Pelletizer knife hub transport mechanism

Details Pelletizer knife hub transport mechanism Pelletizer knife hub transport mechanism

2003-02-20

2004-04-06

Davis, Robert (Department: 1722)

Plastic article or earthenware shaping or treating: apparatus

With apparatus assembly or dismantling means or with idle part

Blade type harvesting means or severing means

C425S311000, C425S313000, C294S081300, C294S081400, C294S067210, C294S067500

Reexamination Certificate

active

06716018

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to an apparatus for transporting a hub, including, for example, a mechanism for transporting a pelletizer knife hub.
2. Description of the Related Art
Many containers and other items are manufactured from plastics. Examples include motor oil containers, fruit juice containers, trash bags, tool covers, and many other items too numerous to list. These items are often manufactured through a molding, extrusion, or blowing process. The raw material typically used in the manufacturing process is provided in the form of pellets manufactured from a polymer, such as polyethylene.
Certain processes for manufacturing the pellets themselves involve the use of a pelletizer system. In many such systems, a melted plastic resin is forced through an extruder at high temperatures and pressures. The resin is forced through a die plate having up to 600 extrusion holes, with the resin being forced at pressures in excess of 600 psi. The extruded resin passes through the extrusion holes into an underwater chamber. The resin is then cut into small pieces by a series of knives which are rotated within the underwater chamber against the face of the die plate. As the resin is cut, it is cooled by circulated water, causing hardening of the material into numerous individual pellets. The pellets are then carried from the chamber downstream by the circulated water for drying and transport to customers.
FIG.
1
and
FIG. 2
depict a known knife hub which is rotated within a pelletizer system.
FIG. 1
presents a side view of a knife hub
50
as sold under the mark KOBE™. The knife hub
50
carries a plurality of knives
52
around its outer circumference. Each knife
52
has a blade surface
53
which rides closely along the die plate (not shown) in order to cut the resin. The blades are secured to the hub
50
by bolts
55
secured through the hub
50
. Typically, 16 to 24 knives
52
are radially disposed about the outer circumference of the hub
50
.
The hub
50
is rotated about a shaft
56
. The shaft
56
typically comprises an outer polygonal surface
54
which mates to a rotary motor shaft (not shown). The shaft
56
is more fully seen in the perspective view of the hub
50
in FIG.
2
.
The hub
50
also comprises a collar
58
. The collar
58
is offset from a body
57
of the hub
50
, leaving a gap between the collar
58
and the hub body
57
. The portion of shaft
56
residing within the gap is shown in
FIG. 2
at
56
′. Shaft
56
′ is generally circular in cross-section in order to receive a clamp (shown in
FIG. 3
) for aid in transporting.
It is periodically necessary to remove the knife hub
50
in order to inspect, repair, or replace the knives
52
. A pelletizer knife hub transport mechanism
10
is used to maneuver a pelletizer knife hub
50
into and out of service with a plastic resin pelletizer system.
FIG. 3
presents a perspective view of a known transport mechanism
10
as is used for transporting a pelletizer knife hub, such as hub
50
shown in FIG.
2
. The known transport mechanism
10
provides an elongated rail
15
. At one end of the rail
15
is a clamp
30
. The clamp
30
includes opposite clamping members
32
,
34
which are selectively opened and closed. T-bolt
38
aids in securing and releasing the opposite clamp members
32
,
34
in order to open and close the clamp
30
.
The clamp
30
is configured to engage the shaft
56
′ of the pelletizer knife hub
50
, such as the hub
50
shown in
FIGS. 1-2
. To aid in transport, a hoisting system is needed. To this end, the known transport mechanism
10
provides a hoisting connector
24
. The hoisting connector
24
defines a durable member fastened to the elongated rail
15
between the opposite ends. The hoisting connector
24
typically includes an eyelet
26
or other opening configured for receiving a hook
300
. The hook
300
is connected to a hoisting system (not shown) such as a bridge crane, an arm crane, or even a stationary block and tackle for providing a mechanical advantage in maneuvering the transport mechanism
10
. One or more cables
310
connect the hoisting hook
300
to the hoisting system.
To further aid in the transport of a pelletizer knife hub
50
, a counter-weight
20
is provided. The counter-weight
20
is normally positioned proximate to the hoisting connector
24
when the transport mechanism
10
is not carrying a hub
50
. However, the counter-weight
20
is slidable along the elongated rail
15
to the end opposite the clamp
30
when the clamp
30
engages the shaft
56
′ of the hub
50
. In this way, the transport mechanism
10
is balanced.
A counter-weight connector
22
is provided in order to connect the counter-weight
20
to the elongated rail
15
. The connector
22
is slidable along the elongated rail
15
in order to permit adjustment of the longitudinal position of the counter-weight
20
. However, known counter-weight connectors
22
do not swivel relative to the elongated rail
15
. Likewise, the hoisting system connector
24
does not swivel about the longitudinal rail
15
.
Disadvantages have been encountered with use of the known transport mechanisms
10
. First, it is necessary during the removal and maneuvering of a knife hub
50
to rotate the knife hub
50
from its operational vertical position to a horizontal position. In this respect, knife hubs are serviced and maintenanced while they are on a work stand in the horizontal position. This typically requires that the knife hub be placed manually onto the ground in the horizontal position for subsequent transport to a maintenance area. However, as noted, the known transport mechanisms
10
have no swiveling parts, making rotation of the knife hub
50
into a horizontal position difficult.
Those of ordinary skill in the art will further appreciate that the manipulation of a knife hub
50
is extremely difficult. In this respect, the knife hub typically weighs in excess of 100 pounds and cannot easily be manipulated by a single individual, even when supported by a transport mechanism
10
. Use of the currently known transport mechanisms
10
necessarily requires at least some manual manipulation of the hub
50
.
Other disadvantages have been encountered in connection with known transport mechanisms
10
. For example, once a hub
50
has been removed from a pelletizer system and lowered to the ground, the clamp
30
must be removed. A crew removing a hub
50
will place the hub
50
on the ground in a horizontal position, with the clamp
30
on top of the hub
50
. The hub
50
is then typically rotated manually 180 degrees in order to set the hub
50
within a transportation box or to perform maintenance on the hub. Additional manual manipulation is required during maintenance, including subsequent manual rotation of the hub
50
in order to reattach the hub to the clamp
30
after knives
52
are installed.
Examples of patents generally pertaining to apparatus that provide leverage for handling a device include U.S. Pat. Nos. 2,925,300; 4,759,674; and 5,088,610; French Patent Nos. 1,498,313; and 2,403,281. In particular U.S. Pat. Nos. 2,925, 300, 5,088,610; and FR 1,498,313 disclose a material handling device which is transported through an overhead conveyance system. However, a device including a clamp which will suitably engage a pelletizer knife hub in a sufficiently secure fashion to enable transport and manipulation of the hub is not suggested.
Thus, there is a need for an improved transport mechanism for a pelletizer knife hub. A need further exists for a pelletizer knife hub transport mechanism capable of rotating and otherwise manipulating a clamp while engaging the hub. Further, a need exists for a knife hub transport mechanism that swivels relative to the hoisting system.
SUMMARY OF THE INVENTION
Mechanisms and methods for transporting a hub are provided. For example, transport mechanisms for a pelletizer knife hub are disclosed. The mechanism first comprises a clamp for selectively engaging and

Affiliated with

Also associated with

Rating

Pelletizer knife hub transport mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Pelletizer knife hub transport mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pelletizer knife hub transport mechanism will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3250900