US3181921A

US3181921A - Safety and control mechanism for power-operated structure

Info

Publication number: US3181921A
Application number: US341877A
Authority: US
Inventors: Fred W Moore; Jr Robert C Pressley
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1964-02-03
Filing date: 1964-02-03
Publication date: 1965-05-04
Anticipated expiration: 1982-05-04

Description

y 1965 -F. w. MOORE ETAL 3,181,921

SAFETY AND CONTROL MECHANISM FOR POWER-OPERATED STRUCTURE Filed Feb. 3. 1964 3 Sheets-Sheet 1 INVENTORS FRED W. MOORE mafia TTORNEY QROBERT C. PRESSLEY TR.

- 1965 F. w. MOORE ETAL 3,181,921

smawy AND CONTROL MECHANISM FOR POWER-OPERATED STRUCTURE Filed Feb. ":5. 1964 s Sheets-Sheet 2 2o 22 Z l 2s Fl (-3 3 INVENTORS F-RED w. MOORE H 8: ROBERT c. PRESSLEY :12)

' THEIR ATroRmEY May 4, 1965 F. w. MOORE ETAL 3,131,921

SAFETY AND CONTROL MECHANISM FOR POWER-OPERATED STRUCTURE Filed Feb. 3. 1964 :s Sheets-Sheet s Z0 22 Z I F'IGA 13 FIGS INVENTORS FRED w. MOORE BYZROBERT c. PRESSLEY 3R.

H THEIR ATTORNEY United States Patent 3,181,921 SAFETY AND CONTROL MECHANISM FOR PGWER-OPERATED STRUCTURE Fred W. Moore, Louisville, and Robert C. lPressiey, In, Anchorage, Ky., assignors to General Electric Company, a corporation of New York Filed Feb. 3, 1964, Ser. No. 341,877 9 Claims. (Cl. 312-223) The present invention relates to power-operated structures, and more particularly to a safety and control mechanism for such structures.

Many attempts have been made in the past to provide power-operated, movable sections for such apparatus as storage cabinets or the like. However, prior art devices of this type have had deficiencies which limited the commercial adoption thereof. One of the principal problems has been the provision of a satisfactory safety and control mechanism. Such a safety and control mechanism should operate to automatically stop the movable section of the cabinet structure at its extreme positions. The mechanism also should be manually operable to stop the movable section intermediate its extreme positions. Additionally, the mechanism should be responsive to a slight pressure at any point along the length of the cabinet to stop the movable section regardless of the relative position of the sections to ensure that the users hands or other objects will not become caught between the edges of the stationary and movable sections as they come together. Prior art devices have failed to achieve these multiple objectives.

A principal object of the present invention is to provide an improved safety and control mechanism for a powered cabinet or the like.

Another object of the present invention is to provide a safety and control mechanism for a powered cabinet or the like which is effective to automatically stop the movable section of the cabinet at either of its extreme positions.

A further object of the present invention is to provide a safety and control mechanism for a powered cabinet or the like which is responsive to a small pressure at any point along the length of cabinet to stop the movable section of the cabinet.

The present invention, in accordance with one form thereof, includes a cabinet structure having a stationary cabinet section and an adjacent, power-operated, movable cabinet section. A control and safety mechanism is provided for operating a switch to start and stop the movable cabinet section. The mechanism includes separate start levers for causing the movable cabinet section to move in opposite directions and a stop member for stopping the movement of the movable section. The mechanism is interconnected with the movable cabinet section so that, as the movable section approaches either of its extreme positions, the stop member automatically functions to stop movement of the movable section. Additionally, a pressure-responsive release mechanism extends along the entire edge of the junction between the movable cabinet section and the stationary cabinet section. The release mechanism responds to a small pressure exerted at any point along its len th to cause the stop member to stop movement of the movable cabinet section. This ensures Patented May 4, 1965 ice that if any object such as the users hand is inserted between the movable cabinet section and the stationary cabinet section, the movable section is immediately stopped to prevent damage to either the object or the cabinet structure.

