Table leg lock

This invention comprises an improved mechanism for latching telescoping articles together and for releasing them from such a condition by the act of rotating them with respect to each other. The mechanism includes a pair of pawls interconnected to each other by a spring in such a manner that the latch heads of the pawls are urged in a plane in opposite directions by action of the spring. The invention is illustrated and described in the context of a table which is mounted to the floor of a vehicle, vessel or the like.

FIELD OF THE INVENTION 
This invention relates to a means to secure a single leg table, more 
generally referred to as a pedestal table, to a base and more particularly 
to a means to secure a pedestal table to the flooring of a van, mobile 
home, recreational vehicle, or the like. 
BACKGROUND OF THE INVENTION 
Vans, mobile homes and recreational vehicles, generally referred to as RVs, 
have long been fitted with tables. Such tables serve the same purpose and 
use as do tables in conventional homes, but are designed so to fit into 
the confined, constricted or limited space within such vehicles. Normally 
such tables include center pedestals which are wedged into floor mounted 
socketed bases. 
In the event of an accident, these tables can become airborne and are 
extremely dangerous to the occupants of the vehicle. Indeed, there have 
been numerous and sometimes fatal injuries inflicted by such tables. It 
has accordingly been desirable to design and structure the tables so that 
they may be removed and stored in a secure and safe portion of the vehicle 
(or to be removed completely and left at home). Furthermore, means should 
be developed whereby such tables may be secured to the vehicle to prevent 
them from becoming airborne in an accident. 
The present invention is directed to a simplified, inexpensive, yet safe, 
means for securing a table to, and releasing it from, a base portion which 
is fitted in the floor of the vehicle. 
It will be understood that, although the principal utility of this 
invention is in the illustrated environment, it should not be so limited. 
It will find essentially the identical utility on vessels and fishing 
craft, and even in aircraft, as will be obvious from the description. An 
example of the former would be the seat on the increasingly popular "bass 
boat." Also, it will find utility on porches or decks and on piers or 
docks. 
SUMMARY OF THE INVENTION 
The present invention provides a self contained latching system, located 
within the pedestal leg, which may be actuated by a mere twist of the 
pedestal leg. There are preferably two virtually identical latching 
mechanisms, each comprised of a spring pawl. One latching mechanism 
secures the pedestal leg to the floor and the second latching mechanism 
secures an object such as a table top to the pedestal leg. The table is of 
conventional design and structure and the base, which accepts the pedestal 
leg, is also of relatively conventional design and structure. 
The present invention relates to the means for securing and latching the 
pedestal leg to the base and to an object. To actuate the latch, the 
pedestal leg is rotated in one direction; to deactivate the latch, the 
pedestal leg is rotated in the opposite direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
A table supported by a single leg, as opposed to three or four, is 
generally referred to in the trade as a pedestal table. In the classical 
sense, a pedestal is the support or foot of a column, or the part on which 
an upright work, e.g., a statue, stands. In an engineering sense, a 
pedestal is a support which carries, e.g., a bridge truss or girder, and 
transmits the load it receives to the top of a pier or abutment. 
It is in this latter sense that I herein refer to the structure as a 
pedestal. For purposes of explanation, however, I shall borrow from both 
the classical and the mechanical and refer herein to the lower support as 
the base, to the column as the leg and to that fixture which supports the 
table as the surbase. 
Referring now to the figures, the invention is illustrated as a latching 
means within a pedestal depicted as a support 10 for table 12. Support 10 
includes a surbase 20 fixed to table 12, a base 30 fixed to floor 14, and 
a leg 40, extending therebetween and functioning to support table 12 a 
desired distance above floor 14. 
Other than as modified to receive the present invention, base 30 and 
surbase 20 are relatively standard supporting fixtures and will be 
described herein only to that extent necessary to accommodate and accept 
the latching means. 
Surbase 20 is structured so to fit flush against table 12 and to extend 
downwardly a sufficient distance, and to be socketed to accept leg 40. 
Fastener holes 22 are provided for accommodating screws 23 used to secure 
surbase 20 to table 12. Base 30 is structured so to fit relatively flush 
with the surface of floor 14 and to extend therethrough. Base 30 socketed 
so to accept leg 40 and is of sufficient strength and stability to support 
leg 40 and attached table 12. Fastener holes 32 are provided in base 30 in 
order to accommodate screws 23 used to secure the base to the floor 14. 
