 1985-08-27

Description

Aug. 27, 1968 J. E. ocoNNoR ETAL 3,398,901

DESTRUCTOR MILLING MECHANISM Filed Feb. 14, 1966 5 Sheets-Sheet 1 as T Aug. 27, 196s J' E UCONNQR ETAL 3,398,901

DESTRUCTOR MILLING MECHANISM 5 Sheets-Sheet 2 Filed Feb. 14, 1966 Aug. 27, 1968 Filed Feb. 14, 1966 J. E. OCONNOR ETAL DESTRUCTOR MILLING MECHANISM 5 Sheets-Sheet 5 ug. 27, 1968 1 E O'CQNNQR ETAL DESTRUCTOR MILLING MECHAN I SM Filed Feb. 14, 1966 5 Sheets-Sheet 4.

Aug. 27, 1968 J. E. OCONNOR ETAL DESTRUCTOR MILLING MECHANI SM Filed Feb. 14, 1966 5 Sheng-sheet 5 ooo oooo ooooo /aoooo oooooo/ 7Z-4/oooooooo OOOOOOOO 76u44 A MAW @G5/ormai@ United States Patent O 3,398,901 DESTRUCTOR MILLING MECHANISM James E. OConnor, Los Angeles, and Richard G. Page,

Inglewood, Calif., assignors to Document Disintegration, Inc., Gardena, Calif., a corporation of California Filed Feb. 14, 1966, Ser. No. 527,137 7 Claims. (Cl. 2411-154) ABSTRACT F THE DISCLSURE An improved destructor mechanism is described in the following specification for reducing documents, paper and similar fibrous materials to a uffy illegible consistency. The mill to be described is -a two-stage type, and is constructed to operate satisfactorily for destroying all types of documents from heavy bound books, for example, to papers and the like.

The present invention relates generally to destructor mills, and it relates more particularly to an improved destr-uctor mechansim for destroying documents, paper, and the like, and for reducing the same to -a ufy illegible mass by mechanical means.

The disposition of discarded documents of a secret nature in such manner that the information contained therein cannot subsequently become available to rival manufacturers or enemy agents, has become a rather serious problem in modern times. Prior United States Letters Patents Numbers 3,189,286 and 3,192,853 relate to solutions of Iche problem.

However, the aspects of the problem to which the present invention is directed concerns the diiculty of adequately destroying such documents, particularly heavy or bulky documents such as bound books and papers which are apt to clog presently available destruction apparatus; as well as to the problem of positively reducing them to a uiy and entirely illegible mass Those problems have become particularly critical in these days of defense secrecy and industrial espionage.

In general, in accordance with the present invention, such destruction is accomplished by employing an apparatus including a housing providing a pair of interconnecting juxtaposed chambers. In each of said chambers a power-driven rotor carrying rigidly mounted documentdestroying hammers is rotatably mounted, and the rotors -are so relatively disposed that the hammers of the respective rotors cooperate to produce an explosive effect upon the documents which substantially contributes to the desired end result of the destructive operation.

A principal object of the present invention is to provide a dual-type of mill for reducing documents to an illegible ulfy consistency, which involves primary and secondary sections, constructed so that the primary and secondary sections operate as a single component yand cannot operate effectively independently of one another.

That is, each of the sections of the dual mill of the present invention complements the other and neither could fbe operated stisfactorily as a separate, single unit. In the embodiment to be described, both the primary and secondary sections have the same power. However, the rotor in the secondary section is driven at a faster speed than the rotor in the primary section. This is because the material increases in volume as it is pulverized, and the faster secondary section serves to lpull the material out of the primary section the less likelihood there is of a tendency for the primary section to become clogged. In this manner, the secondary section actually serves to increase the effective capacity of the primary section.

Patented Aug. 27, 1968 In the mill of the present invention the Crushers, or hammers, are rigidly mounted on their respective rotors in the primary and secondary sections rather than being pivotally mounted thereon, `as is usually the case in the prior art machines. The primary hammers have a particular shape, as illustrated herein, so as to break up the documents in the primary section; and the secondary hammers have a different shape, as also illustrated herein, so as to drag the material around the secondary section until it is completely pulverized.

