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Publication numberUS3814874 A
Publication typeGrant
Publication dateJun 4, 1974
Filing dateMar 30, 1973
Priority dateMar 30, 1973
Also published asCA1001700A1, DE2415375A1
Publication numberUS 3814874 A, US 3814874A, US-A-3814874, US3814874 A, US3814874A
InventorsBrown W
Original AssigneeMallory & Co Inc P R
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Cam-actuated timer switch
US 3814874 A
Abstract
A cam-actuated timer switch, substantially thin in profile, utilizes two cam members rotating side-by-side and two sets of contact-carrying blades, each set being located on either side of a line through the centers of the two cam members.
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Description  (OCR text may contain errors)

United States Patent 191 Brown 1 June 4, 1974 [5 CAM-ACTUATED TIMER SWITCH 3,319,198 5/1967 Thomas 2011/27 R x 3.478,!81 11/1969 Buckerrid 6 et a1 ZOO/38 B [75] Inventor! g Brown, Beech Grove 3,727,015 4/1973 Voland et al. ZOO/38 R n [73]- Assignee: P. R. Mallory & Co. Inc.,

Indianapolis, Ind. Primary Examiner-James R. Scott Attorney, Agent, or Firm-Richard H. C hildress; [22] Charles W. Hoffmann; Robert'F. Meyer [21] Appl. No.: 346,313. 52 US. Cl 2110/38 B, 200/27 B. 200/30 R, v r l 7 200/153 LB 1571 ABSTRACT [51] Int. Cl. H0111 43/10 1 1 I [58] Field of Search 200/27 R, 27 B, 30 R, 30A, A Cam-actuated timer switch, substantially thin in pro- 200/31 R, 31 A 38 R, 38 B, 38 BA, 38 C, 38 file, utilizes two cam members rotating side-by-side CA, 153 L, 153 LA 153 LB and two sets of contact-carrying blades, each set being I 1 located on either side of a. line through the centers of [56] References Cited the two 'cam members- 1 UNITED STATES PATENTS 7 2,877.31? 3/1959 Euler et 11. 1. ZOO/38 C x 16 Claims, 7 Drawing Figures CAM-ACTUATED TIMER SWITCH Generally speaking, the present invention relates to a cam-acutated timer switch including two cam members rotating side by side in an enclosure and a long and short set of contact-carrying blades responsive to the cam members wherein the long set is located on one side of a line through the centers of the cam members and the short set is located on the other side of that line. Another embodiment of the present invention relates to a cam-actuated timer switch including a cam member rotating in a substantially-thin enclosure wherein the enclosure includes two groups of slots and a set of contact-carrying blades responsive to the cam member and disposed in one of the groups of slots.

The trend to make domestic and industrial appliances smaller and more compact has created a demand for thin timer switches and controls for use in these appliances. The present timer switch, being substantially thin in cross-section adapts well to such limited-space applications. For example, the present timer switch may be used in a kitchen blender to provide a preselected amount of on time. In this example, the timer may be located in a small molded-plastic base in which larger timer switches would not fit.

One embodiment of the present invention utilizes two cam members rotating side by side instead of in the conventional in-line arrangement found in many timers. This side-by-side embodiment is thinner in a dimension taken parallel to the cam axes than an in-line version-employing the same number and size of cam members.

The structure of the present invention allows a variety of combinations of cam members and sets of contact-carrying blades. In an embodiment utilizing one cam member, a set of contact-carrying blades responsive to the cam member may be disposed in one of two groups of slots so that they may be responsive to either direction of rotation of the cam member. In addition, the cam member may be flipped over 180 to present the same cam profiles to the set of contact-carrying blades in their alternate location.

The versatility of the present invention is demonstrated again in the embodiment of the invention utilizing two cams rotating side by side. Each of a long and short set of contact-carrying blades is disposed in one of two groups of slots. The slots are located in the structure in such a way that the long and short sets of contact-carrying blades may be interchanged, whereby each set may be responsive to either of the two cam members. To achieve this versatile interchangeability of cam members and contact-carrying blades, the two sets of slots are disposed opposite sides of a line through the centers of the two cam members.

