Perpetual calendar

An improved permanent calendar assembly is disclosed which is to display any month of any year. The construction includes a flat main body with forwardly protruding tracks for removable mating with date columns. For flexibility of display, end pieces carrying one of the dates "29", "30" and "31" on one surface and a blank on an opposed surface are rotatably or pivotally mounted at the bottom of the date columns so that either side of any of the end pieces may be selected for display. The calendar also features a construction that allows easy removal and rearrangement of the vertical date columns and yet prevents their disengagement when, for example, when the calender is tilted forward. At least one lipped horizontal track extends across the rear of the date column area. Defined in the back wall of each date column are at least two openings or grooves that can mate with the track, as desired. The lip results in a track with surfaces facing in more than one direction and particularly with an engaging surface which has a surface that mates with an opposed surface in each date column groove when the calendar is tipped forward to prevent the date column from falling.

This invention relates primarily to constructions for calendar displays 
and, more particularly, to constructions for displays adaptable to show 
the dates in any month of any year. 
Permanent calender displays are known in the art which comprise a series of 
columns attached to a substantially flat main body. A basic problem 
contended with in such calendars is providing a display which is 
conveniently adapted for months that are "28", "29", "30", and "31" days 
long. Most months it is necessary to re-position the vertical date 
columns, and to adjust certain of them to account for the length of the 
month. 
In U.S. Pat. No. 4,142,311, there are disclosed a number of arrangements 
for coping with the "month length" problem by providing endpieces at the 
bottom of selected date columns which are rotatably reversible to indicate 
various month lengths. These arrangements have provided a particularly 
effective solution to the "month length" problem. However, a construction 
was needed which would be more amenable to modern mass production 
techniques and particularly to being made from a plastic material by 
conventional processes. 
Accordingly, a primary object of the present invention is to provide an 
improved permanent calendar construction. 
Another object of the present invention is to provide a calendar structure 
which solves the month-length problem by permitting adjustment of the last 
date in selected date columns. 
Still another object of the present invention is to provide vertical date 
columns indicating variable length months which may easily be removed from 
and replaced on the main calendar body member. 
A further object of the present invention is to provide a permanent desk 
calendar which is simple in construction, yet attractive and convenient in 
use. 
Still a further object of the present invention is to provide a device of 
the character described which may be manufactured from various plastic 
materials by conventional processes and is highly durable in use. 
Still another object of the present invention is to provide a construction 
of the character described which is simple and inexpensive to manufacture, 
yet durable and simple to operate. 
These and other objects of the present invention are accomplished in 
preferred and alternative embodiments of the present invention which 
feature a generally flat main body member with forwardly protruding tracks 
upon which are positioned seven date columns. The "month-length" problem 
is dealt with by providing a rotatable or pivotally mounted, reversible 
portion at the bottom of at least one of the date columns. Preferably, the 
reversible portion is in the form of a block which has a numeral on one 
side and is blank on the opposite side. The block may then be positioned 
to display either its numeral or the blank. Preferably, the three columns 
including the numerals "29", "30" and "31" are provided with such 
rotatable portions so that the display can be adjusted to display any 
number of days, from 28 to 31, by appropriately manipulating the 
reversible portions.

Turning in detail to the drawings, and more particularly to FIG. 1, there 
is shown a permanent calendar 10 comprised broadly of a main body member 
12, vertical date columns 14, and a support stand 16. 
More specifically, the main body member 12 includes an upper portion 18 
containing a month receptacle 20, in order to retain a plurality of month 
display members 22. Each of the month display members displays indicia 22a 
of two months on each of its sides 23. The said two months are arranged in 
an upside-down relationship so that only one legible month at a time is 
displayed through display window of receptacle 20. These units may be 
rearranged in the well known fashion to display the appropriate month. The 
upper portion 18 also includes a weekday indicia 24 which permanently sets 
forth the columns for the particular day of the week for the month in 
question. 
Depending downwardly from the upper position 18 is a left side wall 26 and 
a right side wall 28 defining the date column area of well 30 all within 
the lower portion 32. The well is bounded in the rear by the man body 
front wall 34. 
Protruding into the date column area 30 are date column tracks 36 onto 
which are selectively and removable mounted date columns 26a, 26b, 26c, 
26d, 26e, 26f, 26g. Each date column displays four date indicia, each 
separated in numerical value from the preceding and succeeding displayed 
date on that date column by seven. Thge date columns each have two 
rearwardly open track openings 72, so that at least two positions of 
height of attachment are within the mating capability of each date column. 
