US2837933A - Double detent mechanism - Google Patents

Description

June w, 1958 L. J. PATLA DOUBLE DETENT MECHANISM Filed Aug. 12, 1955 INVENTOR.

para. BY-

MN .v W

Unite 2,837,933 Patented June 10, 1958 DUUBLE DETENT MECHANISM Louis J. Patla, Elmwood Park, Ill.

Application August 12, 1953, Serial No. 373,843

6 Claims. (Cl. 74-627) This invention relates to a double detent mechanism and to a television tuner switch employing such a double detent mechanism. it is an object of the invention to provide improved apparatus of that character.

In view of the prospective use of additional television channels, some in the ultra high frequency range, it is desirable that the basic tuning switch of television sets have more than the customary twelve positions or settings, preferably twice that number. Normally, some form of detent mechanism is employed whereby the movable switch element snaps successively into these positions or settings as the operator turns the switch to tune the television set to different channels. However, a simple detent mechanism having twenty-four positions must necessarily be objectionably large in diameter. For example, in a ball type detent mechanism, if the ball and the various detents are to be of substantial size, in order to give smooth and positive action, they must be substantially removed from the axis of the rotary switch parts in order to obtain a large circle of travel. Such a large detent mechanism is objectionable in television sets because of the already cramped quarters.

According to one embodiment of the present invention, only twelve positions are provided in the basic detent mechanism and a second detent mechanism is provided by which the relatively stationary plate of the first detent mechanism may be pivoted through an angle which is equal to one and one-half times the angle between the various positions provided for by the first detent mechanism. lt will readily be seen that if the first or basic detent mechanism provides for movement of the movable switch element to various positions separated by 30, movement of the relatively stationary plate of the detent mechanism through an angle of 45 will permit movement of the switch element to a series of positions lying intermediate the adjacent switch positions obtainable prior to shifting of the said detent plate. Through this means, twenty-four positions of the switch arm become available while using a basicdetent mechanism which provides for movement of the switch arm through steps of 30.

A detent mechanism constructed in accordance with the invention permits the selection of any one of a large number of switch positions even though both elements of the detent mechanism are small in diameter whereby the basic or principal detent mechanism, which is old in .the art, permits the selection or" only a small number of switch positions.

Accordingly, it is another object of the invention to provide an improved detent mechanism which is small in size and, particularly, small in diameter and which still permits smooth, positive positioning of a controlled device in any one of a large number of positions.

Where a double detent mechanism constructed in accordance with the invention is applied to a television tuning switch, for example, the positions of the switch as controlled by the primary or basic detent mechanism, with the second detent mechanism in one given position,

may be positions corresponding to the V. H. F. channels,

'2,721,'9 11, both by the present inventor. construction of the tuning switch proper does not of itwhile another set of switch positions permitted by the primary detent mechanism when the secondary detent mechanism is in a second position, may be positions corre sponding toU. H. F. channels. A suitable index on the second detent mechanism may indicate V. H. F. and U. H. F. in its respective positions, whereby the selection and indication of V. H. F. and U. H. F. channels is simplilied and clarified Accordingly, it is another object of the invention to provide an improved tuning switch assembly for a television set.

It is another object of the invention to provide improved double detent mechanism which may select two or more times the number of positions for the controlled element as any previously known detent mechanism of the same diameter. it is another object of the invention to provide an improved television tuner switch incorporat ing such a double dctent mechanism therein.

This invention, together with further objects and advantages thereof, will best be understood by reference to .the following description taken in connection with the accompanying drawing, in the appended claims.

In the drawing, in which like parts are designated by likereference numerals,

Fig. 1 is an exploded perspective View of television set tuning switch apparatus illustrating one embodiment of the invention;

Fig. 2 is an elevational view of the rotary switch element incorporated in the tuning switch of Fig. 1; and

'Fig. 3 is a diagram illustrating the various selectable positions of the tuning switch madepossible by the double detentmechanism incorporated in the tuning switch assembly of Fig. l.

The television tuning switch assembly illustrated in Fig. 1 includes at the right-hand end a tuning switch proper ill. This switch includes a substantially cupshaped base '22 secured to rods 13 which form a part of the frame of the assembly. Stationary contact supports 14 are mounted on the back of the cup-shaped member 12, these supports extending through an opening 15 in the cup-shaped member 12 to support stationary contacts in desired positions within the cup-shaped member.

