US3415586A - Cabinet shelf elevator and control - Google Patents

Description

Dec. 10, 1968 J HAMMOND 3,415,586

CABINET SHELF ELEVATOR AND CONTROL Filed June 12, 1967 2 Sheets-Sheet 1 lOu k llo lm/ ll lle l-Ob nwm m INVENTOR. JAMES F. HAMMOND ll BY FIG.2 wwfzvy ATTORNEYS Dec. 10, 1968 .1. F. HAMMOND CABINET SHELF ELEVATOR AND CONTROL Filed June 12, 1967 2 Sheets-Sheet 2 lOb -iiiIInumiiiiiiiilm ii lOb I00 FIG.3

INVENTOR. JAMES F. HAMMOND ;ORNEYS M w i a m 4 MN IAAPC. m 5 M a a F 9T1- 2i o United States Patent 3,415,586 CABINET SHELF ELEVATOR AND CONTROL James F. Hammond, 17 Pleasant St., Apt. 1, Los Gatos, Calif. 95030 Filed June 12, 1967, Ser. No. 645,343 Claims. (Cl. 312-312) ABSTRACT OF THE DISCLOSURE Cabinet structure provided with an outer shell and shelf structure slidably supported in the shell by webs which are adapted to be wound on a motor driven roller. The motor and an electromagnetic brake provided thereto are both adapted to be energized when the shelf structure is being raised. Only the electromagnetic brake is adapted to be energized when the shelf structure is being lowered by gravity. A flexible cable is provided for controlling the double pole. double throw switch which is positioned on the motor casing so that this switch may be operated from a remote point to control the raising and lowering of the shelf structure.

This invention relates to cabinet structure provided with a unit for raising and lowering the shelves thereof.

An object of this invention is to provide an improved shelf raising and lowering unit for cabinets such as are used in a home, apartment or the like so that the upper shelves of the cabinet may be lowered for convenient access thereto.

Another object of this invention is to provide an improved shelf raising and lowering device which is adapted to be electrically energized and which is provided with a flexible cable for remote operation of the control switch thereof so that the unit may be completely wired and made available as such to cabinet makers who simply attach the mechanical parts thereof to the cabinet and it is unnecessary for such cabinet makers to install electric wiring required for the unit to become operative.

Still another object of this invention is to provide an improved cabinet structure in which the shelves may be raised or lowered and in which the shelf structure is provided with members slidably engaging front rails attached to the outer shell of the cabinet structure which prevents the outer shell from expanding and eliminates the necessity for providing bridging members across the front of the cabinet shell to hold the cabinet shell, particularly the lower front thereof, from abnormally spreading apart.

Another object of this invention is to provide an improved shelf raising and lowering unit to cabinets such as are used in the home, apartments or the like, said unit being provided 'with webs which are attached to the opposite sides of the shelf structure, said webs being adapted to be wound on a roller and interleaved during the winding thereof on the roller so that uniform pull is exerted by the roller on both webs, whereby uniform lifting action is provided to the opposite sides of the shelf structure during the raising and lowering thereof.

Other and further objects of this invention will be apparent to those skilled in the art to which it relates from the following specification, claims and drawings, in which, briefly:

FIG. 1 is a perspective view of an embodiment of this invention, partially broken away, with the shelf structure shown in solid lines in elevated position, and' in broken lines in lowered position;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1

FIG. 3 is a top view of an embodiment of the shelf raising and lowering apparatus of this invention;

FIG. 4 is a fragmentary view taken along the line 44 of FIG. 3 showing the upper limit switch; and

FIG. 5 is a diagram of electrical connections employed in this apparatus.

Referring to the drawing in detail, reference numeral 10 designates the outer shell of a cabinet structure such as is employed in kitchens of homes, apartments and the like. This cabinet structure is provided with inwardly extending front rails 10a that are attached to the front edges of side walls 10b. The rails 10a are each provided with a groove on the inside thereof for receiving the members 11a which are attached to the shelf structure 11.