Positioned on the front wall 34 and towards the upper portion 18 is the 
lipped track 36 as shown in the preferred embodiment. Alternatively, as 
shown in FIG. 19, the tracks may consist of two uni-directional tracks 36' 
with three mating open track openings 72'. The track consists of a 
horizontal portion also has a major horizontal axis 43 which is 
perpendicular to the major axis on the front wall. Extending upwardly from 
the horizontal portion 38 is a vertical portion 44 which is parallel to 
and spaced from the front wall and is perpendicular to the horizontal 
portion. The vertical portion is defined by an inner surface 46, an outer 
surface 48, and a top surface 50. The portion also has a vertical axis 51 
which is perpendicular to the horizontal axis 43 of the horizontal portion 
38. 
The main body member 12 is bounded on the reverse side by a rear wall 52 
having an opening 54 for a hainging hook. The rear wall also has defined 
therein a cut-out portion 56 for the purpose hereinafter appearing. 
The structure shown in FIGS. 1 and 2 for the date columns 14 and the 
securement means will be described as having a rotatable mounting 
structure 26'a" including an end piece 26"a" retained to the main column 
14 by means of a screw 62 and a compression spring 64. The particular 
embodiment shown includes a ridge 66 defined in the date column. Of 
course, any type of means may be utilized to retain either permanently or 
detachably, an end piece to the vertical date column. 
Defined in the rear wall 70 of each date column 14 are at least two track 
receiving openings or grooves 72. The openings are defined by a horizontal 
base surface 74, extending inwardly from the outer wall. Then, extending 
upwardly is a vertical surface 76 terminating at an upper horizontal 
surface 78 parallel to the horizontal surface 74. The surface extends 
outward towards the rear wall for a short distance and then there is 
depending therefrom a parallel opposed short vertical surface 80 and then 
another parallel opposed short horizontal upper surface 82. This surface 
is parallel to the surfaces 78, 74 and extends outwardly to the rear wall 
70. The surfaces 74, lower part of 76 and 82 form a slot 88 and the 
surfaces including the upper part of 76, 78, 80 form a channel 89. 
The width between the parallel vertical surfaces 76, 80 is defined as X and 
is identified by the numeral 84. In a similar manner, the distance between 
the parallel opposed vertical surface 80 and the rear wall 70 is defined 
by the width "Y" and identified by the reference numeral 86. Furthermore, 
the distance between the parallel opposed horizontal surfaces 74, 82 is 
defined by the width "Z" and identified by the reference numeral 87. 
One of the main features of the calendar resides in the construction of the 
track and the receiving groove. The track is designed in the preferred 
embodiment illustrated, to form a right angle. The width X is sufficient 
to receive the vertical portion in a snug but not overly tight fit. In the 
same fashion the width Y is sufficient to correspond to the length of the 
upper surface 40 of the horizontal portion 38 of the track. When it is 
desired to place the date column on the track or remove it, the 
appropriate groove is selected and the track is received within the 
groove. The angle is sufficient to retain the track at all times, 
including in the position shown in FIG. 6 where the main body member 12 is 
in a forward horizontal position to the ground. 
It is understood that several design considerations must be reviewed in 
order that this construction work properly. Among these considerations are 
the fact that the track in its preferred embodiment may be lipped, but it 
can ba a single straight or curved element, as long as the end portion 
furthest from the back wall terminates at an angular direction which is 
upwardly from the perpendicular axis 43. Furthermore, this angle in the 
upward direction, can be no less that 90 degrees for obvious reasons. The 
more practical constructions will consist of a two element unit as shown, 
or it may consist of an inverted wedged shaped element substantially 
forming a trapezoid with the back wall, or it may consist of a horizontal 
element, and then a wedged shaped element with the inner surface extending 
diagonally upwardly. Another possible construction would be a curved 
chordal member resembling a portion of a washer. Any of these 
constructions are adequate as long as the vertical date column may be 
easily retained securely to said main body member, but may be easily 
removed, when so desired. Futhermore, the date members may easily be slid 
horizontally along the track. 
It has been found that the orientation of the engaging faces accounts for 
the date columns being retained against falling when the calendar is 
tilted forward. Specifically, at least a portion of the engaging surface 
on the track does not face upward (i.e. it is either parallel to front 
wall 34 or faces at least partially downward). This result is not achieved 
in the prior art, where the track includes no such engaging surface. This 
is assured if that portion is constructed so that lines normal to the 
surface at that point and directed away from the surface have no upwardly 
directed component. 
It will be appreciated that a similar result is achieved if the track 
extends rearwardly from the date column and has a downward lip and the 
groove is in the main body, as long as the engaging surfaces have this 
above defined relationship. 
With the described embodiment, date columns may be removed or rearranged 
simply by placing a finger at the bottom of the end piece and pushing 
upwardly until the column drops out. At the same time, the construction 
prevents the columns from falling or becoming detached, as previously 
mentioned, which otherwise occurs quite often when the calendar is being 
changed or when it is being examined for possible purchase. 