Also arranged within the cup-shaped member 12 is a rotary switch member 16, see Fig. 2, lating plate 17 upon which are mounted a series of contacts 18 and a series of tuning coils 19, see Fig. 1. It will and its scope will be pointed out be noted that the insulating plate 3.7 is slotted at its center ;placed in the tuning circuits to tune the television set to different channels. Preferably, two coils or center tapped coils are arranged on each of twelve coil bases to permit greater concentration of the necessary tuning coil construction. The tuning switch proper may be, and prefer- ,ably is, constructed in accordance with the inventions disclosed and claimed in application Serial No. 139,229, entitled Multiple Contact Switch,'filed January 18, 1950,

now Patent No. 2,682,645, and application Serial No.

189,458, entitled Electrical Apparatus and Method of Making Same, filed October 10, 1950, now Patent No. Since the actual self-constitute a feature of the present invention, and since a suitable switch mechanism is described in the aboveidentified applications, it will not be described in further detail herein.

To the left of the tuning switch 11 there is a primary comprising an insudetent mechanism 21. This includes a ball plate 22 ,Which is slotted to receive the operating shaft 20. Two

detent balls 23 cooperate with the ball plate 22 and are caused to rotate therewith, upon turning of the operating shaft, through their engagement with respective holes 24 in the plate 22. The holes 24 are substantially smaller than the balls 23, whereby the balls cannot pass through the holes but are retained in a fixed position with respect to the plate 22.

A detent plate 25 is provided having a series of protrusions 26 which define intermediate depressions 27. It will be seen that the alternate protrusions 26 and depressions 27 are arranged in a circle of such diameter that as the ball plate 22 is caused to rotate with respect to the detent plate 25, the balls 23 must ride over the protrusions 26 and snap successively into the intermediate depressions. If it be assumed that the detent plate 25 is held stationary, it will be seen that the ball plate 22 tends strongly to snap into various definite angular positions with respect to the detent plate 25. Similarly, the shaft 20 and hence the rotary contact member 16 also tend to settle into predetermined angularly displaced positions.

A second detent mechanism 31 employs a ball plate 32 and balls 33, similar to the ball plate 22 and the balls 23, the ball plate 32 being provided with holes 34 which are smaller than the cooperating balls 33 but large enough to cause the balls 33 to rotate with the ball plate 32.

A detent plate 35 is provided which is secured to a portion of the frame of the over-all assembly. The detent plate 35 has arranged thereon pairs of protrusions 36 and intermediate protrusions 36' which define depressions 37. It will be understood that the balls 33 ride over the intermediate protrusions 36' and snap into depressions 37 at either side thereof. The protrusions 36 are of such height that the balls 33 cannot ride thereover, whereby in the illustrated embodiment of the invention the ball plate 32 may occupy either one of only two operating positions.

It will be seen that screws 38 are provided by which the ball plate 32 may be secured to the detent plate 25, the screws 38 passing through slots 32' in the ball plate 32 and into threaded openings 25' in the detent plate 25.

The ball plate 32 is securely mounted on an operating shaft 40 which is actually a tube surrounding an intermediate portion of the operating shaft 20. A suitable handle 41 is secured to the shaft 40 and a handle 42 is secured to the shaft 20.

The angular displacement of the pairs of depressions 37 in the detent mechanism 31 is made equal to 45 in the illustrated embodiment of the invention. The angular displacement of adjacent depressions 27 in the detent to snap successively into the angular positions designated by the indices a -a in Fig. 3.