This invention will be better understood from the following description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a perspective view of a power-operated cabinet including one embodiment of the present invention, partially broken away and partly in cross-section;

FIGURE 2 is a front elevational view of the control and safety mechanism of FIGURE 1, partly broken away and partly in cross-section to illustrate details;

FIGURE 3 is an end view of the mechanism illustrated in FIGURE 2, partly broken away and partly in crosssection;

FIGURE 4 is an elevational view similar to FIGURE 2, showing one start member in circuit-closed position;

FIGURE 5 is an end view similar to FIGURE 3 but showing one start member in the position of FIGURE 4;

FIGURE 6 is a partial perspective view of the pressureresponsive release mechanism; and

FIGURE 7 is a schematic wiring diagram of the electrical control circuit.

Referring to FIGURE 1, there is shown a cabinet structure 10 including a stationary cabinet section 11 and a movable cabinet section 17:. The movable cabinet section 12 is moved upwardly and downwardly by means of a suitable motor and lift mechanism (not shown). The rear portion of the stationary cabinet section is provided with an upstanding ledge 13 in which is mounted a control and safety mechanism 14 which is utilized to start and stop the motor powering the movable cabinet section in order to control the positioning of the movable cabinet section.

The structure of the control and safety mechanism will be better understood by reference to FIGURES 2 through 5. A switch 15 is mounted in the stationary cabinet section 11 and extends upwardly into an opening 16 provided in the upstanding ledge 13. The switch is a conventional bistable switch including switch-operating

members

17, 13 and 19. The switch-operating members are stable in either their upper position (illustrated in FIGURE 2 by switch-operating members 17 and 18) or their lower position (illustrated in FIGURE 2 by switchoperating member 19). When in their lower position, the

operating members

17 and 18 close contacts (not shown) within the switch 15 to provide electric power to leads 2t) and 21 respectively and function to open these contacts when in their upper position. Switch-operating member 19 functions to close contacts (not shown) within the switch to provide electric power to lead 22 when switch-operating member 19 is in its upper position and to open its associated contacts when it is in its lower position. The switch-operating members are interconnected within the switch so that depression of either of the

members

17 and 13 causes the member 19 to be raised and depression of the member 19 causes the members 17 and 1% to be raised. It will be understood that, by depression of the appropriate one of the switch-operating members, the switch may be set in the off position, in which case no electric power will be provided to the

leads

2Q, 21

and 22, or electric power may be selectively provided to leads and 22 or leads 21 and 22.

The control and safety mechanism 5 for operating the switch-operating

members

17, 18 and 19 is mounted within the opening 16 in the ledge 13 and includes a frame 23 which supports the other parts of the mechanism. A first manually-operable start member 24 and a second manually-operable start member 25 are pivotally mounted within the frame 23. The start members are in the form of levers mounted upon a rod 26 which extends across and is mounted on the rear of the frame 23. The start members or levers include downwardly extending

projections

27 and 28 which are formed to contact and depress switch-operating

members

17 and 18 respectively as the start levers are pivoted downwardly about the rod 26. A stop member in the form of a vertically movable block 29 is mounted within the frame between the start levers. The stop member 29 is positioned between a pair of guides or

brackets

30 and 31. The guides include inwardly extending shoulders 32 and 33 respectively, which extend partially across the front of the stop member 29. The guides effectively constrain the stop member to movement in the vertical direction. The stop member 29 is mounted about a shaft 34 for vertical movement and is biased to its lower position by means of a coil spring 35. When the stop member is moved to its upper position it compresses the coil spring against the frame 23, thus storing energy for moving the stop member to its lower position. When moved to its lower position, the stop member 29 depresses switchoperating member 19 to open the circuit through switch 15.

The first start lever 24 is interconnected with stop member 29 by means of a first trip member 36. The trip member 36. The trip member 36 is pivoted at 37 and in- I cludes an extension 38 which contacts the underside of start lever 24. The opposite end of trip member 36 is formed with a pair of spaced arms 39 and 40. The spaced arms overlie the front and rear faces of the stop member 29. The arms include inwardly extending

pins

41 and 42 which are received in

horizontal slots

43 and 44 in stop member 29 to form an operative engagement between trip member 36 and stop member 29.