Owing to the ease and simplicity with which the columns may be removed, a 
minimum of columns have to be repositioned at any one time in order to set 
up the calendar for a new month, the rest of the columns sliding to the 
left or to the right along the track. 
One arrangement utilized in U.S. Pat. No. 4,142,311 for adjusting for month 
length is illustrated in FIG. 2 where there is shown a date column 26"a" 
normally ending in the numeral 22, 23 or 24 and to which is secured a 
rotatable mounting structure or end piece 29. The mounting structure 
consists of a basically rectangular piece 26"a" which is essentially of 
the same cross-sectional dimensions as the column 26"a". Protruding above 
the structure is a ridge 65 running the entire length of the structure 
which ridge mates with a groove 67 having a conforming shape and size. A 
screw 62 on which is concentrically mounted a spring 64 extends upwardly 
through a hole in structure 29 and is secured into the bottom of the date 
column. In operation the screw 62 is adjusted so that spring 64 exerts a 
sufficient force between the head of screw 62 and structure 29 to maintain 
the ridge 65 in contact with groove 67, while permitting free rotation of 
structure 29 with respect to screw 62 and the date column to achieve month 
length adjustment. Such rotation is achieved by pulling end piece 29 
downward against spring 64 to withdraw ridge 65 from groove 67 while 
twisting the end piece. 
Although the structure 29 provided a useful solution to the month length 
problem, it proved commercially feasible only for relatively expensive 
calendar displays made, for example, of wood. A preferred calendar 
construction for mass production would have date columns (and probably the 
entire calendar) molded from a plastic material. The structure 29 then 
becomes too complex for simple mass production and could require time 
consuming hand assembly. Alternate structures for solving the month length 
problem were therefore sought. 
FIGS. 7-9 illustrate one presently preferred structure for solving the 
month length problems. There is shown a date column 114 which may be 
substituted for any of these three longer date columns 26a, 26b and 26c in 
FIG. 1. Secured at the bottom of the date column 114 is a rotatable end 
piece 129. In FIG. 7, date column 114 and end piece 129 are viewed from 
the rear, so that the date indicia are not visible. As will be appreciated 
from the preceding description, however, date column 114 will bear the 
indicia of one of column 26a, 26b or 26c on its front face, and end piece 
129 will bear the indicium 29, 30 or 31 on one face and will be blank on 
its other face. This construction will permit rotation of end piece 129 to 
adjust for month length. 
Date column 114 could be made of a plastic material, for example, by 
molding. It is essentially a hollow, rectangular block. Column 114 
includes a bottom wall 116, provided with an upwardly extending, 
countersunk bore 118 which, at it innermost extreme, has a portion 119 of 
reduced diameter defining an inwardly directed flange. In addition, column 
114 includes the cutouts 120, 120 in bottom wall 116 which extend through 
the rear of column 114. Each cutout 120 includes an inwardly directed 
protrusion 122 at its rear. 
End piece 129 includes an upwardly projecting shaft 130 having a 
circumferential groove 132. Shaft 130 is dimensioned to be journaled 
within bore 118 of column 114 and groove 132 is positioned and dimensioned 
to receive the flange portion 119 of bore 118 when shaft 130 is mounted 
inside the bore (see FIGS. 8 and 9). To one side of the shaft 130, end 
piece 129 includes an upwardly projecting lug 134 positioned to be 
received in the passageways 120, 120 when end piece 129 is mounted to 
column 114 and properly rotated. Lug 134 is positioned to interfere 
slightly with the protrusions 122 when end piece 129 is rotated to bring 
the lug into one of the cutouts 120, but to fit freely in the inner 
portions of the cutouts. 
Owing to the construction of column 114 and end piece 129, these two 
elements can be assembled readily. It is only necessary to insert shaft 
130 into bore 118 and press end piece 129 upward until flange portion 119 
enters groove 132. Column 114 is preferably made of a resilient material 
(plastic) so that flange 119 is deformed when shaft 130 is inserted into 
bore 118. When flange 119 is aligned with groove 132, its resilience 
causes it to enter groove 132, thereby locking shaft 130 within bore 118. 
The fit of shaft 130 within bore 118 and of flange portion 119 within 
groove 132 are then such that end piece 129 may be rotated freely with 
respect to column 114. 