The shelf structure 11 is provided with several shelves 111), one of which functions as the bottom thereof, and these shelves are attached to the side walls 11c and back panel 11d. The members 110, which are slidable in the grooves 100, function to restrain the side walls 11b from spreading since no bottom member is provided to the outer shell 10. The shelf structure 11 is slidable up and down in the outer shell 10 so that the shelves 11b thereof may be raised or lowered to provide easy access to the upper shelves thereof. :No cross pieces are provided between the rails 1011 so that the operators fingers cannot be caught between the shelves 11b and the shell structure 10 during raising or lowering of the shelves.

A shelf 12 is provided in the shell structure 10 near the upper end thereof to form a compartment with the upper portions of the sides 10b and back 10d for receiving the shelf elevating and lowering unit 13. The shelf raising and lowering apparatus 13 is provided with a conventional fractional horse power motor and speed reducing gearing. An output shaft 15 is provided to the reduction gearing and this shaft is rotated at a relatively slow speed of one or two r.p.m. Roller 16 is fixedly attached to shaft 15. Webs 17 and .18, which may be made of any flexible material such as canvas, having suitable strength, are provided for raising and lowering the shelf structure. One of the ends of each of the webs is attached to the roller 16 so that these webs may be wound on the roller 16 when this roller is driven by the motor and speed reduction gearing 14. The lower ends of the webs 17 and 18 are attached to the sides 110, as shown for example at 18a. Suitable rollers 19 and 20 are attached to the respective ends of the shelf or platform 12 and the webs 17 and 18 ride over these respective rollers during the raising and lowering of the shelf structure .11.

One end of the motor shaft 21 extends outward from the motor housing and is provided with a wheel 22 which is fixedly attached thereto. The wheel 22 may be made of suitable plastic material such as nylon, Delrin or the like. The armature 23 of the electromagnet 24 is adapted to be spring-pressed by a spring 23a against the plastic wheel 22 to prevent the motor shaft 21 and the shaft 15 from turning when the shelf structure 11 is in elevated position and the motor is deenergized.

The diagram of connections employed in this apparatus is shown in FIG. 5. The double pole double throw switch 25 which is mounted on the motor and gear apparatus 14 is remotely controlled by the flexible cable 25a. This cable is positioned in the tube 25b which extends bet-ween the sides 10b and of the cabinet structure, and the lower end thereof extends slightly below the shell 10, as shown in FIG. 1. This lower end is provided with a small knob 250 which is attached to the cable 25a. Thus, the switch 25 may be operated by either pulling or pushing on the knob 250. Two limit switches 26 and 27 are provided to this apparatus. Limit switch 26 is attached to the shelf 12 as shown in FIG. 4 and is provided with an actuating member 26a which is adapted to be engaged by the upper edge of the back panel 110! of the shelf structure when this structure is in its upper position so that the switch 26 is open. Limit switch 27 is provided for limitng the downward movement of the shelf structure and this switch is attached to a bracket that is attached to the top of the motor and reduction gear unit 14. A cable or cord 27a has one end thereof attached to the arm of switch 27 and the other end thereof attached to the web 18, as shown in FIG. 3. When the shelf structure 11 is in its down position web 18 extends the cord 27a, as shown by the broken line in FIG. 3, and switch 27 is opened thereby.

When the blades 28 and 29 of double pole double throw switch 25 are in their upper position as shown in FIG. 5 in which they make contact with the upper contacts of the switch, the motor 14a and electromagnetic brake 24 are energized if the shelf structure 11 is in its down position or partially lowered so that the back panel 11d thereof is clear of switch 26 and this switch is closed. The motor and gear arrangement 14 then function to drive the roller 16 and wind the webs 17 and 18 thereon to raise the shelf structure 11 until the back panel 11d of the structure engages the actuating member 26a of the limit switch 26 and opens this switch.