The machine of the present invention, in the embodiment to be described, also includes a plurality of breaker bars which extend into the primary section, for example, through the housing. The primary hammers drive the material fed into the primary section against the heads of the breaker bars so as to initiate the p-ulverizing action.

However, prior to the material being driven against the heads of the breaker bars by the primary hammers, the housing provides a chamber adjacent the inlet which serves as an open area in which the material is exposed to the action of the primary hammers without the corresponding action of the breaker bars.

The above-mentioned open area permits the primary hammersto pulverize the material at close range immediately upon the material entering the inlet of the mill, and before the material is actually forced against the breaker bars. This enables the material to be broken up to some extent 'before it reaches the heads of the breaker bars, so that the tendency for bulky or heavy material t0 jam the machine is minimized.

The primary hammers and the secondary hammers in the mechanism of the present invention cooperate with one another to create an explosive area for the material. This explosive area occurs in the region between the primary and secondary sections, where the tips of the two sets of hammers successively pass one another in closely adjacent relationship in their respective angular travels.

The material fed into the mill of the present invention is driven by the primary hammers from the primary section to the secondary section. The material is so driven through an opening between the two sections and along a path such that the material is directed directly at the oncoming material in the secondary section and against the oncoming tips of the secondary hammers, The particles of material in the secondary section and the tips of the secondary hammers meet the particles from the primary section in mid-air, with a relatively high force. The resulting double action creates the explosive area in which the particles of material are rapidly pulverized.

The action described in the preceding paragraph creates an explosive condition. That is, the explosive condition occurs when the particles of material are driven in one direction at high speed by the primary hammers, so as to meet in a head-on collision with the particles in the secondary section and with the tips of the secondary hammers, which in that particular region are coming from the opposite direction. This action, of course, creates a high speed destruction condition of the material, so that the material is rapidly reduced to the desired utfy state.

In a constructed embodiment of the invention, and as will be described, both the primary and secondary rotors are rotated in the same direction, so as to create the condition described in the preceding paragraph. In addition, the secondary section is displaced down from the primary section, so that the axes of rotation of the primary and secondary rotors are disposed in a plane which is inclined at an angle of the order of 30 with the horizontal. It has been found that such an angle tends to produce the U maximum explosive effect in the aforesaid explosion area.

An object of the present invention, accordingly, is to produce -a rugged and lrelatively simple mechanism which is capable of reducing documents, and the like, to a lluffy consistency, and of achieving this rapidly and with little tendency for the mechanism to jam, even when bulky and relatively heavy documents are fed into the mechanism.

Other objects and advantages of the invention will become apparent from a consideration of the following description, when the description is taken in conjunction with the accompanying drawings, in which:

FIGURE 1 i-s a side elevational view of one embodiment of the improved mil-ling mechanism of the present invention;

yFIGURE 2 is a sectional view of the mechanism taken stantially along the lines 3 3 of FIGURE 1;

FIGURE 3 is a plan view of the mechanism taken substantially along the lines 3 3 of FIGURE 1;

FIGURE 4 is Ian end elevational view, taken along the lines 4 4 of FIGURE l, and with certain hatches, :rotors and other components removed, so as to reveal other operating components of the mechanism;

FIGURE 5 is Aa sectional view of the' secondary section of the milling mechanism taken substantially along the line 5 5 of FIGURE 2;

FIGURE 6 is a perspective representation, of the primary rotor of the mechanism;

FIGURE 7 is a perspective representation of the secondary rotor of the mechanism; and

FIGURES 8 and 9 are developed views of the interior of the primary section of the milling mechanism respectively taken substantially along the lines 8 8 and 9 9 of FIGURE 2.

As illustrated in the drawings, the milling mechanism of the invention is supported, for example, on a concrete 'base 10 (FIGURE 5 and is anchored into the base by appropriate anchoring means 12.

