US3051990A

US3051990A - Rubber reclaiming apparatus

Info

Publication number: US3051990A
Application number: US42036A
Authority: US
Inventors: Chester H Peterson
Original assignee: U S Rubber Reclaiming Co Inc
Current assignee: U S Rubber Reclaiming Co Inc
Priority date: 1960-07-11
Filing date: 1960-07-11
Publication date: 1962-09-04
Anticipated expiration: 1979-09-04
Also published as: GB902943A; NL264577A; DE1192400B; NL131618C; LU40225A1; FR1290471A; ES261306A1; BE603469A

Description

Sept. 4, 1962 Filed July 11, 1960 FIG.|

2 Sheets-Sheet 1 INVENTOR. 5455227 /.V/%reao v Sept. 4, 1962 c. H. PETERSON 3,051,990

RUBBER RECLAIMING APPARATUS Filed July 11, 1960 2 Sheets-Sheet 2 FIG.2

I N VEN TOR. 62-15752 1% /%/21JOM "WW/M4 MM 3,951,990 Patented Sept. 4, 1962 free 3,051,996 RUBBER RECLAIMHNG APPARATUS Chester H. Peterson, Eggertsvilie, N.Y., assignor to US. Rubber Reclaiming Co., Inc., Cheektowaga, N.Y., a corporation of New York Filed July 11, 1960, Ser. No. 42,036 8 Claims. (Cl. 1814) This invention relates to apparatus for the continuous reclaiming of rubber (i.e. vulcanized conjugated diene polymers, and the like), and more particularly to im provements in the means for conducting the reclaimed rubber away from the means whereby it is reclaimed while being propelled forwardly.

It has been found that an improved product is provided if successive refining actions between moving and stationary surfaces are carried out during the movement of the reclaim forwardly from the propulsive means. In addition, it has been found that a high uniformity of the product can be secured when such movement is conducted in a straight line from the propulsive means to the final extrusion orifice, so that the various portions of the reclaim will be subjected to similar conditions during its forward movement.

1 It is also of importance that the reclaim be subjected to a cooling action between successive refining steps.

With the foregoing and other considerations in view, the present invention contemplates the provision of forwardly disposed means secured to and rotating on the same axis as a reclaiming screw and of cooperating stationary means serving as a forward continuation of the reclaiming casing in which such a screw operates whereby there are provided successive annular restricted refining channels separated by a wider annular channel.

In various of' its more specific aspects, the invention contemplates the provision of cooling means at said wider annular channel, the provision of particularly shaped channels, the provision of means for readily adjusting the size of the final annular channel, the provision of means for conducting the reclaim beyond the orifice of the final channel, and other features of construction as will more particularly appear hereinafter.

By means of the present invention there is provided an additional degreeof working whereby a supplemental refining action is obtained and tendencies for unplasticized particles to leave the machine are minimized.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts, which will be exemplified in the constructions hereinafter set forth and the scope of the application of which will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a longitudinal section view of one form of apparatus embodying the invention;

FIG. 2 is a transverse sectional view along the lines 22 of FIG. 1; and

FIG. 3 is an exploded view showing certain of the parts.

In the illustrated embodiment of the invention, there is provided an elongated hollow cylindrical casing in which rubber, delivered in comminuted form to the rearward end thereof, as from a suitable hopper (not shown), may be reclaimed as it is worked and propelled forwardly therethru by a screw 12 which is rotated by a suitable source of power such as an electric motor (not shown). The screw 12, in the present instance, is formed with a series of sets of propelling thread portions 14 and working thread portions 15, projecting only slightly from a thick stem 16, as, for example, set forth in United States Patent 2,653,348. The screw in the present instance may be 12 inches in diameter.

From the forward end of the casing 10 and providing therewith a continuous interior wall 17 is a casing por tion 18 the diameter of which decreases gradually in a forward direction, and forwardly of this is a similar casing portion 28 providing a further continuing interior wall 21 which slopes inwardly more sharply, and a still further continuing wall 22 which slopes outwardly.

The forward end of the screw 12 is provided with a threaded bore 24 in which is tightly screwed to rotate with the screw 12 a rearward projection 25 from a cone 26 having an outer forwardly interior sloping wall 27 arranged to provide a restricted annular channel 28 between it and the wall 17, the walls 17 and 27 being substantially uniformly spaced throughout their longitudinal extent. At the rear end of the rotating cone 26 a wall 30 which slopes outwardly from the stem 16 is provided. Cooling passageways 31 are provided in the housing which surrounds the rotating cone 26.

Forwardly of the wall 27 is a cone portion 32 having an outer wall 33 which slopes inwardly more sharply than the wall 21. threaded bore 34 in which a threaded projection 35 on a mandrel 36 is tightly screwed. On the outer cylindrical surface 40 of the mandrel 36 there is tightly but slidably fitted a rotating inverted conical die 42, the rearward sliding movement of which is limited by cooperating

shoulders

43 and 44 on the mandrel and the die 42 respectively. The fit of the die 42 on the mandrel is tight enough to assure the rotation of the die with the mandrel. A key 45 and keyway 46 may be provided, if desired, so as to assure more positively the rotation of the die 42 with the mandrel 36 and the screw 12. The mandrel is provided with a threaded forward projection 48 on which there is screwed a nut 49 which may be screwed in fully (to the position shown) to hold the end piece in a rearward position shown or only partially to permit the pressure of the rubber thereon to hold the rotating die 42 more or less forwardly as desired.