When switch 26 is open, both the motor 14a and the electromagnet winding 24 of the brake are de-energized. Armature 23 of the electromagnetic brake is then pressed by the spring 23a against the wheel 22 to prevent it and the shaft 21 of the motor from rotating. The shelf structure 11 cannot be lowered by gravity as long as the brake engages the wheel 22. When the operator desires to lower the shelf structure 11 from its up position he pulls down on the button 250 which is attached to cable 25a and shifts the switch blades 28 and 29 of switch 25 to engage the lower contacts of this switch, as shown in FIG. 5. Only blade 28 is active in this position, as will be seen from an examination of FIG. 5, and this blade connects the switch 27 to the one side of the current supply line. Switch 27 is closed when the shelf structure is in its up position inasmuch as the actuating cable 27a thereof is in relaxed position. Winding 24 of the brake is energized through switch 27 and the armature 23 of the brake is retracted from the wheel 22, thus releasing the brake and allowing the shaft 21 of the motor to rotate. Shelf structure 11 is then allowed to be lowered by the force of gravity thereon until the web 18 is extended and tension applied to the cord 27a, which functions to open switch 27. Winding 24 of the electromagnetic brake is then de-energized and the armature 23 thereof released so that it is pressed by spring 23a against the wheel 22 which is restrained from further rotation. The shelf structure is now in its down position and, in order to raise it, the operator pushes knob 250 up to move the blades 28 and 29 to their up position and connect the motor and brake winding to the current supply through switch 26, and the raising operation described is repeated.

One of the features of this invention resides in the fact that this shelf raising apparatus may be provided as a unit which may be installed by cabinet makers and the current supply connection thereto may be plugged into a conventional wall electric outlet. For this purpose the switch 26 may be attached to the motor unit by a suitable bracket which also encloses the wiring to this switch.

While -I have shown a preferred embodiment of this invention, it will be understood that the invention is capable of variation and modification from the form shown so that the scope thereof should be limited only by the proper scope of the claims appended hereto.

What I claim is:

1. In apparatus for raising and lowering the shelves of a cabinet, the combination of cabinet structure having an outer shell including side walls having the rear edges thereof attached to a back panel, and shelf structure slid- Cit able up and down in said outer shell, said shelf structure having side walls and a back panel and a plurality of shelves attached thereto, a pair of webs, means attaching the bottom ends of said webs to the outer sides of said side walls of said shelf structure so that parts of said webs are positioned between the side walls of said shelf structure and said outer shell, a roller, means including an electric motor for driving said roller, means attaching the top ends of said webs to said roller, said webs being adapted to be wound on said roller when said roller is driven by said motor for lifting said shelf structure in said outer shell, electromagnetic brake means associated with said electric motor preventing downward travel of said shelf structure by force of gravity when said motor is de-energized, switch means connecting said motor and said electromagnetic brake to a source of current supply to energize said brake and said motor when said shelf structure is raised, said switch means having means connecting said brake only to said source of current supply to energize said brake when said shelf structure is lowered by gravity.

2. In apparatus for raising and lowering the shelves of a cabinet, the combination as set forth in claim 1 further characterized in that said outer shell of said cabinet structure is provided with inwardly extending rail members attached to the front edges of said side walls of said outer shell, and the front edges of said side walls of said shelf structure being provided with members slidable in grooves formed in said rails to hold said side walls of said outer shell close to said side walls of said shelf structure.

3. In apparatus for raising and lowering the shelves of a cabinet, the combination as set forth in claim 1 further characterized in that remote control means in the form of a flexible cable is attached to said switch means for the remote actuation of said switch means.

4. In apparatus for raising and lowering the shelves of a cabinet, the combination as set forth in claim 1 further characterized in that there is provided a support in the top part of said cabinet above said shelf structure for supporting said motor and said roller, and a limit switch connected to said motor, said limit switch being adapted to be opened by said shelf structure when said shelf structure is raised to disconnect said motor and said brake means, and another limit switch connected to said brake means, said last mentioned limit switch being adapted to be opened when said shelf structure is down.

5. In apparatus for raising and lowering the shelves of a cabinet, the combination as set forth in claim 1 further characterized in that said brake means comprises a wheel attached to the shaft of said motor, an electromagnet and an armature associated with said electromagnet, a spring pressing said armature against said Wheel when said electromagnet is de-energized to prevent said motor shaft from turning, said armature being pulled away from said wheel against the tension of said spring when said electromagnet is energized to permit the shelf structure to be lowered by gravity.

References Cited UNlTED STATES PATENTS JAMES T. MCCALL,

US. Cl. X.R.

Prinmry Examiner.

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