In a similar manner the second start member 25 is interconnected with stop member 29 by means of a second trip member 45. The trip member 45 is pivoted at 46 and includes an extension 47 which contacts the underside of start lever 25. The opposite end of trip member 45 is formed with a pair of spaced arms 48 and 49 which overlie the front and rear faces respectively of stop member 29. The arms include inwardly extending pins 50 and 51 which are received in

horizontal slots

43 and 44 in stop member 29 to form an operative engagement between trip member 45 and stop member 29.

In order to latch stop member 29 in its upper, or switch closed position when either of start levers 24 or 25 is pivoted downwardly, stop member 29 is formed to include a notch 52 which is engaged by a spring latch 53. Thus, when either of start levers 24 and 25 is pivoted downwardly to depress one of the switch-operating

members

17 and 18, stop member 29 is moved vertically upward and is latched in its upper position (as shown in FIGURE 5).

In order to disengage spring latch 53 from notch 52 and allow coil spring 35 to move stop member 29 downwardly, spring latch 53 is formed to include a cam arm 54 which is operated by a pressure-responsive release mechanism 55. The pressure-responsive mechanism 55 includes a plunger 56 mounted on a leaf spring 57 which is connected to the top of frame 23 (as best seen in FIGURES 2 and 4). The spring 57 biases plunger 56 to an upper position but is deformable under pressure to move plunger 56 downwardly to engage cam arm 54 and thereby disengage spring latch 53 from notch 52.

Referring now to FIGURE 5, it will be seen that an elongated control bar 58 is provided for depressing leaf spring 57. In order to maintain control bar 58 parallel to upstanding ledge 13 so that the pressure necessary to depress leaf spring 57 is the same over the entire length of the cabinet, control bar 58 is connected to a control bar support member 59 by means of a number of spaced parallel arms 60 which are pivotally secured to control bar 58 and control bar support member 59 by means of rivets 61. The control bar support member 59 is in turn secured to upstanding ledge 13.

The control bar 58 includes a horizontal portion 62 which is disposed under movable cabinet section 12 so as to be contacted by cabinet section 12 as it approaches its extreme lower position to depress leaf spring 57 and to release stop member 29. The horizontal portion 62 is provided with a pair of

extensions

63 and 64 which project outwardly from movable cabinet section 12 adjacent the control and safety mechanism 14 so that the operator may depress the control bar manually without reaching under the edge of the movable cabinet 12.

In order to stop the movable cabinet section 12 as it approaches its extreme upper position, a stop arm 65 is pivotally mounted on control bar support member 59. One end 66 of stop arm 65 extends through an opening 67 in control bar 58 while the other end of stop arm 65 is formed with a foot 68 which projects outwardly from control bar support member 59. Referring now to FIG- URES 3 and 5, it will be seen that foot 68 is disposed above a lower portion 69 of movable cabinet section 12 so that, as the movable cabinet section approaches its extreme upper position, lower portion 69 engages foot 68 and pivots stop arm 65 to lower the control bar 58 and depress leaf spring 57 and plunger 56.

FIGURE 7 is a schematic wiring diagram of the electric control circuit in which the switch 70 represents the contacts controlled by switch-operating member 17, switch 71 represents the contacts controlled by switch-operating member 18 and switch 72 represents the contacts controlled by switch-operating member 19. The leads 20, 21 and 22 connect

switches

70, 71 and 72 to the windings of motor 73. Switches 70 and 71 are closed by depressing switch-operating

members

17 and 18 respectively while switch 72 is closed by raising switch-operating member 19. The open-circuit or motor-off position indicated by FIGURE 7 corresponds to the control and safety mechanism setting shown in FIGURE 2.

Downward movement of first start member 24 to depress switch-operating member 17 closes contact 70 and the interconnection between switch-operating member 17 and switch-operating member 19 causes switch-operating member 19 to rise and switch 72 to be closed. With this setting the motor 73 will rotate so as to move the movable cabinet section 12 upwardly. A subsequent depression of leaf spring 57 and plunger 56 disengages latch 53 from notch 52 and allows coil spring 35 to move stop member 29 to its lower position. This movement of stop member 29 depresses switch-operating member 19 to open switch 72 and the interconnection between switchoperating member 19 and switch-operating member 17 raises switch-operating member 17 and opens switch 70, stopping upward movement of the movable cabinet section 12.