The present invention also includes provisions for a contact-spacing means separating two contact-carrying blades in each set a predetermined distance apart to achieve improved electrical switching characteristics in the form of more accurately controlled air gaps between the contacts.

Accordingly, a feature of the present invention is to provide a cam-actuated timer switch substantially thin in a direction substantially parallel to the axis of a timer motor output shaft. Another feature of the present invention is to provide a cam-actuated timer switch with a variety of available locations and combinations of cam members and contact-carrying blades. Another feature of the present invention is to provide a camactuated timer'switch with two cams one each rotating on parallel shafts and in opposite directions. Another feature of the present invention is to provide a camactuated timer switch including an enclosure that substantially envelops the cam members and contactcarrying blades and provides support, location and entrapment of the contact-carrying blades. Still another feature of the invention is to provide a cam-actuated timer switch with a contact separation means separating two contact-carrying blades a predetermined distance apart to achieve improved electrical switching characteristics. Yet another feature of the present invention is to provide a cam-actuated timer switch that is neat and compact in size. Another feature of the present invention is to provide a cam-actuated timer switch that is simple and economical to produce.

These and other features of the invention will become apparent from the following description taken in conjunction with the accompanying drawing wherein:

FIG. 1 is an elevation view of an embodiment of the invention.

FIG. 2 is a front view of an embodiment of the invention, with the motor shown in FIG. I removed, utilizing a primary cam and a set of contact-carrying blades.

FIG. 3 is a front view of the same embodiment as shown in FIG. 2 with the cam flipped over and the contact-carrying blades in an alternate location.

FIG. 4 is a front view of an embodiment of the invention, with the motor shown in FIG. I removed, utilizing two cams and two sets of contact-carrying blades.

FIG. 5 is a front view of the same embodiment shown in FIG. 4 with the cams flipped over and the sets of contact-carrying blades interchanged.

FIG. 6 is a rear view ofa slider engaging a set of contact-carrying blades.

FIG. 7 is a section taken along the line 7-7 of FIG. 4.

Referring now to the drawing, a synchronous gear motor 10 and a substantially-thin timing means 20 are connected together by an attachment means 13. Synchronous gear motor 10 includes a gear housing 11. Attachment means 13 comprises a plurality of hollow rivets l6-inserted through holes in the gear housing 11 and substantially thin timing means 20 and headed over, thereby securing the two together.

' In the embodiment shown in FIGS. 2 and 3, cam means 26 includes a primary cam member 32 comprising two cam tracks 34 and 36. Primary cam member 32 is carried on an output shaft 38 extending from motor 10.

In the embodiment shown in FIGS. 4, 5, and 7, cam means 27 includes a primary cam member 40 comprising two cam tracks 42 and 44 and a cam separation means 46-. Cam separation means 46 comprises a gear 48 sandwiched in between the two cam tracks 42 and 44. Cam means 27 further includes a secondary cam member 50 comprising two cam tracks 52 and 54 and a cam separation means 56. Secondary cam member 50 is carried on a second shaft 49 which is rotatably journaled in a cup-shaped housing 58. Cam separation means 56 comprises a gear 57 sandwiched in between the two cam tracks 52 and-54. A coupling means 51 coupling the two cam members together comprises gear 48 in engagement with gear 57.

