Roller having slip-on cage for paint roller cover

A cage for a paint roller is composed as a one piece, unitary construction having a plurality of projections. The projections make pressure contact with the inside of the bore in the center of the cover so as to prevent the cover from walking off the cage in use. The projections are formed to adapt to structural irregularities in the cover bore. A cage and cover sub-assembly and a paint roller incorporating the above is disclosed. The cage may have a tubular construction with the projections extending from the exterior of the tube, or the cage may have a beam-like construction along which hubs are spaced with the projections extending from the hubs and/or the beam.

This application relates to a novel roller cage for a paint roller and, 
further, to a paint roller which includes said novel roller cage. 
BACKGROUND OF THE INVENTION 
Paint rollers have come into very widespread use due to their ability to 
apply coatings, usually paint, economically and quickly. Nearly every 
paint roller in commercial use today consists of a frame which terminates 
at one end in a handle and, at the other end in a cage and cover support 
rod, a cage received on the support rod, and a roller cover received on 
the cage. The term "roller" or "roller assembly" when used herein will be 
used to refer to the just described components, namely (1) a frame having 
a handle and a support rod, (2) a cage and (3) a roller cover. 
The roller and the cage are almost always separable. This is so in order 
that the cover can be cleaned, or stored, possibly under water until the 
next use, or thrown away to make room for another cover. Thus the roller 
and the cage, at least, are assembleable and disassembleable components, 
and they form a sub-assembly of the roller assembly. 
The operating requirements of the assembleable/disassembleable cage and 
roller sub-assembly of the roller are well defined and, to some extent, at 
cross purposes. Thus the cage must securely hold the cover during use so 
that the cover does not "walk off" the cage during use with obviously 
disastrous consequences, particularly if the cover has just been fully 
loaded with paint. However, at the same time, the securement between the 
cover and the cage must not be so tight that separating the roller from 
the cage at the end of a session's use by the operator (i.e.: for 
cleaning, storage or discard) is difficult. In addition nearly all covers 
consist of an inner tube having a nominally constant bore, which receives 
the cage, and an outer surface to which the fabric receives and discharges 
paint. In many cases, due no doubt to the highly competitive nature of 
this product and thus the inability to provide highly-engineered 
components which always fit together perfectly, there is a degree of 
interference between the cover and the cage. The internal diameter of the 
bore may not be constant for example and thus the cage may have varying 
degrees of contact with the bore in those areas in which the inside 
diameter of the bore goes oversize. By the same token the outside diameter 
of the cage structure may vary due to manufacturing variances, or damage 
while in use, and hence sections of the cage may make no contact, or only 
imperfect contact, with the cover so that the convenient removal of the 
cover from the cage cannot be achieved. 
Further, many cages are structurally complex and hence both unduly 
expensive and unduly susceptible to improper functioning traceable to the 
complexity of the construction. Thus, for example, one widely sold roller 
includes a first cage element which is assembled to the free end of the 
support rod, the cage element including a plurality of radial fins which 
extend inwardly toward the center of the cover only a short distance from 
the free end, a second cage element which is assembled to the handle end 
of the cover and also includes a plurality of similar radial fins which 
extend inwardly from the handle only a short distance, and a third element 
consisting of a spacer which is located between the two opposed ends of 
the first and second elements, the only purpose of the spacer being to 
maintain the first and second elements in fixed, spaced relationship one 
to the other. The second element which is closest to the handle is often 
formed with a flange so as to preclude the cover from "walking" toward the 
handle. The first element cannot have such a flange of course or there 
would be no way to assemble the cover to the cage without running the risk 
of losing cage components, or improperly re-assembling the cage. Thus it 
will be noted that this common cage construction includes three quite 
separate and differently contoured components and substantial assembly 
costs are incurred in assembling them to the cover both in terms of 
equipment needed and time required. In addition, should the three cage 
components come lose from the cover after the sub-assembly of the cover 
and the cage have been removed from the support rod, the reassembly of the 
cage components to the roller may be beyond the mechanical skill of many 
consumers-users. Should the spacer be lost for example and the cover with 
the two end elements reassembled to the support rod without it, subsequent 
failure is likely to occur because there is nothing to maintain the end 
elements in proper spaced relationship. The outer core element may for 
example creep inwardly during use and paint will of course build up in the 
space at the end of the tube which has been vacated by the first cage 
element. Should the user carelessly or intentionally permit the deposited 
paint to harden prior to the next use, the removal of the cover, as when 
it is worn, or to install a different cover with a different fabric nap to 
do a different painting task, may be nearly impossible for the average 
consumer-user. 
