Apparatus for cleaning trowel blades

An apparatus for removing adhesive or other contaminants from a hand trowel. Two embodiments are disclosed, each including a body having a slot extending through at least a portion thereof, and through which the trowel blade is drawn for cleaning. A pair of opposing scraping blades is mounted to the body, on either side of an entry end of the slot. The blades are maintained in spaced relation, a distance approximating the thickness of the trowel blade. In one embodiment, the body includes, at one end, a handle for gripping. The underside of the body may also be attached to another blade, having a special scraping edge on its forward portion. In this configuration, the first embodiment performs yet another cleaning function, as a floor scraping tool. In the other embodiment, the body is structurally integrated with a reservoir, or trough, adapted for mounting over a portion of the lip of a bucket containing adhesive. The other embodiment also includes a separate scraping knife, for cleaning the planar underside of the trowel. The trough contains and confines the scraped-off adhesive, to prevent fouling of the fresh adhesive in the bucket.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention pertains to tools and methods used to install floor covering, 
such as adhesive-applied vinyl flooring. More specifically, the invention 
relates to devices which facilitate on-the-job cleaning of hand trowels, 
used by installers to spread and apply adhesive to floors. The invention 
herein is utilized continuously during the adhesive application job, to 
remove partially dried, hardened, and contaminated adhesive from the 
trowel. Contamination of the fresh adhesive is thereby minimized, and the 
quality of adhesion between the floor and the covering is enhanced. 
2. Description Of The Prior Art 
Vinyl flooring is installed by first spreading a fast-drying adhesive over 
an underlying floor surface, using a hand trowel. The trowel blade 
includes a plurality of small teeth, defining notches therebetween, along 
its edges. These notches are sized and configured to distribute the 
adhesive evenly, in a predetermined amount and pattern, as the trowel is 
drawn across the floor. Next, the vinyl flooring material is laid smoothly 
and progressively over the adhesive and compressed against the floor, 
removing air bubbles and forming a tight, adhesive bond therewith. 
Contamination of the fast-drying adhesive has long been a problem 
associated with the installation of such vinyl flooring. During 
application of the adhesive, the teeth of the trowel scrape across the 
floor, dislodging and picking up debris from the floor surface. This 
debris may include small pieces of material from a wood subfloor, a 
concrete slab, filler, or remains of "old" floor covering. Some of the 
debris becomes lodged in the notches between the trowel teeth, adversely 
affecting the amount and the pattern of the applied adhesive. The clogged 
trowel notches do not freely pass the adhesive, so that manufacturer's 
specifications for the proper amount of adhesive are not met. Other 
articles of debris become entrained in the adhesive actually applied to 
the floor, reducing its bonding efficacy. 
Contamination of adhesive is further spread by inadvertently mixing 
partially dried, or "set up" adhesive containing the debris, with fresh 
adhesive. Before scooping a new portion of adhesive for application, floor 
installers often clean their trowels by scraping the trowel blade on the 
lip of the adhesive bucket. The contaminated, partially dried adhesive 
either falls or eventually runs down the inner sidewall of the bucket, 
intermixing with the fresh adhesive material. This begins a chemical 
process which causes the new adhesive to deteriorate prematurely, and lose 
its full adhesive strength. 
The reduced amount and contaminated nature of the adhesive result in many 
undesirable defects in the new vinyl floor covering installation. These 
defects include: raised bubbles, opened seams, curled edges, weakened 
coverings detaching from a wall, and discoloration of the vinyl material. 
The need exists, then, for a device providing effective cleaning of trowel 
blades used for applying adhesive materials to floors. The need also 
exists for a device which can be used both for scraping and dislodging 
floor debris, and for cleaning trowel blades. The need further exists for 
a device which may conveniently be attached to the lip of an adhesive 
bucket, and includes both trowel cleaning structures and a reservoir, or 
well, to collect and store old or contaminated adhesive which has been 
removed from a trowel. 