The mechanism includes a primary mill section and a secondary mill section, designated 14 and 16 respectively in FIGURE 2. A primary rotor 18 (FIGURE 6*) is mounted on la drive shaft 20 in the primary section; whereas a secondary rotor 22 is mounted on a drive shaft 24 in the secondary section (FIGURE 7). The shaft 20, for example, is rotatably supported in a pair of pillow blocks 28 and 30 (FIGURE 1); whereas the shaft 24 is rotatably supported in a pair of pillow '

blocks

32 and 34. The pillow blocks are mounted on an appropriate frame 36, which, as noted above, is anchored on the concrete base 10.

The secondary section of the mill is disposed at a lower elevation, with -respect to the primary section, so that the

shafts

20 and 24 lie in a plane which is inclined to the horizontal. This inclination may 'be of the order of 30, for example. It has been found that satisfactory results may be achieved with such an inclination. Although the inclination is not too critical, it has been found that with a 30 inclination, the material is held in the primary section long enough so that it can be reduced to a desired broken up form before it is introduced to the secondary section, and the material so int-roduced enters the secondary section at the optimum angle for maximum explosive effect.

A motor 40 (FIGURE 1) drives the shaft 20 through a suitable flexible coupling 42, whereas a separate motor 44 drives the shaft 24 through a suitable flexible coupling 46. The motor 40 may, for example, be a 150 horsepower, 1200 r.p.m. motor, of the 440-volt, 3-phase, 60-cycle type. The motor 44, may also be a 150 `horsepower motor, likewise of the 440-volt, S-phase, 60-cycle type. However, the motor 44 is faster than the motor 40, operating at a speed, for example, of 1800 r.p.m. Although the motor 44- is shown smaller than the motor 40 in the drawings, for reasons of clarity, actually they are of the same size in the embodiment under consideration. The

motors

40 and 44 are "bolted onto thel frame 36, as best shown in FIG- URE 1.

The mill itself is made up of a pair of side plates and 52, which are lbolted t-o the frame 36. The

side plates

50 and 52 are mounted in an upright, spaced and parallel relationship. The actual primary and

secondary sections

14 and 16 of the mill are formed by arcuate shaped members which extend across from one of the side plates to the other, and which are bolted to the side plates.

The

side plates

50 and 52, and associated arcuate components define an inlet 54 through which the material is fed to the primary section of the mill. A hopper 56 may be supported at the inlet 54, and a conveyor belt 58 (FIG- URE 2), maybe used to transport the documents up from the floor level to the mouth of the hopper 56, so that the documents may be dropped into the hopper, and thence through the inlet 54 into the primary section 14.

An exhaust duct 58 is mounted adjacent an outlet 60 in the housing, and the outlet extends from below the secondary section 16. The pulverized material from the mill is drawn through the exhaust duct, and is subsequently disposed. Any suitable means may lbe used to draw the pulverized material through the exhaust duct, such as described in the aforesaid patents.

As shown in FIGURE 2, for example, the milling mechanism of the present invention is actually a dual mill, including the primary section 14 and secondary section 16. The secondary mill section 16 is displaced down from the primary mill section 14 as mentioned above, and each operates in conjunction with the other, as will be described. That is, neither of the mill sections is suitable for independent operations, and each complements the other, so as properly to perform the desired pulverizing action.

One of the aforesaid arcuate components which extends between the side plates 50- and 52 is a cover 60. The cover 60 is pivoted to the frame 36 on a shaft 62. A lifter eye 64 is provided at the other end of the cover. The cover is held in place by bolts, such as bolts 66 extending through a flange of the cover and through the side plate 52 (FIGURE 2), and similar bolts extending through the side plate 50. When the machine is to 'be opened, these bolts are removed, and the cover may be moved back by a block and tackle, or by other suitable lifting mechanism, which is coupled to the eye 64. When the cover is opened, the interior of the secondary section 16 is revealed.