If the control knob 41 is now rotated to cause the ball plate 32 of the detent mechanism 31 to snap into its alternate position, the ball plate 32, the entire detent mechanism 21, the shaft 20, and the rotary switch element 16 are all caused to rotate through an angle of 45 Accordingly, the same movable contact which might have been in the position a is moved to a position indicated by the index b Subsequent rotation of the control knob 42 will cause that same rotary contact to snap successively into the various positions indicated by the further indices b --b In the illustrated application of the double detent mechnism, namely, the application to a television set tuning switch, the switch 11 when in the positions corresponding to the indices a a might tune the set to V. H. F. channels, and the switch in the positions corresponding to the indices b b may tune the set to U. H. F. channels. In such case a suitable indicator mounted on the tubular shaft 40 or on the operating handle 41, not shown in the drawing, can be arranged to indicate V. H. F. and U. H. F. in the respective positions of the handle 41. Suitable indicia can be associated with handle 42 to indicate channels 1-12, and intermediate such indicia another set of indicia may be provided for indicating U. H. F. channels. If the handle 41 were then turned to its V. H. F. position, rotation of the handle 42 would result in successive indicating of channels 1-12, the corresponding indicia and the tuning switch skipping over the U. H. F. settings. Conversely, if the handle 41 were turned to its U. H. F. position, rotation of the handle 42 would result in the tuning switch 11 and the indicia associated with the tuning handle 42 assuming positions corresponding to the successive U. H. F. settings and skipping over the V. H. F. settings.

In the illustrated embodiment of the invention the secondary detent mechanism 31 has been arranged to snap through an angle of 45 rather than through an angle of 15, either of which would result in effectively shifting the movable switch contacts through 15. If the secondary detent mechanism 31 is in such position that the control handle 42 permits selection of any one of the positions corresponding to the indices el -r1 of Fig. 3, shifting of the secondary detent mechanism 31 through an angle of 15, 45 or 75 will permit the control handle 42 to move the same movable switch contacts only to positions corresponding to the indices b ---b of Fig. 3.

A 45 shift is preferable over a 15 shift in the detent mechanism 31, since the 45 shift permits larger and more definite protrusions 36 with correspondingly lighter spring pressure whereby the operation of this detent mechanism may be smoother and its centering action more positive. Obviously the forces which center the detent mechanism 31 in its positions must be superior to the forces operating in the primary detent mechanism 21 whereby rotation of the handle 42 in either direction will not cause operation of the detent mechanism 31.

The rotary switch member 16 of the illustrated embodiment has twenty-four pairs of contacts 18 u may be seen in Fig. 2. It will be noted that alternate pairs 18a of contacts are arranged on a pair of concentric circles and that the intermediate pairs 18b are arranged on different concentric circles. Two sets of stationary contacts (not shown) are arranged on the contact supports 14, one set so arranged as to engage the contacts 18a (and the other set arranged to engage the contacts 18b. The stationary contacts are spaced apart by an angle of 30, whereas the angle of displacement of adjacent pairs of movable contacts 18a and 18b is 15. Accordingly, when the handle 41 is in one position the movable contacts 18a may come to rest in engagement with cooperating stationary contacts while the contacts 18b come to rest in such positions that they do not contact the other set of stationary contacts. Conversely, when the handle 41 is in its other position, the contacts 18b cooperate successively with the other pair of stationary contacts while movable contacts 18a come to rest in positions wherein they do not electrically contact any stationary contacts.

In the illustrated embodiment of the invention, any given pair of contacts 18a may be connected to a V. H. F. tuning coil whereas an adjacent pair of movable contacts 18b is connected to a U. H. F. tuning coil which placed from each other by an angle of 40.

termediate the positions previously available.

disc 17and only twelve basic coil constructions .19 need be provided.

In the illustrated applicatijn of the detent mechanism or in other applications, it may be desired that the sec ondary detent mechanism 31 be provided with three or more angularly displaced positions. This can be accomplished by providing additional protrusions 36' and corresponding additional depressions 37. The angle of displacement in the prim-ary detent mechanism and in the secondary detent mechanism must of course be of such values as to result in different angular positions of the device-controlled by the overall detent mechanism. For example, if the primary detent mechanism is as suggested in the previously described embodiment of the invention, wherein it permits centering of the controlled device in twelve positions angularly displaced by 30, the three position secondary detent mechanism would opcrate satisfactorily it its adjacent positions were dis- Then when the secondary detent mechanism moves from its first position to its second position, the effective shifting of the controlled device would be 4030, or Move- .ment of the secondary detent mechanism to its third position, 80 from its original position, would result in an efiective shift of SSW-60, or The controlled device would then have three sets of twelve positions, the :twelve positions of any one set being selectable by operation of the primary detent mechanism, and the choice ofthe three sets of positions being selectable by operation of the secondary detent mechanism. An arrangement such as that suggested immediately above would be desirable in an application in which the three sets of positions of the controlled device had some distinguishing characteristic corresponding to the two V. H. F. and U. H. F. settings of the secondary detent mechanism 31 of the illustrated embodiment of the invention.