SUMMARY OF THE INVENTION 
The invention disclosed herein is a trowel cleaning tool, used by floor 
installers to remove partially dried and contaminated adhesive from their 
trowels. One embodiment of the trowel cleaning tool assumes a handtool 
configuration, held by the installer in one hand while the other hand is 
used to apply the adhesive with the trowel. In this manner, the handtool 
is conveniently available for the installer, to be used concurrently as 
the adhesive is being applied. 
The handtool includes a body having a narrow, elongated slot, sized and 
configured to accommodate a lateral edge portion of the trowel blade. 
Opposing, parallel cleaning blades are included within the slot, arranged 
in spaced relation a distance slightly greater than the thickness of the 
blade. A grip or handle extends from the tool body, allowing the installer 
to grasp the tool firmly during the trowel cleaning process. 
When the trowel used for applying adhesive becomes fouled with old adhesive 
and debris, the rearward, lateral edge portion of the blade is inserted 
into the slot of the handtool. Holding the handtool firmly, the installer 
then draws the trowel toward him, until the entire extent of the trowel 
blade's lateral edge has passed through the slot. The cleaning blades 
scrape upper and lower faces of the trowel, and the bottom of the slot 
scrapes the notches clean. Any debris or old adhesive on the blade edge 
and within the notches is thereby removed. The spacing between the 
cleaning blades is adjustable, to accommodate different thicknesses of 
trowel blades and to compensate, over time, for wear. The blades are also 
removable, for cleaning and replacement as required. 
A bottom portion of the handtool body may be mounted to a trowel blade, 
providing additional advantages and features. A conventional trowel blade, 
having a replaceable or interchangeable handle feature, typically includes 
a detachable mounting system for the trowel handle. The present invention 
may be adapted to that detachable mounting system, allowing a conventional 
trowel to be retrofitted with the cleaning feature of the handtool. 
It is not uncommon for the installer to encounter small pieces of debris or 
loose filler material remaining on the floor, even as the adhesive is 
being applied. To deal effectively with that problem, the present 
invention may also be mounted to a trowel blade of special design. The 
special blade has a sharp knife on its forward end, allowing the handtool 
and blade combination to be used as a scraper to clean debris from floor 
areas. The forward, lateral portions of the special blade may also be 
provided with recesses, allowing the scraper knife to enter and clean 
otherwise inaccessible areas. 
A second embodiment of the invention assumes the configuration of a trowel 
cleaning accessory, having a base adapted for mounting over the rim of a 
bucket containing the flooring adhesive. The base includes a body portion 
having an elongated slot similar to that used in the cleaning tool of the 
first embodiment. A separate, horizontally oriented and upwardly facing 
blade is provided on the base, to allow the installer to scrape the lower 
face of the blade. The base also includes a reservoir, or well area, 
positioned beneath the entry end of the slot and underneath the scraper 
blade, to intercept and store, any old adhesive and debris removed from 
the blade. In this manner, the trowel may be cleaned without contaminating 
the fresh adhesive remaining in the bucket.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Turning now to FIG. 1, the first embodiment of the invention, a trowel 
cleaning handtool 11, includes a body 12 and a handle 13. The body may be 
constructed from aluminum, or another lightweight material of suitable 
strength. The configuration of the body is not critical, although the 
sloped sidewalls and the flat bottom portion shown in FIG. 1 do have some 
advantages, as will be discussed herein. Preferably, the handle 13 
includes a rubber or dense foam outer coating, to provide a resilient 
gripping surface. 
A slot 14 extends through a portion of body 12, and includes a blade entry 
side 16 and a blade exit side 17. The slot 14 is oriented and configured 
in a manner to facilitate the trowel cleaning operation using a hand-held 
tool. It should be noted that the plane of the slot is vertically and 
outwardly offset, in a direction away from the handle 13. This orientation 
allows the installer using the handtool, to grasp the handle and perform 
the cleaning operation more effectively than a vertical orientation for 
the slot would. 