In both embodiments, an enclosure 30 is of a substantially parallelpiped' shape and comprises cup-shaped housing 58 and a substantially thin and flat cover 60. Enclosure 30 includes aratio of thickness-to-perimeter distance of from 1/40 to 1/20 wherein the thickness is taken in a direction substantially parallel to the longitudinal axis of output shaft 38, and the perimeter is measured around enclosure 30 in a plane substantially perpendicular to the longitudinal axis of the output shaft 38. The cup-shaped housing 58 includes a first set of slots 62 disposed in a wall 59 of the cup-shaped housing as shown in FIG. 2. A second set of slots 64 is shown disposed in an alternate location in wall 59 in FIG. 3. Each set of slots 62 and 64 contains a plurality of slots, and each set is located on opposite sides of a line A-B through the centers of primary cam member 40 and secondary cam member. 50. Both sets of slots 62 and 64 are shown in the embodiment illustrated in FIGS. 4 and Electrical switching means 28 includes a plurality of contact-carrying blades 66 and 68 which are inserted in one of the sets of slots 62 and 64 shown in the em bodiment illustrated in FIGS. 2 and 3. Cam follower tips 67 and 69 are disposed on the distal ends of blades 66 and 68 respectively. Electrical contacts 63 appear on blades 66 and 68 also. Substantially-thin and flat cover 60 of second enclosure 30 entraps the plurality of contact-carrying blades 66 and 68 in one of the sets of slots 62 and 64.

Electrical switching means 29 includes a long set 70 v and a short set 72 of contact-carrying blades, each set being inserted in one of the sets of slots 62 and 64 in the embodiment shown in FIGS. 4 and 5. The long set 70 is responsive to primary cam member 40, and the short set 72 is responsive to secondary cam member 50. Cam follower tips 74 and 76 are disposed on the distal ends of two of the long set of contact-carrying blades 70, and cam follower tips 78 and 80 are disposed on the distal ends of two of the short set of contact-carrying blades 72. A first set of contacts 71 is carried by the long set of contact-carryin g blades 70, and a second set of contacts 73 is carried by the short set of contactcarrying blades 72. Substantially thin and flat cover 60 of enclosure 30 entraps the long set and short set of contact-carrying blades 70 and 72 in the sets of slots 62 and 64.

In the embodiment shown in FIGS. 4 and 5, the long set of contact-carrying blades 70 is located on one side ofa line A-B through the centers of primary cam member 40 and secondary cam member 50, and the short act of contact-carrying blades 72 is located on the other side of line A-B.

A contact-spacing'means 82 comprises a slider 84 freely translatable along one of a plurality of slider guides 86 which are disposed on the inside of cupshaped housing 58. Slider 84 includes lugs 88 and 90 which engage the long set of contact-carrying blades 70. Slider 92 includes lugs 94 and 96 which engage the short set of contact-carrying blades 72. The long and short sets of contact-carrying blades 70 and 72 restrain sliders 84 and 92 each in contact with a slider guide 86.

In operation, synchronous gear motor causes output shaft 38 and primary cam member 40, carried on the output shaft, to rotate.

In the embodiment of the invention shown in FIGS. 2 and 3, cam means 26 comprises a primary cam member 32. As primary cam member 32 rotates past cam follower tips 68 and 66 respectively, contacts 63 make and break according to profiles on cam tracks 34 and 36.

In the embodiment of the invention shown in FIGS. 4 and 5, the cam means 27 comprises a primary cam member 40 and a secondary cam member 50. As primary cam member 40 rotates past cam follower tips 74 and 76, the long set of contact-carrying blades respond to the profiles of cam tracks 42 and 44 causing electrical contacts 71 to open and close.

Gear 48 drives gear 57 on secondary earn member 50. This causes cam tracks 52 and 54 to rotate past the cam follower tips 78 and 80. The short set of contactcarrying blades 72 respond to the profiles of cam tracks 52 and 54 causing electrical contacts 73 to open and close.

Lugs 88 and on slider 84 engage two of the long set of contact-carrying blades 70 to partially sapce contacts 71 apart during their opening and closing. Lugs 94 and 96 on slider 92 engage two of the short set of contact-carrying blades 72 to partially space contacts 73 apart during their opening and closing.

