Rotary broom core assemblage

The invention provides an improved rotary broom assemblage of the type wherein a plurality of bristles are mounted upon a tubular core element and rotated by a shaft passing through the core element. The invention provides two pairs of circular plates, mounted in spaced relationship on the shaft, with each pair of plates defining an outwardly opening V-shaped groove within which a split ring fastening element is mounted. The tubular core is provided with an annular outwardly projecting depression in its wall portions adjacent each end of the core which are respectively engageable by a split ring member when expanded by axial movement of one of each pair of circular plates toward the other by fastening bolts. Additionally, an axially extending depression in the tubular core element cooperates with key slots in the circular plate members to insure the positive rotation of the core element with the circular plate members, while axial displacement of the core element relative to the shaft is positively prevented by the cooperation of the expanded split ring with the annular depression in the core member.

BACKGROUND OF THE INVENTION 
A large number of rotary broom constructions have heretofore been disclosed 
and utilized. In my prior U.S. Pat. No. 3,900,913 there is described and 
claimed a core mounting assemblage for a rotary broom wherein the tubular 
brush mounting core element of the rotary broom is detachably secured to a 
drive shaft through the provision of two spaced pairs of circular plates, 
one of which is rigidly secured to the drive shaft and the other of which 
is axially movable relative to the drive shaft. The peripheral surfaces of 
such plates are chamfered to define an outwardly opening circumferential 
V-shaped groove within which a split ring is mounted. Drawing of the 
movable plate toward its cooperating fixed plate effects an outward 
displacement of the split ring into frictional wedging engagement with the 
interior surface of the core element, thus providing detachable securement 
of the core element on the drive shaft. 
In the commercial utilization of such prior art constructions, it has been 
observed that the tubular core tends to shift axially with respect to the 
drive shaft, since it is only frictionally retained against axial 
movements by the expanded split ring. Such axial displacement results in 
the edge of the core being damaged by rubbing against laterally adjacent 
portions of the machine mounting the rotary brush and hence requires that 
the machine be taken out of service and the core assembly realigned to 
restore the brush mounting core to its proper axial position. 
OBJECTS OF THE INVENTION 
It is, accordingly, an object of this invention to provide an improved 
rotary broom assemblage. 
A particular object of this invention is to achieve the mounting of the 
tubular core element of a roary broom upon a drive shaft through the 
cooperation of an expandable split ring with an annular depression formed 
in the walls of the tubular core. 
A further object of this invention to eliminate the keys that were 
previously welded to the interior surface of the tubular core by forming 
axial depressions in such surface which function as keys. 
Other objects and advantages of the invention will be apparent to those 
skilled in the art from the following detailed description, taken in 
conjunction with the annexed sheet of drawings.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to the drawings, the numeral 10 represents a brush mounting core 
for a rotary broom. As is well known to those skilled in the art, a 
plurality of bristles (not shown) are generally disposed in channel shaped 
spiral or circular elements mounted on the exterior surface of the core 
10. Since such bristles wear in use, it is desirable that the entire core 
element 10 be readily removable from its mounting in the machine, and 
particularly, readily removable from its drive shaft 1, which is normally 
co-axially disposed within the core 10. 
In accordance with this invention, the detachable securement of the tubular 
core 10 with the drive shaft 1 is effected by the utilization of two 
spaced pairs of circular plate elements 2. One element 2a of each pair is 
rigidly secured to the drive shaft in any conventional fashion, as for 
example, by welding. The other circular plate 2b of each pair is axially 
movable relative to the drive shaft 1 and, in particular, is movable to an 
abutting position with the fixed circular plate 2a as shown in FIG. 1 
through the tightening of fastening bolts 3. 
The abutting surfaces of each pair of plates 2 are provided with chamfers 
2c and 2d respectively to define an outwardly opening circumferential 
V-shaped groove 4. A split ring expansion element 5 is mounted in the 
groove 4 and the normal diameter of ring 5 is such that the periphery of 
the ring will lie at or below the periphery of the circular plates 2. This 
diameter is selected so as to permit the combined assemblage of circular 
plates and split ring to be readily insertable within the interior of the 
tubular core 10, with each pair of circular plates 2 respectively disposed 
adjacent the end portions of the core 10. 
In accordance with this invention, that portion of the tubular core 10 
which overlies the outwardly opening circumferential V-shaped groove 4 
defined by each pair of plates 2 is deformed outwardly to define an 
annular depression 10a into which the split ring 5 may be expanded by 
tightening of the fastening bolts 3. In this manner, the tubular core 10 
is rigidly locked to the plate assemblages 2, hence to the drive shaft 1, 
against any and all axial displacements. Additionally, the frictional 
engagement of the split ring 5 with the interior surface of the depression 
10a assists in the driving of the core 10 for corotation with shaft 1. 
To insure that the tubular core 10 is positively locked to shaft 1 for 
co-rotation, each of the plates 2 is provided with an axially extending 
key way slot 2e which are in axial alignment. An axially extending 
depression 10b is then formed in each end portion of the core 10 and these 
depressions extend into the key way slots 2e to lock the core 10 to the 
circular plates 2, and hence to the shaft 1, for co-rotation. The ends 5a 
of split ring 5 lie on either side of axial depression 10b. 
At any time that it is necessary to replace the core and bristle assembly, 
it is only necessary to loosen the fastening bolts 3, which permits the 
movable plate 2b to be shifted axially away from its abutting engagement 
with the fixed plate 2a and hence permits the split ring 5 to compress to 
its normal position wherein it lies entirely within the confines of the 
internal diameter of the tubular core 10. The ends of the split ring 5 
are, of course, disposed on opposite sides of the key slots 2e and hence 
provide no interference with the entry of the axial depression 10b into 
such key slots. 
Modifications of this invention will be apparent to those skilled in the 
art, and it is intended that the scope of the invention be determined 
solely by the appended claims.