The illustrated embodiment of the invention employs two detent mechanisms in series with each other to the advantage that a primary detent mechanism may be of a given small size and may permit selection of any one of a given small number of angularly displaced positions of a controlled device. At the same time, the total number of positions of the controlled device is doubled or trebled by arranging a secondary detent mechanism in series with the primary detent mechanism, the secondary detent mechanism shifting the entire primary detent mechanism-as well as the controlled device through such an angle that the positions of the controlled device, now selectable by the primary detent mechanism, lie in- This invention therefore permits the'selection of any one of a large number of positions of a controlled device while employing a small, smoothly operating detent mechanism, which latter characteristics are inherent in a detent mechanism having a small number of selectable positions.

Furthermore, the present invention divides the total number of positions of the controlled device into groups, one group of positions being available by operation of one control handle when a secondary control handle is in one position, and the second group of positions being available by operation of the first control handle when the secondary handle is in another position. This characteristic of the invention is particularly desirable where the total number of positions of the controlled device may be divided into logical groups.

By way of example other than that illustrated in the drawing and described above, when the control handle 41 is in one position, operation of the control handle 42 may be caused to close successive circuits whereby temperature indications may be obtained, and with the control handle 41 in a second position, operation of the control handle 42 may be caused to close successive circuits whereby pressure indications may be obtained.

It is to be noted that the rotatable member of either U or both of the detent mechanisms may carry the protrusions 26 or 36 and inte mediate depressions defined thereby while the relatively stationary member may control the balls 23 or 33. Also various forms of detent mechanisms other than the illustrated ball type (many f which are known) may be used without departing from the spirit of the invention. Furthermore, the movable member 32 and the relatively stationary member 25 may be one integral element rather than two members secured together, and where two such members are specitie-d herein it is to be understood that such language is to be interpreted to include a single integral element serving two functions, one in connection with each of the two detent mechanisms.

Accordingly, while a particular embodiment of the invention has been shown, it will be understood, of course, that the invention is not limited thereto since many modifications may be made, and it is, therefore, contemplated to cover by the appended claims any such modifications as fall within the true spirit and scope of the invention.

The invention having thus been described, what is claimed and desired to be secured by Letters Patent is:

1. A detent mechanism comprising a relatively stationary base member and a rotatable member connected to a load element, said rotatable member and its load element being movable to center said load element in any one of a plurality of angularly displaced positions with respect to said base member, a second detent mechanism comprising a fixed member and a relatively rotatable member movable to any of at least two angularly displaced positions with respect to its fixed member, said base member or" the first detent mechanism being connected to and rotatable with said relatively rotatable member of the second detent mechanism, the angular displacement of said relatively rotatable member in moving between saidpositions being other than the angular displacement between positions of said load element, and said second detent mechanism being self-maintained in set position during operation of said first detent mechanism, whereby the positions of said load member due to rotation of its connected rotary member may be increased by movement of said relatively rotatable member from one position to another.

2. In a switch construction having a rotary switch element, a detent mechanism comprising a relatively stationary base member and a rotatable member connected to said switch element, said rotatable member and its switch element being movable to center said switch element in any one of a plurality of angularly displaced positions with respect to said base member, a second detent mechanism comprising a fixed member and a relatively rotatable member movable to any of at least two angularly displaced positions with respect to its fixed member, said base member of the first detent mechanism being connected to and rotatable with said relatively rotatable member of the second detent mechanism, the angular displacement of said relatively rotatable member in moving between said positions being other than the angular displacement between positions of said switch element, and said second detent mechanism being self-maintained in set position during operation of said first detent mechanism, whereby the positions of said switch element due to rotation of its connected rotary member may be increased by movement of said relatively rotatable member from one position to another.

