Mortar dispenser

The mortar dispenser disclosed herein utilizes a rotating auger extending through a feed barrel at the bottom of a supply hopper to force mortar through a nozzle attached to the barrel for use in tuck pointing. Formation of a rotating plug which would obstruct flow is prevented by an auger construction in which a single helical flute divides into a pair of flutes which, in the nozzle region, extend in opposite directions from the auger axis to provide two channels. The pair of flutes are apertured to permit mortar flow between the two channels and a slender elongate spring scraper prevents mortar from sticking to the nozzle. An agitator extending into the hopper is driven by a cam rotating with the auger so as to work mortar in the hopper and cause it to flow into the auger.

BACKGROUND OF THE INVENTION 
The present invention relates to a portable mortar dispenser and more 
particularly to such a dispenser which provides an even and continuous 
flow of mortar under pressure suitable for the tuck pointing of masonry. 
It has previously been proposed to employ gun-type dispenser for feeding 
mortar through a nozzle as an aid in tuck pointing. Such a gun-type 
dispenser is, for example, proposed in U.S. Pat. No. 2,908,425 issued to 
J. F. Denson. Somewhat similar constructions are shown in U.S. patents 
2,694,509 and 3,750,905. Such prior proposals, however, have not found any 
wide acceptance and this failure is believed to be due to difficulties in 
causing mortar to feed smoothly and particularly its tendency to form a 
rotating plug which blocks flow through the nozzle. 
Among the several objects of the present invention may be noted the 
provision of a mortar dispenser which will provide a smooth and even flow 
of mortar suitable for tuck pointing; the provision of such a dispenser 
which avoids clogging or jamming; the provision of such a dispenser which 
is easily used; the provision of such a dispenser which is easily cleaned; 
the provision of such a dispenser which is highly reliable and which is of 
relatively simple and inexpensive construction. Other objects and features 
will be in part apparent and in part pointed out hereinafter. 
SUMMARY OF THE INVENTION 
The portable mortar dispenser of the present invention employs a generally 
vertical hopper for holding mortar to be dispensed. A tubular feed barrel 
extends from the bottom of the hopper and a nozzle is releasably mounted 
at the end of the barrel. A feed auger extends along the bottom of the 
hopper, through the barrel and into the nozzle. The portion of the auger 
within the hopper utilizes a single helical flute extending radially from 
the auger axis but, toward the nozzle, the single flute divides into a 
pair of helical flutes which extend in opposite directions from the auger 
axis. Preferably, the pair of flutes are perforate in the region of the 
nozzle and the auger further includes a narrow elongate spring scraper 
which keeps mortar from sticking to the nozzle. In accordance with another 
aspect of the invention, an agitator is provided for working mortar in the 
hopper thereby to cause mortar to flow smoothly into the auger.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to FIG. 1, the mortar dispensing apparatus illustrated there 
is constructed in three general sections, a hopper and feed barrel body 
11, a nozzle 13 and an adapter collar 15 which allows the dispenser to 
utilize a conventional electric hand drill as a motive source, the 
electric hand drill being indicated generally by reference character 17. 
Except for various internal elements described hereinafter, the main 
structures of the body 11, the nozzle 13 and the adapter 15 may be molded 
from a suitable plastic resin, e.g. lexan or fiberglas reinforced epoxy. 
As may be seen in FIGS. 1 and 2, a housing body 11 provides a mortar 
holding hopper 21 which is generally vertically oriented but which has a 
slight rearward inclination in the particular embodiment shown. 
Preferably, the hopper is provided with a hinged cover 23 for retaining 
mortar in the hopper when the dispenser is set down. The hopper housing 11 
is provided with a rearwardly extending tang 37 which fits within a 
channel on the top of the adapter 15. The adapter 15 carries a stud 41 so 
that the hopper housing can be secured to the adapter by means of a wing 
nut 43. 