What is claimed is:

l. A cam-actuated timer switch comprising:

a. a synchronous motor including an output shaft;

b. a cam means including a primary and a secondary cam member, wherein said primary cam member is carried on said output shaft and said secondary cam member is carried on a second shaft substantially parallel to said output shaft;

b. means connecting said secondary cam member to said primary cam member;

c. an electrical switching means responsive to said cam means including a long and short set of contact-carrying blades wherein said long set of contact-carrying blades is located on one side of a line through the centers of said primary and secondary cam members, and said short set of contactcarrying blades is located on the other side of said line;

d. an enclosure substantially enveloping said cam means and said switching means; and

e. an attachment means connecting said motor to said enclosure.

2. The cam-actuated timer switch according to claim 1 wherein said primary and secondary cam members each include a gear and two cam tracks separated by a cam separation means.

3. The cam-actuated timer switch according to claim 2 wherein said cam separation means comprises said gear.

4. The cam-actuated timer switch according to claim 2 wherein said means connecting said primary cam member to said secondary cam member comprises said gears on said primary and secondary cam members.

5. The cam-actuated timer switch according to claim 1 wherein said short set of contact-carrying blades is responsive to said secondary cam member and said long set of contact-carrying blades is responsive to said primary cam member.

6. The cam-actuated timer switch according to claim 1 wherein said enclosure comprises a cup-shaped housing and a substantially thin and flat cover.

7. The cam-actuated timer switch according to claim 6 wherein said cup-shaped housing includes a plurality of slots disposed in a side wall thereof in which are disv posed said long and short sets of contact-carrying blades.

8. The cam-actuated timer switch according to claim 7 wherein said substantially thin and flat cover entraps said long and short sets of contact-carrying blades in said slots.

9. The cam-actuated timer switch according to claim 1 wherein said long and short sets of contact-carrying blades are maintained in spaced relation to each other by a contact spacing means. 7

10. The cam-actuated timer switch according to claim 9 wherein said contact spacing means includes at least one slider freely translatable along one of a plurality of slider guides.

11. The cam-acutated timer switch according to claim 10 wherein one of said long and short sets of contact-carrying blades restrain said slider in contact with one of said slider guides.

12. The cam-actuated timer switch according to claim 1 wherein said enclosure enveloping said cam means and said switching means is substantially thin in a direction substantially parallel to said output shaft.

13. The cam-actuated timer switch according to claim 1 wherein said enclosure includes a ratio of thickness to perimeter. distance of from 1/40 to l/20, said thickness taken in a direction substantially parallel to a longitudinal axis of said output shaft, and said perimeter measured around the outside of said enclosure in a plane substantially perpendicular to the longitudinal axis of said output shaft.

14. A cam-actuated timer switch comprising:

a. a synchronous motor including an output shaft;

b. a cam member, including two substantially concentric tracks, carried on said output shaft;

c. a plurality of contact-carrying blades responsive to said cam tracks;

d. an enclosure substantially enveloping said cam member and carrying said output shaft and enveloping and carrying said plurality of contactcarrying blades and wherein said enclosure-is substantially parallelpiped in shape including a ratio of thickness to perimeter distance of from l/40 to l/20, said thickness taken in a direction substantially parallel to a longitudinal axis of said output shaft, and said perimeter measures around the outside of said enclosure in a plane substantially perpendicular to said longitudinal axis of said output shaft;

e. an attachment means connecting said motor to said enclosure.

15. A cam-actuated timer switch comprising:'

a. a synchronous motor including an output shaft;

b. a cam means including a primary cam carried by said output shaft and having two cam tracks separated by a gear, a secondary cam member carried on a second shaft disposed substantially parallel to said output shaft and having two cam tracks separated by a gear, said gears engaging one another.

c. an electrical switching means responsive to said cam means including a long and short set of contact-carrying blades wherein said long set of contact-carrying blades is located on one side of a line through the centers of said primary and secondary cam members, and said short set of contactcarrying blades is located on the other side of said line;

d. an enclosure substantially enveloping said cam and electrical switching means comprising a cupshaped housing and a substantially thin flat cover closing same, said cup-shaped housing having a plurality of slots disposed in a side wall thereof in which are disposed said long and short contact carrying blades; and

e. an attachment means connecting saidmotor to said enclosure.