In addition, the bottom of the slot 14 has a longer travel path than the 
top of the slot. Put another way, the outer edges of the slot, both at the 
entry side 16 and at the exit side 17, are upwardly and inwardly 
converging. This edge orientation is also reflected in the generally 
wedge-shaped the configuration of body 12. As will be discussed more fully 
herein, placing the plane of blade entry side 16 at a slant, or oblique 
orientation with respect to the bottom of the slot, reduces the effort 
required to draw the trowel to be cleaned through the handtool 11. 
The handtool as disclosed herein preferably includes a pair of cleaning 
blades 18 and a pair of blade holders 19, both at the entry side 16 and at 
the exit side 17 of the slot. When constructed in this manner, the 
handtool may be used both by right-handed and left-handed installers, with 
equal ease. The height of the cleaning blades 18 is generally coextensive 
with the depth of slot 14. Holder screws 21 are provided to secure blades 
18 and holders 19 within a recess 22 in the sidewall of body 12. In that 
manner, the outer surfaces of holders 19 are flush with the sidewall of 
body 12. 
U-shaped cutouts 23 are included in the cleaning blades, allowing lateral 
adjustment of each blade with respect to an opposing blade, and with 
respect to the slot 14. The cleaning blades are arranged in parallel, 
spaced relation, on either side of the slot. The distance between adjacent 
edges 24 of the cleaning blades is such that a blade 26 of a trowel 27, 
can pass edgewise, snugly therethrough. 
Trowel blade 26 typically includes a plurality of teeth 25 and notches 28 
around its outer edge, or periphery. The notches are designed to allow the 
passage of adhesive material 29 therethrough, as the installer scrapes the 
lateral edge of the trowel over the subfloor. As a consequence, adhesive 
is applied to the subfloor in the prescribed amount and in the proper 
pattern, to ensure a strong bond between the subfloor and the vinyl floor 
material. When these notches become clogged with flooring debris, or when 
the fast-setting adhesive becomes partially dried and hardened on the 
blade, the trowel blade should be cleaned. Effective cleaning of the blade 
reopens all of the notches and prevents old adhesive from contaminating 
both the flooring adhesive and the fresh adhesive remaining in the supply 
bucket. 
As shown in FIG. 4, a right-handed installer grips the handle 13 with his 
left hand, and holding the trowel 27 with his right hand, inserts the rear 
end of blade 26 into the entry side 16 of the slot 14. Then, the trowel 
blade is drawn entirely through the handtool 11, until the front end of 
the blade clears the exit side 17. During this process, the adhesive 29 on 
the upper and lower faces of the lateral edge of the trowel blade is 
scraped off by cleaning blades 18. At the same time, the notches 28 are 
scraped clear of debris, within the lower edge 31 of the slot. To protect 
the teeth 25 from undue abrasion and wear, a partially threaded bore 20 is 
provided in the body to accommodate a DELRON or plastic rod 30. A threaded 
plug 35 secures rod 30 within bore 20. Bore 20 extends from the rear 
exterior of the body slightly across the far side of slot 14, and is 
positioned so that its upper portion is slightly above the lower edge of 
the slot. Thus, the upper surface of the rod is similarly located within 
the median portion of the slot, to prevent metal to metal contact between 
the lower edge of the slot and the trowel teeth. In the event that the 
body is constructed from plastic or other another synthetic material, this 
sacrificial rod would not be necessary. 
A collection bucket, or other suitable container (not shown), is preferably 
placed beneath the handtool during the cleaning process, to catch the old 
adhesive and debris removed from the trowel. If necessary, this process 
may be repeated for the other lateral, or side edge of the trowel, and for 
the front end of the trowel as well. 
If the installer is left-handed, the cleaning operation is simply reversed. 
The handle 13 is grasped by the right hand of the installer, and holding 
the trowel with his left hand, the blade is inserted into the entry side 
of the slot 14. Then, the same cleaning operation as described above is 
undertaken. It should be noted that for a left-handed installer, the 
positions of the entry side 16 and the exit side 17 are reversed from 
those shown in the drawings. However, because the embodiment of the 
invention shown in the drawings includes two complete sets of blades, 
located on both entry and exit sides of the slot, it can be used both by 
right-handed and left-handed persons. In the event that the handtool is to 
be used only by a person having one hand preference or the other, only one 
set of cleaning blades on the selected entry side of the slot, is required 
for use of the handtool 11. 