Downward movement of second start member 25 depresses switch-operating member 18 and, in a manner similar to the operation upon downward movement of first operating member 24, results in switches 71 and 72 being closed to provide electrical power to the motor 73 for moving movable cabinet section 12 downwardly. A subsequent depression of leaf spring 57 and plunger 56 causes a depression of switch-operating member 19 and raises switch-operating member 18 to open switches 71 and 72 and stop the movable cabinet section.

Beginning with the cabinets in the position illustrated in FIGURE 1, when it is desired to raise the movable cabinet section 12 the operator merely depresses first start member 24. The projection 27 depresses switch-operating member 17 and the extension 38 is rotated downwardly, pivoting first trip member 36 about pivot 37 and moving stop member 2% upwardly. When stop member 29 reaches its uppermost position, latch 53 engages the notch 52 and holds stop member 29 in its upper position against the pressure exerted by the compressed coil spring 35. The interconnection between switch-operating member 17 and switch-operating member 19 causes switchoperating member 19 to be raised as switch-operating member 17 is depressed, thus closing switches 70 and 72. The motor 73 rotates in a direction to raise movable cabinet section 12. Since second trip member 45 is interconnected with stop member 29, second trip member 45 also will be pivoted downwardly and second start member 25 will move downwardly a short distance until extension 28 comes in contact with switch-operating member 18. However, since switch is a bi-stable switch,

switchoperating members

17 and 18 are biased to both of their extreme positions and switch-operating member 18 will support the weight of second start member 25.

Referring now to FIGURE 6, as movable cabinet section 12 approaches its upper position, lower portion 69 of the movable section contacts the outwardly projecting foot 68 and pivots stop arm 43 to depress control bar 58, thereby depressing leaf spring 57 and plunger 56 and disengaging latch 53 from notch 52. The stop member 29 is thereby released and coil spring 35 forces stop member 29 downwardly, depressing switch-operating member 19. The downward movement of stop member 2h also pivots trip members as and 45 to raise

start members

24 and 25 and the depression of switch-operating member 19 raises switch-operating member 17. Thus switches 74] and 72 are opened to stop the motor and movable cabinet section.

In a similar manner when it is desired to lower the movable cabinet section, the second start member 25 is .moved downwardly and projection 28 depresses switchoperating member 18. The second trip member 45 is pivoted about pivot 46 and raises stop member 29 to its upper position where it is locked in place by latch 53. The switch-operating member 18, also being interconnected with switch-operating member 19, raises switchoperating member 19 as switch-operating member 18 is depressed and thereby causes switches 71 and 72 to be closed to operate the motor 73 in a direction to lower the movable cabinet section 12. As the movable cabinet section 12 approaches its lowermost position, it contacts the horizontal extension 62 of contact bar 58 and forces it downwardly to depress leaf spring 57 and release stop member 29 from latch 53. The stop member 29 is then forced downwardly by coil spring and depresses switchoperating member 19. The downward movement of stop member 29 pivots trip members 39 and to raise

start members

24 and 25 and the depression of switch-operating member 19 raises switch-operating member 18. Thus switches 71 and 72 are opened and motor 73 and movable cabinet section 12 are stopped.

Regardless of the direction in which the movable cabinet section is moving the operator may stop the movable cabinet section by pressing downwardly on either of

extensions

63 and 64. This action depresses control bar 58 and releases stop member 29 for downward movement by action of coil spring 35 to stop the movable section. Additionally, if a foreign object, such as the operators hand or the handle of a kitchen utensil, has been inserted into the movable cabinet section while it is in its raised position and is not removed prior to lowering of the movable section, the pressure exerted on the control bar at any point along the length of the cabinet, when the movable section comes into contact with the foreign object and forces it against the control bar, operates to depress leaf spring 57 and plunger 56 to release stop member 29 and stop movement or" the movable section. The parallel arm connection between control bar 58 and control bar support member 59 assures that the pressure necessary to release the stop member is uniform over the entire length of the control bar and is only the pressure which is necessary to depress leaf spring 57. Thus the movable cabinet section will automatically stop prior to the time that any damage is done to a foreign object caught between the two cabinet sections.