Lug 134 cooperates with the cutouts 120, 120 to lock end piece 129 in 
either of two positions of rotation with respect to column 114: in one 
position the indicium on end piece 129 is visible from the front of the 
column, and in the other position the blank face is visible. Locking is 
achieved by rotating end piece 129 so as to urge lug 134 into one of the 
cutouts 120. Initially, some resistance is encountered, because lug 134 
interferes with the protrusions 122,122. After the lug is "snapped" past a 
protrusion within a cutout, it is retained within the inner portion by the 
protrusion. 
Turning now to FIGS. 10 and 11, there is shown an alternate construction 
for contending with the month length problem. In this construction, the 
date column 214 is formed with a rabbet 216 at its rear lower end and an 
end piece 229 is pivotally mounted at the lower end of the date column so 
as to be retractable by being pivoted rearwardly and upwardly to the 
position shown in FIG. 11. With end piece 229 in its retracted position, 
its rear and side surfaces are flush with those of date column 214 so as 
to give the appearance of a single block. When the end piece 229 pivoted 
downwardly to its extended position, the face including the indicium (in 
this case the number 31, is flush with the front face of date column 214. 
And the month length is thereby extended. 
Pivotal mounting of end piece 229 to date column 214 is achieved by means 
of a hinge joint comprising the barrel-like protrusion 218 at the bottom 
and rear of the date column and the protruding ears 220, 220. The ears 
220, 220 and the protrusion 218 have aligned bores through which a hinge 
pin 222 is inserted. Preferably, the pin 222 has a slight interference fit 
within the bores, so that the end piece 229 is held in its retracted 
position by friction and will not drop accidentally. On either side of the 
protrusion 218, the bottom of column 214 is provided with a contoured 
rabbet 224 shaped to receive one of the ears 220 (see FIG. 10), while 
permitting free rotation of the ears therein. 
FIG. 12 illustrates an alternate form of the construction illustrated in 
FIGS. 10 and 11. In this version, a date column 314 is provided with a 
rearwardly directed rabbet 316 at its lower end, similar to the rabbet 216 
on column 214. An end piece 329 is pivotally mounted to column 314 at its 
lower rear corner by means of an integral or "living" hinge 318 comprising 
a strip of flexible material joining the date column and end piece 
together. The end piece 329 is therefore movable from its retracted 
position (shown in phantom in FIG. 12) to its extended position (shown 
solid). In each position, the end piece 329 is retained against movement 
by means of a bulbed protrusion 320 which is engagingly received in a 
tapered recess or aperture 322. The apertures are tapered in the sense 
that their openings have a smaller diameter than their interiors. The date 
column and end piece are preferably made of somewhat resilient material, 
such as plastic, which assures the flexibility of the hinge member 318, as 
well as the reduced size openings of the apertures 322, 322. The 
resilience of the aperture openings permits them to deform when one of the 
protrusions 320 is pressed into the opening, thereby permitting the 
protrusion to enter into the aperture and to be retained therein. 
If desired, a calendar construction could be fabricated with only one 
column having a reversible mounting structure 58 secured thereto which 
would carry the numeral "31" on one of its faces. This would be sufficient 
for all the months of the year except February, for which the numerals 
"29" and "30" would always be exposed. However, this deficiency would be 
compensated by a reduction in complexity and cost of manufacture. If 
desired, a second column could carry a reversible mounting structure for 
the numeral "30". 
A series of operational steps will now be described. Assuming the month is 
June, 1976, the calendar is suitably supported, and then the month display 
members 22 are arranged in receptacle 20 so that indicia 22a showing 
"JUNE" is upwardly oriented and forwardly displayed. Other month display 
members 22 are placed rearwardly of "JUNE" and thereby stored. 
Since the first day of June, 1976 is on a Tuesday, the date column 26a 
showing a "1" is placed at the uppermost point of date column area 30 
under the weekday indicia 24 designated "T" (for Tuesday). Consecutively, 
date columns 26b, 26c, 26d, 26e are placed at the uppermost points of date 
column area 30 under the weekday indicia designated "W", "T", "F", "S", 
respectively. Date columns 26f, 26g, are placed under designations "S" and 
"M" at the beginning of the week, but with single voids left at the top of 
each of those date columns to denote that no date on those columns occurs 
during the first calendar week of June, 1976. The arrangement of the two 
track openings 86, 88 of date columns 26f, 26g, and the arrangement of 
tracks 36, allows this configuration. 
It is next determined that June, 1976, has only thirty days, so that the 
adjustable end piece including the numeral 31 days, so that the adjustable 
end piece including the numeral 31 is rotated or retracted to its blank 
display. 
The above clearly illustrates a convenient, simple, yet truly permanent 
calendar structure which may be formed of any one of a number of 
attractive materials. 
While there have been shown and described preferred embodiments of the 
present invention, it is apparent that numerous alterations, omissions and 
additions may be made without departing from the spirit thereof as defined 
in the accompanying claims.