It will be appreciated that base 30 and surbase 20 are meant to be secured 
with relative permanence to floor 14 and table 12 respectively, and that, 
for purposes of storage and convenience, leg 40 is meant to be detachable 
from both. Leg 40 is of sufficient strength and rigidity to support table 
12. 
Leg 40 is generally symmetrical in shape and preferably tapered at both 
ends. The reason for this is to avoid a situation where there is a "top" 
or "bottom", one of which must be fitted to base 30 and the other to 
surbase 20. Configured symmetrically, either end may be inserted into 
either base 30 or surbase 20. 
Since both ends of leg 40 are of the same construction, only one end of leg 
40 need be described in detail. It should be obvious, however, that if 
there is a reason for the ends to be configured differently one from the 
other, such minor modification can be effected without departing from the 
invention. 
There is an additional reason for this symmetry, and that has to do with 
base 30. As previously noted, the pedestal table is illustrated in the 
environment of a van, mobile home or RV. In such an environment, space 
exists below the floor of the vehicle to accommodate a base which extends 
therethrough. Indeed, it is desirable in such an environment to have a 
flush-fitting base for safety, one over which a person is not likely to 
trip. In another environment, e.g., a vessel or water craft, not having a 
deck per se, it may be imprudent to create an opening in the "floor." In 
such an environment, it may be desirable to secure to the floor a base 
having the shape and configuration of the surbase, i.e., flush-mounted. It 
is accordingly preferred that leg 40 be symmetrical and that these 
portions of base 30 and surbase 20 which receive the ends of leg 40 be 
configured so that the respective bases are interchangeable. 
The latching mechanism, identified by the numeral 50, falls within a class 
of devices which may be generically referred to as spring pawls. In this 
instance, latching mechanism 50 includes a pair of spring pawls, motivated 
by a single helical spring which urges the pawls to move in opposite 
directions one from the other into a latching condition. More 
specifically, and referring to the figures, latching mechanism 50 consists 
of two symmetrical pawls 52 united in movement by helical spring 80 in 
such a fashion as to be urged away from one another in the same plane. 
Once again, because they are symmetrical, and in order to simplify the 
description, one pawl only will be described in detail. 
Each pawl 52 is a unitary strip of metal having what will be herein 
identified solely for descriptive purposes as a foot 56, arms 58, and a 
head 60, best seen in FIG. 2. Foot 56 is bent at a general right angle. 
Head 60 at its tip 100 is of an arcuate shape. The arms 58 are preferably 
of the same general length and are rounded at shoulder surfaces 70, 72 to 
conform to the inner diameter of wall 90 of leg 40. Head 60 from shoulder 
surface 70 extends outwardly along the axis of the head a distance 
approximating the thickness of wall 90 plus the thickness of wall 92 of 
the receiving portion of base 30. This ensures adequate insertion of the 
tip into the slots. Head 60 extends from arm surface 72 outwardly along 
the axis of the head a distance equal to the thickness of wall 90 of leg 
40. 
Tip 100 of head 60 maintains a curved shape generally conforming to the 
outer circumference of wall 92 for approximately one half its extent and 
then is chamfered to meet the outer circumference of wall 90. Wall 90 of 
leg 40 has two slots 110, 112 located opposite each other and of lengths 
conforming to the cross-sectional dimensions of tips 100 of heads 60 of 
pawls 52. Slots 110, 112 are equidistant from end 42 of leg 40. It must 
here be recalled that it was stated previously that the ends of leg 40 
were symmetrical and that, when one end is described both are described. 
It will accordingly be understood that when we say two slots we mean that 
there are two slots at each end of leg 40, a latching mechanism 50 at each 
end. 
Each pawl 52 along its longitudinal dimension is offset slightly 
immediately before head 60 and in a direction opposite foot 56. This 
offset is such that when pawls 52 are mated with each other and assembled 
with helical spring 80 to form latching mechanism 50, heads 60 are 
accordingly in the same plane. 
Helical spring 80 is compressed between heads 60 of pawls 52 so that the 
heads 60 of latching mechanism 50 are urged away from each other. Spring 
80 is of a diameter closely approximating the width of each pawl 52. Foot 
58 of each pawl protrudes between turns of spring 80 to prevent separation 
of the pawls during assembly of the latching mechanism 50 into the leg 40. 