Extending horizontally forward from the bottom of the hopper is a generally 
cylindrical feed cylinder 25, the channel of the cylinder being continued 
along the bottom of the hopper as indicated by reference character 27. The 
nozzle 13 fits over the distal end of the barrel 25 and is sealed thereto 
by a pair of O-rings 31 and 33. The nozzle is releasably retained on the 
end of the barrel by a key or pin 35 which lies just behind the rim 
holding the rearmost O-ring 33 so that the nozzle can rotate. Thus, the 
tip of the nozzle can optionally be provided with transversely elongate or 
slot-like exit aperture and the exit aperture can be oriented either 
vertically or horizontally as desired. 
An auger, designated generally by reference character 45, extends across 
the bottom of the hopper 21 through the barrel 25 and into the nozzle 13. 
The right hand end of the auger includes a shaft 47 which extends through 
an opening in the rear of the body 11. A coupling 51 is provided for 
connecting the shaft 47 to the output shaft of the electric hand drill 17. 
Coupling 51 carries a cam 53 which is multi-lobed as may be seen in FIG. 
5. 
An agitator bar or rod 55 extends through a soft rubber bushing 57 fitting 
into a hole in the housing 11 slightly above the auger shaft 47 so that 
the rod is freely pivotable for small displacements. The exterior portion 
of the rod 55 carries a spool-like cam follower 59 which cooperates with 
the cam 53 to oscillate the agitator rod when the auger 45 is rotating. 
The corresponding oscillation of the inner end of the rod 55 works mortar 
in the hopper 21 causing it to flow relatively freely into the channel of 
the portion of the auger at the bottom of the hopper. The housing provides 
a rubbing block or post 58 which limits sideways motion of the rod. 
Preferred types of mortar are types N and O as designated in the Uniform 
Building Code, augmented by a pumping aid such as that sold under the 
tradename Darex by W. R. Grace and Co. of 62 Whittemore Avenue, Cambridge, 
Massachusetts. 
As indicated previously, the portion of the auger at the bottom of the 
hopper 21 comprises but a single helical flute extending radially from the 
axis of the auger. This flute is designated by reference character 61. 
Thus in the region of the hopper, the auger provides but a single channel 
for mortar being advanced by rotation of the auger. Adjacent the nozzle 
13, however, the single flute divides into a pair of flutes so that there 
are, in effect, two channels defined. The region of this dividing is 
designated generally by reference character 63. After a short distance, 
during which the two flutes progressively separate, they in effect extend 
in opposite directions from the axis of the auger. 
Once they are opposite to each other, the two flutes may, in one sense, be 
seen as opposite edges of a single twisted ribbon. However, since the 
flutes extend in both directions from the axis of the auger, it will be 
understood that there are in fact two channels defined by the auger in 
this region, i.e. within the nozzle section of the mortar path. As may 
also be seen, one of the channels is essentially blind or closed off at 
its right hand end, as viewed in the drawings, and thus is not initially 
filled with mortar. 
The twisted ribbon defining the pair of flutes is provided with a plurality 
of apertures, i.e. as indicated by reference characters 71. As pressure 
builds up in the initially open channel during the passage of mortar 
through the converging throat of the nozzle 13, this pressure is to some 
extent relieved by extruding of the mortar through the aperatures 71. This 
action, together with the dividing of the flute, is believed to inhibit 
the formation of a rotating solid plug which obstructs flow of the mortar 
out through the nozzle. 
Formation of a rotating plug in the nozzle is further inhibited by a thin 
elongate spring scraper, designated generally by reference character 75. 
As may be seen in FIGS. 3 and 4, the right hand end of the spring scraper 
75 extends through one of the apertures 71, lies in one of the channels 
for a short distance and then bows outwardly essentially into contact with 
the inner surface of the nozzle 13 close to the exit port. This spring 
scraper inhibits sticking of mortar to the nozzle. As will be understood, 
the spring scraper 75 is subject to wear due to the abrasive nature of the 
mortar but is relatively easily replaced since, with the nozzle removed, 
the scraper can be withdrawn axially by merely overcoming a small spring 
force. 
In view of the foregoing it may be seen that several objects of the present 
invention are achieved and other advantageous results have been attained. 
As various changes could be made in the above constructions without 
departing from the scope of the invention, it should be understood 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.