Other modifications of this invention will occur to those skilled in the art and it is to be understood, therefore, that this invention is not limited to the particular embodiment disclosed but that it is intended to cover all modifications which are within the true spirit and scope of this invention as claimed.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. For use with a power-operated device, a combination control and safety mechanism to operate a control switch for the device comprising:

(a) a manually-operated first member to close the switch to start the device,

(1)) a second member to open the switch to stop the device when said second member is in a first position,

(0) biasing means to bias said second member to said first position,

(d) means interconnecting said first member and said second member so that movement of said first memher to close the switch causes said second member to move to a second position and comprising:

(aa) a trip member pivoted intermediate its ends,

(bb) one end of said trip member being engageable by said first member, and

( ce) the other end of said trip member being engageable by said second member,

(dd) whereby movement of said first member to close the switch effects pivoting movement of said trip member to move said second member to said second position and movement of said second member to said first position resets said first member,

(e) a latch engaging said second member to secure said second member in said second position, and

(f) a pressure'responsive release mechanism to disengage said latch from said second member,

(g) said biasing means being effective, upon disengagement of said latch from said second member, to move said second member to said first position to open the switch and stop the device.

2. For use with a power-operated device, a combination control and safety mechanism to operate a control switch for the device comprising:

(a) a manually-operated first member to close the switch to start the device,

(c) biasing means to bias said second member to said first position,

(d) means interconnecting said first member and said second member so that movement of said first member to close the switch causes said second member to move to a second position,

(.2) a latch engaging said second member to secure said second member in said second position, and

(f) a pressure-responsive release mechanism to disengage said latch from said second member and comprising:

(aa) an elongated control bar support member attached to the device,

(bb) an elongated, movable control bar, and

(cc) a plurality of spaced, parallel arms pivotally secured to said control bar and to said support member for rnovably mounting said control bar on said support member,

(dd) whereby said control bar remains parallel to said support member during movement of said control bar so that the pressure necessary to disengage said latch from said second member is substantially the same over the entire length length of said control bar,

3. For use with a power-operated cabinet including a stationary section and a vertically movable section mounted for movement with respect to the stationary section, a combination control and safety mechanism to operate a control switch for the cabinet, comprising:

(a) a first start member to close the switch to cause the movable section to move upwardly,

(b) a second start member to close the switch to cause the movable section to move downwardly,

(c) a stop member to open the switch to stop movement of the movable section when said stop member is in a first position,

(d) biasing means to bias said stop member to said first position,

(e) means interconnecting said first start member and said stop member so that movement of said first start member to close the switch causes said stop member to move to a second position,

(1) means interconnecting said second start member and said stop member so that movement of said second start member to close the switch causes said stop member to move to said second position,

(g) a latch engaging said stop member to secure said stop member in said second position, and

(h) a pressure-responsive release mechanism to disengage said latch from said stop member and comprising:

(aa) an elongated control bar support member attached to the cabinet and extending substantially the entire length of the cabinet,

(12b) an elongated, movable control bar extending substantially the entire length of the cabinet, and

(cc) a plurality of spaced, parallel arms pivotally secured to said control bar and to said support member for movably mounting said control bar on said support member,

(dd) whereby said control bar remains parallel to said support member during movement of said control bar so that the pressure necessary to disengage said latch from said second member is substantially the same over the entire length r of said control bar,

(i) said biasing means being effective, upon disengagement of said latch from said stop member, to move said stop member to said first position to open the switch and stop movable section.

4. A control and safety mechanism as described in claim 2 wherein said release mechanism also includes a plunger biased away from said latch and movable by said control bar to contact said latch and disengage said latch from said second member when pressure is exerted upon said control bar.

5. A control and safety mechanism as described in claim 3 wherein said release mechanism also includes:

(a) a stop arm pivotally mounted on said support member and having one end engaging said control bar and further having the other end projecting from said support member into the path of the movable section of the cabinet so that the movable section engages the stop arm as the movable section approaches its extreme upper position for exerting pressure on said control bar to open the switch, and

(b) wherein said control bar is positioned in the path of the movable section so that the movable section engages the control bar as the movable section aptil 8 proaches its extreme lower position for exerting pressure on the control bar to open the switch.