The combination of a pair of pawls 52, surrounded by helical spring 80, 
results in a completely self-contained, self-actuating latching mechanism 
50. When the latching mechanisms are inserted into leg 40 and heads 60 are 
inserted into slots 110, 112, this action of spring 80 maintains the 
proper location of the latching mechanism heads. 
Referring to surbase 20 and base 30, it will be recalled that, although the 
two are shaped quite differently, these components which receive the ends 
of leg 40 are essentially the same. For purposes of this description, base 
30 will be described and that portion thereof which receives leg 40 will 
be referred to as cup 24 and that portion which receives screws 23 will be 
referred to as mounting flange 25. 
Cup 24 is of a slightly truncated conical shape. End 42 of leg 40 is 
tapered to conform to the shape of cup 24. While this is not an absolute 
requirement, it has been found that such a taper facilitates the insertion 
of leg 40 into cup 24. 
Slots 114, 116 are located opposite from each other in wall 26 of cup 24 
and are shaped to receive the heads 60 of latching mechanism 50. Slots 114 
and 116 are preferably located the same distance from bottom wall 28 of 
cup 24 as are slots 110, 112 located from end 42 of leg 40. All of the 
slots are virtually identical in shape. Tip 100 of head 60 is preferably 
beveled to allow it to be cammed more easily over flange 25 of base 30 
during insertion of the leg. 
With latching mechanism 50 held in place by action of the outwardly urging 
force of spring 80, shoulder surfaces 70 and 72 of the pawls press against 
the inner surface of leg wall 90. To assemble, leg 40 is inserted into cup 
24 to cause heads 60 to be cammed over flange 25 and down wall 26 of cup 
24. As end 42 of leg 40 reaches wall 28 of cup 24, slots 110, 114 and 112, 
116 are at the same level. Leg 40 is then rotated until heads 60 are in 
alignment with slots 114, 116, at which time the pressure exerted 
outwardly by spring 80 causes the heads of latching mechanism 50 to snap 
into the slots in a latching position securing the leg to the base against 
axial separation. 
The shape of tip 100 of head 60 assists in the detachment of the leg from 
the base. FIGS. 3 and 5 depict latching mechanism 50 in its aligned and 
latched condition. As leg 40 is rotated in a clockwise direction, the 
chamfered tips 100 of heads 60 are cammed along the edge of slots 114, 
116, urging pawls 52 inwardly and compressing spring 80, as shown in FIG. 
6. Further clockwise movement of leg 40 causes heads 60 to be cammed 
completely free of slots 114, 116, as shown in FIGS. 4 and 7, and leg 40 
may be lifted from base 30. 
If clockwise turning of tubular leg 40 releases both the latching mechanism 
from base 30 and the latching mechanism from surbase 20, it will be 
apparent that one or both may release at the same time. Because the 
latching mechanism is self-contained, it is reversible. FIG. 2 displays 
the heads 60 of pawls 52 of lower latching mechanism 50 in a condition 
which permits clockwise rotation. Heads 60 of pawls 52 of upper latching 
mechanism 50 are illustrated in a condition which permits anti-clockwise 
rotation. Release of the leg from either the base or surbase can be 
clockwise or anti-clockwise, by choosing a selected inverted or 
non-inverted orientation of the latching mechanism 50 during its assembly 
into the leg. 
In operation, and placed in any suitable environment, table 12 and leg 40 
are in a storage compartment. Surbase 20 is secured to table 12 and base 
30 is secured to the floor. When it is desired that the table be utilized, 
leg 40 is inserted into cup 24 of surbase 20 and latched. Table 12 is 
lifted into its upright position and centered over base 30. Leg 40 is 
inserted into cup 24 of base 30 and rotated until the slots are aligned 
and latching mechanisms 50 spring into position. 
For removal, table 12 is rotated in the opposite direction, the co-action 
between tips 100 of heads 60 of pawls 52 and leg wall 90 effectively cam 
latching mechanism 50 inwardly against the pressure of spring 80 and out 
of engagement with slots 114, 116. Table 12 and leg 40 may then be 
removed, separated and placed in storage. 
It will be understood that the invention is not to be limited to the 
precise form disclosed in the preferred embodiment but may be modified 
without departing from the scope of the invention as defined by the 
appended claims.