The outer wall 52 of the rotating die 42 has a slope corresponding to the wall 22 and provides a channel 54' therebetween. When the

shoulders

43 and 44 are in contact, the channel 54 is much more restricted than thechannel 28, but the effective size of the channel 54 may be increased by the adjustment of the nut 49 when desired, tho ordinarily not so much as to reduce the resistance to flow or the back pressure in chamber to such a degree that voids would form or be capable of forming.

The wall 52 extends rearwardly of the wall 22, inside the wall 21, so that a wide channel or plenum chamber 60 is provided between the channels 28 and 54; and outside the casing portion 20 there is provided a chamber 62 thru which a cooling fluid may be flowed. The plenum chamber 60 serves to smooth out the flow of material and to absorb pressure surges. It serves further to provide a degree of cooling after the intensive shearing action on and consequent heat building up in the material.

Rubber worked, propelled, and reclaimed within the casing 10 flows thru the channel 28 where it is refined by the rotation of the cone 26 with respect to the stationary wall 27, thru the chamber 60 where it is, preferably, compacted and cooled, and out thru the channel 54 where it is further refined.

In order to remove the hot reclaimed rubber forwardly away from the channel 54 and beyond the casing portion 20, so as to avoid the possibility of hot rubber adhering to an irregular surface such as that of the nut 49, there is mounted on the forward end of the rotating die 42 a polished hollow cylindrical member 65 of the same outer diameter as the forward end of the die 42 and on This cone portion 32 is formed with a which the rubber slides easily without adhering, this member being held in place by an annular cross-piece 66 which is integral therewith and which fits between the nut 49, and a lock nut 67 which is screwed on the outer end of the mandrel 36. The nut 67 and the member 65 may be removed to permit the adjustment of the nut 49.

By the use of a construction such as exemplified, excellent control of flow is obtained thru more efficient cooling and simple adjustments of clearances. The result of the tandem operation of the rotating cone, plenum chamber, and rotating die is to provide a smooth, uniform flow at desirably low exit temperatures. External cooling without excessive smoking is certain and effective. Fume and smoke control are positive and effective. Points of hold-up, i.e. dead spots, in which material could cure up and present difliculties in the finishing operation, are eliminated. Maintenance and initial cost are low. Because of the steady flow and the rotation of the die, die wear is not critical since it is uniformly concentric around the circumference. This results in more uniform clearance adjustment as wear progresses. A high degree of production is obtained, shut-down and start-up times are short, and great simplicity of construction is attained.

Since certain changes may be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

The invention claimed is:

1. Rubber reclaiming apparatus comprising a stationary outer wall providing a cylindrical reclaiming chamber, a screw rotatable within said chamber for moving rubber forwardly thru said chamber to reclaim it, means providing an annular passageway beyond the discharge end of said screw and comprising stationary outer wall means and an interior wall means secured to said screw and rotating therewith and providing with said outer wall a rearward restricted annular channel and a forward restricted annular channel, and providing also between said rearward restricted channel and said forward restricted channel a wider annular chamber which is less restrictive than either of said channels and the interior wall of which rotates with said screw and the exterior wall of which is stationary, said forward restricted channel being more restrictive than said rearward restricted channel.

2. Apparatus as in claim 1 wherein cooling means is provided exteriorly of said wider annular chamber.

3. Apparatus as in claim 1 wherein said outer wall is of less interior diameter at said forward channel than at said rearward channel.

4. Apparatus as in claim 1 wherein said wall means decrease in diameter along said rearward annular channel and increase in diameter along said forward annular channel.

5. Apparatus as in claim 4 wherein the forward portion of said interior wall means is adjustably mounted to vary the size of said forward annular channel.

6. Apparatus as in claim 1 wherein there is provided, at the forward end of said interior wall means, means extending forwardly beyond said outer wall means to guide the reclaimed rubber beyond the forward end of the latter.

7. Apparatus as in claim 6 wherein said forwardlyextending means is removably mounted.

8. Rubber reclaiming apparatus comprising a stationary hollow cylindrical casing, rotatable screw means therein for reclaiming rubber and moving it forwardly the'rethru, a gradually-decreasing-diameter conical element mounted on the forward end of said screw means and rotating therewith, stationary wall means serving as a continuation of said casing and defining a restricted annular channel between it and said conical element, a reduced-diameter element extending forwardly from said conical element and rotating therewith, further exterior stationary wall means forming an annular chamber outside said rotating reduced-diameter element, a shaft threaded into said reduced-diameter element and rotating therewith, an increasing-diameter conical element fitted on said shaft for rotation therewith, and further stationary wall means defining a restricted annular channel about the last-mentioned conical element said annular chamber being less restrictive than the first-mentioned annular channel and the second-mentioned annular channel being more restrictive than the first-mentioned annular channel.

References Cited in the file of this patent UNITED STATES PATENTS 454,030 Clark June 16, 1891 1,159,895 Canda Nov. 9, 1915 2,461,630 Cozzo Feb. 15, 1949 2,514,841 Chase July 11, 1950 2,747,223 Cady May 29, 1956 2,979,768 Nichols Apr. 18, 196-1 FOREIGN PATENTS 961,211 Germany a Apr. 4, 1957