6. For use with a power-operated cabinet including a stationary section and a vertically movable section mounted for movement with respect to the stationary section, a combination control and safety mechanism to operate a control switch for the cabinet, comprising:

(b) a second start member to close the switch to cause the movable section to move downwardly, (c) a stop member to open the switch to stop movement of the movable section when said stop member is in a first position,

(d) a coil spring biasing said stop member to said first position,

(e) means for compressing said coil springs upon movement of said stop member to a second position to store energy for moving said stop member to said first position,

(f) a first trip member pivoted intermediate its ends,

(g) the first end of said first trip member being engageable by said first start lever and the second end of said first trip member engaging said stop member so that movement of said first start member to close the switch causes said stop member to move to said second position,

(It) a second trip member pivoted intermediate its ends,

(i) the first end of said second trip member being engageable by said second start member and the second end of said trip member engaging said stop member so that movement of said second start member to close the switch causes said stop member to move to said second position,

(j) a latch engaging said stop member to secure said stop member in said second position, and

(k) a pressure-responsive release mechanism to disengage said latch from said stop member and including,

(an) an elongated control bar support member attached to the stationary section of the cabinet and extending substantially the entire length of the cabinet,

(bb) an elongated, movable control bar extending substantially the entire length of the cabinet,

(cc) a plunger biased away from said latch and movable by said control bar to contact said latch and disengage said latch from said stop member when pressure is exerted on said control bar, (dd) a plurality of spaced, parallel arms pivotally secured to said control bar and to said support member whereby said control bar remains parallel to said support member during movement of said control bar so that the pressure necessaryto move said plunger is substantially the same over the entire length of said control bar, and

(ee) a stop arm pivotally mounted on said support member,

(ff) one end of said stop arm engaging said control bar and the other end of said stop arm projecting from said support member into the path of the movable section of the cabinet so that the movable section engages said stop arm as the movable section approaches its extreme upper position for exerting pressure on said control bar to move said plunger into engagement with said latch to disengage said latch from said stop member,

(gg) said control bar being positioned in the path of the movable section so that the movable section engages said control bar as the movable section approaches its extreme lower position for exerting pressure on said control bar to move said plunger into engagement with said latch to disengage said latch from said stop member,

(I) said coil spring being effective, upon disengagement of said latch from said stop member, to move said stop member to said first position to open the switch and stop the movable section.

7. A combination control and safety mechanism as described in claim 6 wherein:

(a) said stop member has a slot therein,

(b) said second end of said first trip member includes a pin which is received in said slot in said stop member so that movement of said first start member to close the switch causes said stop member to move-to said second position, and

(c) said second end of said second trip member includes a pin which is received in said slot in said stop member so that movement of said second start member to close the switch causes said stop member to move to said second position.

8. A power-operated cabinet structure comprising:

(a) a stationary cabinet section including an upstanding ledge having an opening therein,

(b) a movable cabinet section mounted adjacent said stationary section and overlying said upstanding ledge,

(c) a switch to control movement of said movable section,

(d) a combination control and safety mechanism mounted in said opening in said ledge to operate said switch comprising:

(aa) a first start member to close said switch to cause said movable section to move upwardly,

(bb) a second start member to close said switch to cause the movable section to move downwardly,

(cc) a stop member to open said switch to stop movement of the movable section when said stop member is in a first position,

(dd) biasing means to bias said stop member to said first position,

(ee) means interconnecting said first start member and said stop member so that movement of said first start member to close said switch causes said stop member to move to a second position,

(7?) means interconnecting said second start member and said stop member so that movement of said second start member to close said switch causes said stop member to move to said second position, and

(gg) a latch engaging said stop member to releasably secure said stop member in said second position,

(hh) said biasing means being effective, upon disengagement of said latch from said stop member to move said stop member to said first position to open said switch and stop said movable section, and

(e) a pressure-responsive release mechanism for disengaging said latch from said stop member comprismg:

(an) an elongated control bar support member attached to said upstanding ledge and extending substantially the entire length of said cabinet,

(bb) an elongated control bar movably mounted on said support member,

(cc) said control bar having a portion disposed adjacent the upper surface of said ledge for contact by said movable section to automatically stop said movable section, and

(dd) said control bar including an extension projecting outwardly from said movable section adjacent said control and safety mechanism whereby the operator may depress said control bar to stop said movable section without reaching under said movable section.

