Modular beverage holder

1. A beverage container holder comprising:

a. a base;

b. an upright extending from said base;

c. an extension slide, slidably attached to said upright;

d. a receiver attached to said extension slide;

e. a cup holder attached to said receiver;

f. a locking mechanism for selectively locking and unlocking said extension slide to said upright, thereby allowing an adjustment of a selectable separation distance between said base and said receiver;

g. wherein said locking mechanism is configured so that it is possible to release said locking mechanism and adjust said separation distance using only one hand; and

h. a release button on said receiver, said release button releasing said locking mechanism when pressed.

2. A beverage container holder as recited in claim 1 , wherein said cup holder is removable.

3. A beverage holder as recited in claim 1 , wherein said receiver is rotatably adjustable with respect to said base.

4. A beverage holder as recited in claim 1 , wherein:

a. said upright is a hollow tube having an inside diameter;

b. said extension slide is a hollow tube having an outside diameter; and

c. said outside diameter of said extension slide is a sliding fit within said inside diameter of said upright.

5. A beverage holder as recited in claim 4 , further comprising:

a. wherein said extension slide has an upper end and a lower end;

b. an expanding mandrel attached so said lower end of said extension slide;

c. said expanding mandrel being changeable between a loaded state in which said expanding mandrel expands outward and a relaxed state;

d. a biasing spring tending to bias said expanding mandrel toward said loaded state; and

e. a release rod slidably contained within said extension slide, said release rod having a release button on a first end, said release button being operable to change said expanding mandrel to an unloaded state when pressed.

6. A beverage holder as recited in claim 5 , further comprising:

a. an expansion cone located inside said expanding mandrel, said expansion cone being connected to a second end of said release rod; and

b. wherein said biasing spring tends to force said expansion cone further into said expanding mandrel, thereby expanding said mandrel.

7. A beverage holder as recited in claim 1 , wherein:

a. said upright is a ladder frame having a plurality of transverse windows; and

b. said extension slide is a hollow C-section that is a sliding fit over said ladder frame.

8. A beverage holder as recited in claim 7 , further comprising:

a. An actuator slidably attached to said extension slide, said actuator having an upper end located in said receiver and a lower end;

b. wherein said actuator includes a flex tang proximate said lower end, said flex tang including at least one protrusion configured to engage one of said transverse windows in said ladder frame.

9. A beverage holder as recited in claim 8 , wherein:

a. said flex tang includes a locked position in which said at least one protrusion engages one of said transverse windows and a free position in which said at least one protrusion does not engage said transverse window; and

b. said actuator includes a release button on said upper end that, when pressed, changes said flex tang from said locked position to said free position.

10. A beverage holder as recited in claim 7 , wherein:

a. said extension slide can be slidably engaged to said ladder frame in a first orientation; and

b. said extension slide can be slidably engaged to said ladder frame in a second orientation that is rotated 180 degrees from said first orientation.

11. A beverage container holder, comprising:

a. a base, configured to slide beneath a mattress of a bed;

b. an upright extending from said base;

c. an extension slide attached to said upright;

d. a receiver attached to said extension slide;

e. a cup holder attached to said receiver;

f. a locking mechanism for selectively locking and unlocking said extension slide to said upright, thereby allowing an adjustment of a selectable separation distance between said base and said receiver; and

g. wherein said locking mechanism is configured so that it is possible to release said locking mechanism by depressing a release button.

12. A beverage container holder as recited in claim 11 , wherein said release button is located on said receiver.

13. A beverage container holder as recited in claim 11 , wherein said cup holder is removable.

14. A beverage holder as recited claim 11 , wherein said receiver is rotatably adjustable with respect to said base.

15. A beverage holder as recited in claim 11 , wherein:

a. said upright is a hollow tube having an inside diameter;

b. said extension slide is a hollow tube having an outside diameter; and

c. said outside diameter of said extension slide is a sliding fit within said inside diameter of said upright.

16. A beverage holder as recited in claim 11 , further comprising:

a. wherein said extension slide has an upper end and a lower end;

b. an expanding mandrel attached so said lower end of said extension slide;

c. said expanding mandrel being changeable between a loaded state in which said

expanding mandrel expands outward and a relaxed state;

d. a biasing spring tending to bias said expanding mandrel toward said loaded state; and

e. a release rod slidably contained within said extension slide, said release rod having a release button on a first end, said release button being operable to change said expanding mandrel to an unloaded state when pressed.

17. A beverage holder as recited in claim 16 , further comprising:

a. an expansion cone located inside said expanding mandrel, said expansion cone

being connected to a second end of said release rod; and

b. wherein said biasing spring tends to force said expansion cone further into said

expanding mandrel, thereby expanding said mandrel.

18. A beverage holder as recited in claim 11 , wherein:

a. said upright is a ladder frame having a plurality of transverse windows; and

b. said extension slide is a hollow C-section that is a sliding fit over said ladder frame.