An arcuate section 68 is bolted to the

side plates

50 and 52, and as shown in FIGURE 2, this section extends between the side plates adjacent the inlet 54. The inner surface of the section 68 is smooth, so as to define an open area with the primary r-otor 18. The material introduced through the inlet 54 is initially exposed to the action of the primary rotor, without any further fracturing action in this open area. In this manner, the primary rotor is able to break up the incoming material t0 some extent as -a preliminary measure, so as to minimize the tendency for 'bulky or heavy material to jam the mechanlsm.

A second arcuate section 70 is 'bolted to the

side plates

50 and 52 adjacent the section 68, and this latter section likewise extends from one of the side plates to the other. It will be appreciated that the sections 68 and 70, and other arcuate sections to be described, serve to define the primary section 14 and the secondary section 16 of the mechanism.

A plurality of short breaker bars 72 extend through the arcuate section 70, so that the heads of the bars are disposed inside the primary section 14. These bars are bolted in place, as shown, and are formed, for example, of case hardened steel, with additional hardening being provided for their heads. The breaker -bars 72 are disposed in a pattern, such as shown by the developed view of FIG- URE 8.

It will be appreciated that after the material fed into the primary section 14 has undergone a preliminary breaking up in the aforesaid open area defined by the arcuate Section 68, the material is then driven against the heads of the 'breaker bars 72 by the primary rotor 18, so as to initiate the pulverizing action of the mill.

A further arcuate section 76 extends between the side plates and 52, and is bolted to the side plates. A further group of breaker bars 78 extend through the arcuate section 76, and these latter breaker bars are held in place by appropriate nuts, as shown in FIGURE 2. The breaker bars 78 may be disposed in a pattern such as shown by the developed view of FIGURE 9.

A further arcuate section 80 is bolted to the

side plates

50 and 52 and this latter section extends between the side plates on the opposite side of the inlet 54. A top breaker bar 82 is welded, 0r otherwise afiixed, to the arcuate section 80, and this breaker bar extends between the

side plates

50 and 52 to define the upper edge of the opening between the primary section 14 and the secondary section 16.

Yet another arcuate section 84 is bolted to the

side plates

50 and 52, and extends between the side plates. A bottom breaker bar 86 is welded, or otherwise attached, to the arcuate section 84, and this latter breaker bar forms the lower edge of the opening between the primary and

secondary sections

14 and 16 of the mill. The breaker bars 82 and 86, likewise, may be formed of case hardened steel, or other hard material.

It will be appreciated that the arcuate sections described above cooperate to define the primary section 14 of the dual mill, and the

arcuate sections

80 and 84 additionally define a portion of the secondary section 16 of the mill. The cover 60 also helps to define the secondary section 16, and that section is completed by an arcuate grating 88 which extends between the

side plates

50 and 52 at the bottom of the section.

As best shown in FIGURE 6, the primary rotor includes a plurality of rigid strip-like hammer members 90 which are keyed to the shaft 20, by means for example, of a key 92 (FIGURE 2). The hammer elements 90 are formed, for example, of hardened steel, with additionally reinforced corners. These elements are spaced along the shaft 20, and rotate with the shaft.

The secondary hammers are indicated as 96, and are best shown in FIGURE 7. These latter hammers are keyed to the shaft 24 by means, for example, of a key 98 (FIGURE 2). The secondary hammers, likewise, are rigid, and may be formed of case hardened steel and have additionally hardened edges.

As mentioned above, the

rotors

18 and 22 are driven in the same direction. Therefore, as the hammers 90 move up in the right hand portion of the primary section 14, the hammers 96 move down in the left hand portion ofthe secondary section 16.

As the material to be destroyed is introduced through the inlet 54, the hammers 90 originally break it up into realtively small pieces in the open area defined by the arcuate section 68. The material is then driven down against the heads of the breaker bars 72 and 78, so that it may be further pulverized. Then the material is driven up towards the opening between the primary section 14 and the secondary section 16, and against the breaker bars 82 and 86 which define that opening, by the action of the primary rotor 18. An explosion area for the material occurs between breaker bars 82 and 86, and where the tips of the two sets of hammers 90 and 96- successively pass one another in the opposite directions.