A further shortcoming of most commercially available rollers is the high 
molding costs and the high assembly costs associated with fitting the cage 
and cover to the support rod using the current attachment methods such as 
crimps, washers, push nuts and other multi-piece attachment mechanisms. 
SUMMARY OF THE INVENTION 
The unique roller cage of this invention consists of a one-piece cage which 
can be quickly and simply snapped onto the cage and cover support rod of a 
roller handle whereby the cage is prevented from separating longitudinally 
from the handle, and onto which a cover may be easily assembled and easily 
disassembled, with the cover held tightly during use. Further, the cage is 
so constructed that it automatically adjusts to dimensional variations in 
the bore of the tube of the cover so that a gripping force exists between 
the cage and the tube at all locations without regard to dimensional 
variations which may exist in either or both of the cage and the tube. In 
addition, the cage is of one piece construction so that it can be 
economically molded and assembled to the support rod of the handle at a 
very low cost. 
The invention further consists of the combination of a handle and the 
roller cage as above described, the handle being constructed to receive 
the cage by a push-nut which, as mentioned, precludes longitudinal 
displacement of the cage and its associated cover from the handle during 
use, yet which permits easy disassembly of the cage and cover sub-assembly 
when a cover change is required. 
The foregoing is preferably achieved by forming the cage as a one-piece 
plastic or thermal plastic rubber member. A plurality of projections 
formed on the exterior of the cage are deformed by the tube as the cover 
is attached to the cage in a direction to exert a resisting force to the 
separation of the cover from the cage under normal working stresses. The 
projections may be either a plurality of rings or teeth arranged in a 
generally radial pattern, or the projections may be arranged in a 
generally longitudinally pattern with respect to the axis of the cage. In 
either event the projections are constructed to be deformed at their 
extremities whereby they come into contact with the tube of the cover so 
as to generate a frictional resisting force to the separation of the cover 
from the cage during use. In a first and second embodiment of the 
invention, the projections are formed as surface extensions of a tubular 
barrel, and in a third embodiment, the projections are formed as 
extensions of structural components of an open structure comprised of hubs 
joined by a longitudinal support beam.

DESCRIPTION OF THE EMBODIMENTS SHOWN IN THE DRAWINGS 
Like reference numerals will be used to refer to like or similar parts from 
Figure to Figure throughout the following descriptions of each of the 
embodiments of the invention shown in the drawings. 
Referring first to FIG. 1 a roller is indicated generally at 10. The roller 
consists in this instance of three main components, a handle, indicated 
generally at 11, a roller cage, indicated generally at 12 and a cover, 
indicated generally at 13. 
The handle 11 includes a hand grip 15, an extension section 16 which has an 
offset configuration, and a cage and roller support rod 17. The extremity 
of the support rod 17 is formed in a bullet shape 18 which terminates at 
its rear in a shoulder 19. A necked-down portion forms a collar ring 20, 
the collar ring 20 being of a smaller diameter than the diameter of the 
support rod 17 so that a shoulder is formed at 21. 
The cover 13 consists essentially of an inner tube 25 which is preferably 
formed from a suitable plastic such as polypropylene. Other flexible 
materials include polyethylene, nylon and thermal plastic rubber. The 
inside diameter of the tube is nominally constant from end to end of the 
tube but it will be understood that, in view of the materials and mass 
production methods used in manufacture, the inside diameter may vary 
slightly from location to location as will be amplified hereinafter. A 
cover is indicated at 26, the cover being secured to and surrounding tube 
25. In this instance a foam cover having a continuous, closed end 27 is 
shown. It will be appreciated however that a conventional pile fabric 
cover, which is open at the ends as indicated at 28 in the dotted line 
extension of the right end of the cover 26, may equally as well be used. 