Preferably, the body 12 includes a flat bottom portion 32, having an 
elongated, median groove 33 or receptacle extending from a forward end 34 
to a rearward end 36 of the body 12. Bottom portion 32 and groove 33 are 
configured to mate with corresponding structures on a handtool trowel 
blade 37. Trowel blade 37 may be of conventional design, as certain prior 
art trowel handles are detachable and modular, designed for use with a 
variety of replaceable blades. Various means of detachably coupling the 
blade and the handle are used, including tapered sliding structures and 
slotted openings for receiving buttons. 
Thus, despite the fact that the groove 33 shown in the drawings is 
elongated and generally rectangular in cross-section, it can be any 
desired size or configuration, depending upon the design of the prior art 
blade to which it attaches. In this manner, a prior art trowel blade may 
conveniently be modified or retrofitted with the handtool of the present 
invention. 
However, a handtool trowel blade 37 of special design is shown in FIGS. 5 
and 6. 
As will be discussed herein, this design provides several advantages over 
known prior art blades. For detachable coupling between the blade and the 
handtool 12, an elongated bar 38, generally rectangular in cross-section, 
is provided. Bar 38 is welded or riveted along the median axis of blade 
37, on its upper face 39. Groove 33 slidably engages bar 38, allowing 
adjustable placement of the handtool along blade 37. Three screws 41 
extend partially through body 12, from one side to the groove 33. Once a 
position for the handtool has been selected, the screws 41 are tightened 
to impinge on bar 38 and secure the handtool in place. 
Blade 37 also includes a replaceable knife 42 on its forward end, attached 
by means of plate 43 and screws 44. As shown in FIG. 5, the combination of 
the handtool 12 and the trowel blade 37 is used to scrape debris 46 from 
the subfloor 47. Although the subfloor is usually prepared for the floor 
covering operation by removing all debris and other foreign matter, 
sometimes the smaller particles are missed until the installer is on the 
floor and in the process of applying adhesive. In this situation, the 
separate trowel blade 37 fitted with the knife 42 is particularly handy. 
Also, areas of the floor which are relatively inaccessible using normal 
cleaning tools can be reached with the forwardly extending knife 42. For 
example, gypsum wallboard 48 is usually installed in spaced relation, 
usually 1/2" or so, from the subfloor 47. The area underneath the lower 
edge of wallboard 48 must be cleaned and free of all debris, so that 
adhesive applied to that area will form a tight bond with the vinyl 
flooring. Since it is difficult to access, this area poses unique problems 
for cleaning and clearing. The forward, lateral edges on either side of 
the blade 37 are provided with arcuate cutouts 49, to accommodate the 
lower, protruding edge 51 of wallboard 48. Thus, when the blade 37 is in a 
slightly raised position, as shown in FIG. 6, and the blade is being used 
either to scrape or clear the nearly hidden debris 46, the cutouts allow 
full entry of the knife 42 into the area. 
A second embodiment of the invention, a trowel cleaning accessory 52, is 
disclosed in FIGS. 7-10. Accessory 52 includes a base 53, or body, adapted 
for attachment to a portion of the rim 54, or lip, of a supply bucket 56 
containing fresh adhesive 57. Base 53 may be molded from plastic or other 
synthetic material, providing a simple and inexpensive method of 
manufacture. 
The periphery of base 53 includes an arcuate portion 58, extending partly 
around the rim of the bucket, and a lineal portion 59, connecting ends of 
the arcuate portion, and extending across the bucket. Beneath, and 
coextensive with the arcuate portion 58, is a semi-circular groove 61, 
sized and configured to accommodate a corresponding section of rim 54. In 
this manner, accessory 52 is temporarily attached to bucket 56, while 
adhesive is applied to the subfloor. 