3. A detent mechanism comprising a relatively stationary base member and a rotatable member connected to a load element, said rotatable member and its load element being movable to center said load element in any one of a plurality of positions angularly displaced with respect to said base member by a constant angle, a second detent mechanism comprising a fixed member and a relatively rotatable member movable to any of at least 12W? angularly displaced positions with respect to its fixed member, said base member, rotatable member, load element and relatively rotatable member being axially aligned, said base member of the first detent mechanism being connected to and rotatable with said relatively rotatable member of said second detent mechanism, the angular displacement of said relatively rotatable member in moving between said positions being other than the angular displacement between positions of said load element, and said second detent mechanism being self-maintained in set position during operation of said first detent mechanism, whereby the positions of said load member, due to rotation of its connected rotary member may be increased by movement of said relatively rotatable member from one position to another.

4. A detent mechanism comprising a relatively stationary base member and a rotatable member connected to a load element, said rotatable member and its load element being movable to center said load element in any one of a plurality of positions angularly displaced with respect to said base member by an angle X, a second detent mechanism comprising a fixed member and a relatively rotatable member movable to any of at least two angularly displaced positions with respect to its fixed member, said base member, rotatable member, load element and relatively rotatable member being axially aligned, said base member of the first detent mechanism being connected to and rotatable with said relatively rotatable member of said second detent mechanism, the angular displacement of said relatively rotatable member in moving between its said positions being equal to an odd, integral multiple of one-half X, and said second detent mechanism being self-maintained in set position during operation of said first detent mechanism, whereby the positions of said load member due to rotation of its connected rotary member may be increased by movement of said relatively rotatable member from one position to another.

5. In a double detent construction having a pair of concentric shafts'with the inner shaft projecting beyond one end of said outer shaft, 2. first detent mechanism comprising a relatively stationary base member mounted on said outer shaft and a rotatable member connected to a load element, both mounted on the exposed end of said inner shaft, said rotatable member and its load element being movable upon rotation of said inner shaft to center said load element in any one of a plurality of angular displaced positions with respect to said base member, a second detent mechanism comprising a fixed member and a relatively rotatable member mounted on said outer shaft and movable to any of at least two angularly displaced positions with respect to its fixed member upon rotation of said outer shaft, the angular displacement of said relatively rotatable member in moving between said positions being other than the angular displacement between positions of said load element, control handles on said inner and outer shafts for independently rotating said shafts, and said second detent mechanism being self-maintained in set position during operation of said first detent mechanism, whereby the positions of said load member due to rotation of said inner shaft may be increased by movement of said relatively rotatable member from one position to another.

6. In a switch construction having a pair of concentric shafts with the inner. shaft projecting beyond one end of said outer shaft and having a rotary switch element thereon, a first detent mechanism comprising a relatively stationary base member mounted on said outer shaft and a rotatable member connected to said switch element and mounted on the exposed end of said inner shaft, said rotatable mamber and its switch element being movable upon rotation of said inner shaft to center said switch element in any one of a plurality of angular displaced positions with respect to said base member, a second detent mechanism comprising a fixed member and a relatively rotatable member mounted on said outer shaft and movable to any of at least two angularly displaced positions with respect to its fixed member, the angular displacement of said relatively rotatable member in moving between said positions being other than the angular displacement between positions of said switch element, control handles on said inner and outer shafts for independently rotating said shafts, and said second detent mechanism being self-maintained in set position during operation of said first detent mecahnism, whereby the positions of said switch member due to rotation of said inner shaft may be increased by movement of said relatively rotatable member from one position to another.

References Cited in the file of this patent UNITED STATES PATENTS 433,753 Taylor Aug. 5, 1890 597,470 Norden Jan. 18, 1898 755,852 Dennison Mar. 29, 1904 1,036,690 Novak Aug. 27, 1912 1,196,976 Pembroke Sept. 5, 1916 1,861,937 Philips June 7, 1932 2,097,619 Grimes Nov. 2, 1937 2,130,219 Allison et al Sept. 13, 1938 2,233,950 Lepetit Mar. 4, 1941 2,399,906 Bentley May 7, 1946 2,459,564 Latta Jan. 18, 1949 2,465,720 Flamm Mar. 29, 1949 2,498,835 Brotman Feb. 28, 1950 2,604,554 Jacobi July 22, 1952 2,638,015 Schoelles May 12, 1953

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