The cage 12 is illustrated in assembled condition with a handle 11 and 
cover 13 to form a complete roller in FIG. 1. However, the features of the 
cage can be best appreciated from the showings in FIGS. 2-5 which are 
shown to a larger scale than FIG. 1. 
The cage 12 includes a barrel portion 30 which terminates at its right, or 
outer, end in an enlargement 31 and at its left, or inner, end in another 
enlargement 32. The left end of enlargement 32 terminates in a flange 33 
having an outwardly facing flange shoulder 34. It will be noted that the 
outside diameter of enlargement portions 31 and 32 are of equal diameter 
and of a size to be snugly received within tube 25. The flange 33 however 
extends outwardly beyond the outside diameter of tube 25 so that the left 
end of tube 25 butts against flange shoulder 34 in the assembled condition 
of FIG. 1. 
A constant diameter bore 36 extends from the chamfered end of the barrel 
to, in this instance, a location just within the enlargement 31. The 
diameter of the bore is sufficient to freely receive the support rod 17 
without binding, yet without appreciable looseness, so the cage and cover 
sub-assembly are able to rotate about the support 17 which is 
non-rotatable. The right end of the bore 36 opens into a necked down 
portion 37 of reduced diameter, the left end of necked down portion 37 
forming an abutment shoulder 38 which extends radially inwardly a distance 
sufficient to engage collar ring shoulder 21 of rod 17 should the cage and 
cover sub-assembly move to the left with respect to the support rod 17. 
The outer end of the necked down portion 37 opens into an end bore 39 
having a diameter larger than the diameter of the bore in necked down 
portion 37, thereby forming an annular shoulder 40. It will be understood 
that since the diameter of the base of the bullet nose 18 of rod 17 is 
larger than the diameter of the bore in necked down portion 37, rod 
shoulder 19 will butt against annular shoulder 40 when the cage and cover 
sub-assembly move to the right with respect to rod 17; see the FIG. 1 
position. 
A plurality of projections 42, 43 extend generally radially outwardly from 
the outside surface 44 of barrel 30. In this instance the projections are 
arranged in rows lying in vertical planes passing through the axis of the 
cage, and, further, there are 4 projections per row as indicated at 42a, 
42b, 43c and 42d in FIG. 4. As can be best seen in FIG. 4, the outer 
curved edges, one of which is seen at 42a, when in a relaxed, disassembled 
condition, project outwardly from barrel 30 a distance slightly greater 
than the outside surface of enlargement 32, as best seen in FIG. 4, and 
hence outwardly a radial distance slightly greater than the inside 
diameter radius of tube 25. 
When the cage is assembled to a cover as shown in FIGS. 1 and 5 the 
relationship between the projections 42, 43, the barrel 30, and tube 25 
are altered. Referring primarily to FIG. 5 it will be noted that when a 
projection, such as 42a, is located opposite a section of the tube 25 
which has a constant diameter, as at 29, the projection or fin 42a is bent 
to the left so that pressure is exerted between the projection 42a and the 
tube 25 which results in frictional resistance against movement in either 
direction of tube 25 with respect to projection 42a, but more so with 
respect to movement of tube 25 to the right with respect to barrel 30 and 
projection 42a. 
As mentioned, the bore of the tube 25, though intended to be of constant 
internal diameter, is not always constant from location to location due to 
various factors including manufacturing tolerances, etc. In the area 
indicated at 46 it will be seen that a slight outward bulge 47 appears in 
tube 25 resulting in an increase in the inside diameter of the tube 25 at 
that location, and the bulge is formed at the precise location where 
projection 43 makes contact with the inside surface 48 of tube 25. In this 
instance, the projection 43 still makes contact with surface 48 since the 
depth of the bulge does not extend outwardly beyond the relaxed extreme 
outer edge, represented at 42aa, of projection 43. The projection 43, 
while making contact with the tube 25, is under less deflection tension 
than projection 42a, and hence a lower frictional resistance exists 
between projection 43 and tube 25 than exists projection 42a and tube 25. 