That is, the material fed into the secondary section 16 by the primary hammers 90 is driven directly into the path of the oncoming tips of the secondary hammers 96. Therefore, the tips of the secondary hammers meet the particles of material in mid-air and contact the particles with a relatively high force. This action creates a high speed destruction condition of the material so that it is rapidly reduced to a desired fluffy state.

The secondary hammers 96 then carry the fluffy material down against the grating 818, and it is passed through the grating when it reaches a desired illegible fiufiy con- 6v sistency. A further grating 100 is provided, so that the material must be reduced to a particular consistency before it will be passed to the exhaust duct 58.

The material to be discharged from the mechanism collects in a chamber 102 under the secondary section 16, and which cham-ber communicates with the outlet 60. A hatch 104 may be provided, so as to permit inspection of the material in the chamber 102.

As shown in FIGURE 4, suitable hatches may be provided in the side plate 50 to provide access to the primary section 14 and secondary section 16, for example, for cleaning purpose.

It will be appreciated, of course, that although the mill of the invention is shown as a permanent installation, it could just as well be mobile, as was the case of the particular embodiments shown in the aforesaid patents.

What is claimed is:

1. A milling mechanism for reducing fibrous material, such as documents, paper and the like, into a fiufiy illegible consistency including: a housing having a first compartment constituting a primary section for the milling mechanism and a second compartment constituting a secondary section for the mechanism; a first rotor including a plurality of primary hammer elements mounted in said first compartment for rotation about a first horizontal axis; a second rotor including a plurality of secondary hammer elements mounted in said secondary compartment for rotation about a second horizontal axis displaced from said first axis and parallel thereto; said housing including first components defining an arcuate wall for said first compartment having a smooth inner surface surrounding said first rotor, and including further components defining an arcuate wall for said second cornpartment having a smooth inner surface and surrounding said second rotor, said first components further defining an inlet in the arcuate wall of said first compartment for receiving material into said first compartment, said first components and said further components further defining an opening between said first compartment and said second compartment, and said further components further defining an outlet in the arcuate wall of said second compartment; a plurality of breaker bar members extending through said arcuate wall of said first compartment, said breaker bar members having individual heads disposed inside said first compartment and cooperating with said primary hammer element to break up the material introduced into said first compartment through said inlet; drive means for rotatably driving said first rotor and said second rotor in the same direction such that material passed through said opening by the tips of said primary hammer elements meets oncoming particles of material in said second compartment and the oncoming tips of said secondary hammer elements, whereby said material is rapidly pulverized to a fluffy consistency in said second compartment; and an exhaust duet surrounding said outlet externally of said second comparltment for drawing the pulverized material through said out et.

2. The milling mechanism defined in claim 1 and which includes a first breaker bar disposed across the upper edge of the aforesaid opening between said first compartment and said second compartment, and a second breaker bar disposed across the lower edge of the aforesaid openmg.

3. The milling mechanism defined in claim 1 in which said second axis is displaced downwardly from said first axis so that said first and second axes are disposed in a plane defining an angle of the order of 30 with the horizontal.

4. The milling mechanism defined in claim 1 in which said drive means drives said second rotor at a rotational speed higher than said first rotor.

5. The milling mechanism defined in claim 1 in which said primary and secondary hammer elements are rigidly mounted on said first and second rotors and extend radially outwardlyfrom said rst and second axes respectively.

6. The milling mechanism defined in claim 1 in which said breaker bar members extending through said wall of said first compartment are displaced arcuately from said inlet so as to provide an open area for said primary hammer elements to eng-age the material introduced into said first compartment through said inlet prior to the engagement of said material by the heads of said breaker bar mem-bers.

7. The milling mechanism defined in claim 1 and which includes a grating having a predetermined hole dimension mounted over said outlet.

References Cited UNITED STATES PATENTS Sedberry 241-154 X Rosenfeld 241-154 X Nicholson 241-80 West 241-154 Allen et al 241-154 X Beiter 241-154 l0 WILLIAM W. DYER, JR., Primary Examiner.

F. T. YOST, Assistant Examiner.