9. A power-operated cabinet including:

(a) a stationary cabinet section,

(b) a movable cabinet section mounted for movement with respect to said stationary section,

(0) a switch to control the movement of said movable section,

(d) a first start member to close said switch to cause said movable section to move upwardly,

(e) a second start member to close said switch to cause said movable section to move downwardly, (f) a stop member to open said switch to stop movement of said movable section when said stop member is in a first position,

(g) a coil spring biasing said stop member to said first position,

(11) means to compress said coil spring upon movement of said stop member to a second position to store energy for moving said stop member to said first position,

(i) said stop member having a slot therein,

(j) a first trip member pivoted intermediate its ends,

(k) one end of said first trip member being engageable by said first start member and the other end of said first trip member including a pin received in said slot in said stop member so that movement of said first start member to close said switch causes said stop member to move said second position,

(I) a second trip member pivoted intermediate its ends,

(in) one end of said second trip arm being engageable by said second start member and the other end of said second trip member including a pin received in said slot in said stop member so that movement of said second start member to close said switch causes said stop member to move to said second position,

(it) a latch engaging said stop member to secure said stop member in said second position, and

(0) a pressure-responsive release mechanism to disengage said latch from said stop member, comprismg:

(aa) an elongated control bar support member attached to said stationary cabinet section and extending substantially the entire length of said cabinet,

(bb) an elongated, movable control bar extending substantially the entire length of said cabinet,

(cc) a plunger biased away from said latch and movable by said control bar to contact said latch and disengage said latch from said stop member,

(dd) a plurality of spaced, parallel arms pivotally secured to said control bar and to said support member whereby said control bar remains parallel to said support member during movement of said control bar so that the pressure necessary to move said plunger is substantially the same over the entire length of said control bar, and

(ee) a stop arm pivotally mounted on said support member,

(ff) one end of said stop arm engaging said control bar and the other end or said stop arm projecting from said support member into the path of said movable cabinet section so that said movable cabinet section engages said stop arm as said movable cabinet section approaches its extreme upper position to exert pressure on said control bar to move said plunger into engagement with said latch to disengage said latch from said stop member,

(gg) said control bar being positioned in the path of said movable section so that said movable 1 1 12 section engages said control bar as said mov- References Cited by the Examiner able section approaches its extreme lower posi- UNITED STATES PATENTS tion to exert pressure on said control bar to remove said plunger into engagement with said 24291523 10/47 Murphy 312 312 X latch to disengage said latch from said stop 54 2825616 3/58 9 312 223 Ember, if)??? 523 d "5 3, 3. X

s 'd co'l s rin b ff ctive, u d en a e- 2 W00 War 23 X (P) m 1 p g mg 6 6 18 g g 3,116,910 1/64 Moore et nl 254-126 ment of said latch from said stop member, to move said stop member to said first position to open said FRANK SHERRY, 'Y Examine!- switch and stop said movable section of said cabinet. 10' CHANCELLOR E, HARRIS, Examiner.

Claims

1. FOR USE WITH A POWER-OPERATED DEVICE, A COMBINATION CONTROL AND SAFETY MECHANISM TO OPERATE A CONTROL SWITCH FOR THE DEVICE COMPRISING: (A) A MANUALLY-OPERATED FIRST MEMBER TO CLOSE THE SWITCH TO START THE DEVICE, (B) A SECOND MEMBER TO OPEN THE SWITCH TO STOP THE DEVICE WHEN SAID SECOND MEMBER IS IN A FIRST POSITION, (C) BIASING MEANS TO BIAS SAID SECOND MEMBER TO SAID FIRST POSITION, (D) MEANS INTERCONNECTING SAID FIRST MEMBER AND SAID SECOND MEMBER TO THAT MOVEMENT OF SAID FIRST MEMBER TO CLOSE THE SWITCH CAUSES SAID SECOND MEMBER TO MOVE TO A SECOND POSITION AND COMPRISING: (AA) A TRIP MEMBER PIVOTED INTERMEDIATE ITS ENDS, (BB) ONE END OF SAID TRIP MEMBER BEING ENGAGEABLE BY SAID FIRST MEMBER, AND (CC) THE OTHER END OF SAID TRIP MEMBER BEING ENGAGEABLE BY SAID SECOND MEMBER, (DD) WHEREBY MOVEMENT OF SAID FIRST MEMBER TO