Thus, even though the contour of the bore in tube 25 varies from location 
to location along its length, the projections on the barrel portion of the 
cage adapt themselves to such variations so that some pressure, and hence 
frictional resistance to longitudinal separation, exists at all contact 
points between the projections and the tube 25. 
It will be noted that in the solid line position of FIG. 1 a plug 49 is 
anchored in the outer end of tube 25 as by friction or sonic welding. In 
the dotted line position of FIG. 1 the closed end portion 27 of the cover 
has been eliminated. This construction will be particularly advantageous 
in connection with use of a conventional fabric cover which does not 
include a closed end. 
Referring now to FIGS. 6 through 9 it will be noted that cage 51 has 
longitudinal projections 52, 53, 54 instead of vertical or lateral 
projections 42, 43. 
Cage 51 includes a barrel portion 55 which terminates at its outer end in 
enlargement 31 and at its inner end in enlargement 32. From FIG. 9 it will 
he noted that each of longitudinal projections 52, 53 and 54 include a 
base portion 56 and a fin 57 extending outwardly from an associated base 
56. The fin 57 extends radially outwardly to a point which is located a 
greater radial distance from the axis 58 than the surface of enlargement 
31, and hence the inside surface of tube 25, all as best seen in FIG. 9. 
The fins 57 are sufficiently thin and flexible to be bent over as a tube 
25 is fitted over cage 51, the ends of the bent over or deflected portions 
57 of longitudinal projections 52, 53 and 54 thereby making pressure 
contact with the inside surface of the tube 25. As before, the pressure 
exerted between the fins 57 of longitudinal projections 52, 53, 54 and the 
tube 25 will create a substantial frictional resistance to relative 
movement between the cage and tube, and hence the tube and cover will not 
walk off the cage. It will also be noted that the fins or tips 57 of the 
projections 52-54 are sufficiently thin and flexible that contact will be 
made at all locations between the tube and fins, the fins 57 being 
deformed to a greater or lesser extent from location to location along the 
cage to accommodate variations in the contour of the inside of the tube. 
FIGS. 10 through 17 show a third embodiment of the cage of the present 
invention. This embodiment is believed to be particularly well-suited for 
application of the invention to larger rollers, such as those used to 
apply paint over large areas. 
FIGS. 10 through 13 show the longitudinal profile of a cage 112. A proximal 
hub 132 at one end of the cage 112 is joined to a distal hub 131 at the 
other end by a longitudinal support beam 130. (See also FIG. 15, which 
shows the beam 130 in cross-section.) The term proximal and distal are 
used to describe the hubs 132 and 131, respectively, because the proximal 
hub 132 is nearer to the supporting portion of a roller handle, and the 
distal hub 131 is farther from the supporting portion of a roller handle. 
The beam 130 acts to provide the cage 112 with structural integrity much 
in the way that the inner tube 25 of the embodiment of FIGS. 1 through 5 
and the barrel portions 55 is FIGS. 6 through 9 act as beams and possible 
structural support for the cage in the first and second embodiments. 
The beam 130 is comprised of two chord-like flat sections 133 and 134 which 
have longitudinal ribs 135 and 136, which add to the stiffness of the flat 
sections from which they extend. Four projections 137 extend radially 
outwardly from the rib 135, and four projections 138 extend diametrically 
opposingly from the rib 136. 
Spaced along the length of the cage 112 are four inner intermediate hubs, 
one proximal intermediate hub 142, one distal intermediate hub 144, and 
two inner intermediate hubs 140 and 147. The configuration of the 
intermediate hubs is best understood by a consideration of FIGS. 12 and 
16. Each of the intermediate hubs 140, 142, 144 and 147 has six 
projections 150, three extending in one direction and three others 
extending in an opposing direction. 