16. A cam-actuated timer switch comprising:

a. a synchronous motor including an output shaft;

b. a cam means including a primary cam carried by said output shaft and having two cam tracks separated by a gear, a secondary cam member carried on a second shaft disposed substantially parallel to said output shaft and having two cam tracks separated by a gear, said gears engaging one another.

c. an electrical switching means reponsive to said cam means including a long and short set of contact-carrying blades wherein said long set of contact-carrying blades is located on one side of a line through the centers of said primary and secondary cam members, and said short set of contactcarrying blades is located on the other side of said line, both said long and short set maintained in spaced relation to each other by a contact spacing means;

d. an enclosure substantially enveloping said cam means and said switching means; and

e. an attachment means connecting said motor to said enclosure.

I mT ED STATES PATENT OFFICE 7 CERTIFICATE OF CORRECTION Patent No. 3, 814 8 74. Dated 06/0 4/74 Inventor(s) William Brown It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, line 66 after cam delete"members" ano.

insert-"Itieans"-'.,

Signed andsesled this 19th day of November 19%.

(SEAL) Attest McCOY M. GIBSON JR. 7 c. MARSHALL DANN v Attesting Officer Conunissioner of' Patents F QRM PO-105O (10-69) USCOMM-DC eoavm a v UTS. GOVERNMENT PRINTING OFFICE I989 O-SSi-S,

Q memo STATES PATENT OFFICE QERTIFICATE OF CORRECTION Dated Patent No 3, 814 874 IHVGIHZOT S William Brown It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 2, line 66 after cam delete"members" anfi insert-"means,

Signed and sealed this 19th day of November 1974.

(SEAL) Attest McCOY M. GIBSON JR. 6. MARSHALL DANN Attesting Officer Commissioner of' Patents USCOMM-DC 50376P59 9 ".5. GOVERNMENT PRINTING OFFICE l9, O-aii-SM,

FORM PO-l 050 (10-65)

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2877317 *Feb 5, 1957Mar 10, 1959Gen ElectricSwitching mechanism for timer
US3319198 *Jun 21, 1965May 9, 1967Johnson Matthey & Mallory LtdMiniature telephone interrupter switch
US3478181 *Mar 1, 1967Nov 11, 1969Jones Alan VictorElectric circuit controllers incorporating time-switches
US3727015 *Apr 12, 1971Aug 18, 1987 Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4130746 *Apr 11, 1977Dec 19, 1978Whirlpool CorporationSnap-action cam for timer switch
US4297547 *May 5, 1980Oct 27, 1981Emhart Industries, Inc.Miniature timing mechanism
US4381432 *Jun 1, 1981Apr 26, 1983General Electric CompanyElectromechanical timer with improved short interval accuracy
US4493955 *Apr 18, 1983Jan 15, 1985Colman Oem, Inc.Control mechanism for an electric motor assembly
US4525608 *Dec 3, 1982Jun 25, 1985General Electric CompanyTimer mechanism with improved interval accuracy
US5834718 *Mar 3, 1997Nov 10, 1998Emerson Electric Co.Appliance timer having a switching mechanism for high-current carrying circuit blades and associated method
Classifications
U.S. Classification200/38.00B, 200/501, 200/19.2, 200/19.15
International ClassificationH01H19/62, H01H43/10, H01H43/00, H01H19/00
Cooperative ClassificationH01H19/62, H01H43/103, H01H43/10
European ClassificationH01H19/62, H01H43/10, H01H43/10B
Legal Events
DateCodeEventDescription
May 6, 1991ASAssignment
Owner name: EMERSON ELECTRIC CO. A CORP. OF MISSOURI, MISSO
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:EMHART INDUSTRIES, INC. A CORP. OF CONNECTICUT;REEL/FRAME:005691/0720
Effective date: 19910125