The periphery of base 53 defines a reservoir 62, or well, sized and 
positioned to intercept and collect, old and contaminated adhesive 29, 
which is removed from a trowel 63. Trowel 63 is of conventional design, 
and includes the previously discussed teeth 25 and notches 28 along its 
lateral edges and its front edge. 
Also within the arcuate portion of the base periphery, are a slot 14 and a 
pair of cleaning blades 64 on the entry side 16 of the slot. Cleaning 
blades 64 are similar to cleaning blades 18 discussed previously. The 
principal differences are the lack of cutouts, for adjustment, and the 
shape of the upper and lower portions of the blades. Also, blade holders 
are not used to secure the blades in the accessory 52. Lastly, it should 
be noted that the planar orientation of slot 14 is vertical, and that only 
one pair of cleaning blades is used. These differences are not critical to 
successful practice of the invention, and reflect only obvious design 
choices in simplify and adapting the cleaning blades and the cleaning slot 
for use with the accessory 52. 
A V-shaped notch 66 is provided in lineal portion 59. The bottom edge of 
notch 66 is in co-planar alignment with slot 14. One purpose of notch 66 
is to provide an alignment guide when first inserting the trowel for 
cleaning. Yet another purpose for the notch is to accommodate the trowel 
blade during the cleaning process, allowing a more horizontal orientation 
of the lateral edge than would otherwise be possible. 
Accordingly, when it is time to remove contaminated or old adhesive 29 from 
the trowel 63, trowel blade 67 is lowered into the slot, with the rear end 
of the blade 67 in the entry side 16 of the slot. Gripping the accessory 
52 or the attached bucket 56 for stability, the installer draws the trowel 
blade 67 through the cleaning blades 64, as shown in FIG. 9. 
The cleaning blades 64 scrape the old adhesive 29 from either face of the 
blade, and the bottom portion of the slot 14 scrapes debris from the 
trowel notches 28. The debris and old adhesive fall into the reservoir 62, 
located beneath slot 14. In that manner, the debris and old adhesive are 
confined and prevented from contaminating the fresh adhesive 57. Since 
base 53 is preferably manufactured from plastic, a sacrificial rod 30 as 
described in the first embodiment, is not necessary within slot 14 to 
protect the teeth from undue wear. 
An elongated, horizontally oriented scraper blade 68 is also secured within 
base 53. This upwardly facing blade is provided as an alternative means of 
cleaning primarily the bottom face of trowel blade 67. The installer 
simply places the bottom face of the rear end of the trowel blade over the 
scraping blade, and draws the trowel away from the accessory 52 (see, FIG. 
10). As the adhesive 29 is removed from the trowel blade, it falls into 
the reservoir 62, where it is collected. In this manner, the trowel 67 may 
be cleaned in two different ways without contaminating the fresh adhesive 
57 remaining in the bucket. 
An alternative unitary cleaning blade 68 is shown in FIG. 11. Blade 68 
includes a web portion 69, connecting the two sides of the blade. A slit 
71 is provided in the blade, having opposing lateral edges, arranged in 
spaced, parallel relation. The width, or transverse dimension of the slit 
is such that the slit edges slidably engage the lateral edge of a trowel. 
Accordingly, the unitary cleaning blade 68 displays structural and 
functional equivalency with cleaning blades 18 and cleaning blades 64. 
Blade 68 may directly be substituted and used in lieu of blades 64; and, 
with slight modifications, blade 68 may also replace cleaning blades 18. 
Although it lacks the adjustment capabilities of cleaning blades 18, blade 
68 provides an inexpensive and simple alternative cleaning blade, for use 
with either embodiment of the present invention. 
It will be appreciated, then, that I have disclosed herein two embodiments 
of an apparatus for cleaning trowel blades, one comprising a handtool 
which may also be combined with a trowel blade to provide a subfloor 
cleaning capability, and the other comprising a convenient accessory for 
attachment to the lip of an adhesive bucket.