The inner intermediate hubs 140 and 147 are comprised of two axially offset 
half-hubs; the inner intermediate half-hub 140 is made up of two half-hubs 
146 and 148, each of which defines half of the aperture 153. The other 
inner intermediate half-hub 147 is comprised of two half-hubs 155 and 157 
which are axially offset and which define an aperture 152. Similarly, the 
proximal intermediate hub 142 has an aperture 154. The aperture 156 in the 
proximal hub 132 and the apertures 152, 153 and 154 are all concentric and 
are generally sized so as to receive a rod, and to allow rotation of the 
case 112 freely about the rod of the type shown in FIG. 1, while retaining 
the cage 112 on the rod. 
Retention of the cage 112 by a rod is accomplished by placement of a 
push-nut (not shown) on the end of a smooth rod, i.e. a rod which does not 
have a collar ring or the shoulders as shown in the rod of FIG. 1. Access 
to the smooth end of the rod, for purposes of installing a push-nut, is 
provided by the space between the two chord-like flat sections 133 and 134 
which make up the beam 130. 
The cage 112 is equipped with four rings of projections, each ring having 
eight projections. The pattern is best seen in FIGS. 15 and 16. Each ring 
of projections includes an upper projection 137, a lower projection 138, 
and six lateral projections 150. Each projection cooperates with the wall 
of a tubular roller in a manner as shown in FIG. 5, whereby the projection 
is deflected by the insertion of the cage 112 into a tubular roller. The 
flexibility of the projections is such that installation of the roller on 
a cage results in a tilting of the projection and a slight local 
deformation of the wall of the tubular roller. While the cage 112 has four 
rings of eight projections in each ring for a total of thirty-two 
projections, persons of skill in the art of plastic injection molding 
and/or roller design may vary the number of projections, the number of 
rings of projections, and the size and stiffness of the projections and 
the properties of the tubular roller to accomplish good retention 
performance without sacrificing resistance to "walk-off" and without 
sacrificing ease of removal of the roller for cleaning. 
FIG. 16 shows the configuration of the intermediate hub 147 and its 
half-hubs 155 and 157. The half-hub 155 is comprised of an inner portion 
which defines half of the semi-cylindrical aperture 152 and a web 158 from 
which extend the projections 150. It should be noted that the center one 
of the three projections 150, which are formed on the web 158, extends 
generally radially from the central axis of the cage 112, and the other 
two of those three projections 150 are generally parallel to the center 
one. This is to allow removal of the cage 112 from a two plate injection 
mold. 
FIG. 14 is a transverse section through a portion of the proximal hub 132. 
Spokes 162 extend radially from the sleeve 160 around the passageway 156. 
The spokes 162, together with the sleeve 160, connect the first inner 
flange 164 to the outer flange 166. 
The distal hub 131 also has a flange 165, similar in dimension to the 
flange 164. The flanges 164 and 165 are shaped to provide some sealing 
effect against the inside diameter of a tubular roller, so as to limit, or 
preferably prevent, the ingress of liquid into the inner portions of the 
cage 112 once the cage 112 is installed within a tubular roller. The 
larger diameter flange 166 acts as a stop against which an end of the 
tubular roller abuts when the roller is fully installed onto the cage 112. 
FIGS. 13 and 17 are end and sectional views, respectively, of the proximal 
hub 132 and show the configuration of the elements which make up the 
proximal hub 132. A recess 168 forms the flange 166 at the proximal end of 
the passageway 156. At the opposite end of the cage 112, the outer face of 
the flange 165 is preferably smooth. The distance from the inside edge of 
the flange 166 and the outer face of the flange 165 is preferably about 
the same as the length of a roller carried by the cage so that when a 
tubular roller is placed onto the cage 112, the distal end of the roller 
is flush with the outside face of the flange 165. 
It will be understood that embodiments shown herein are examples of the 
invention, and that numerous variations and modifications of the invention 
may be made without departing from the spirit and scope of the invention. 
Accordingly, the scope of the invention should not be judged by the 
foregoing descriptions but instead by the scope of the appended claims as 
interpreted in accordance with applicable law.