US2620048A - Lubricating device - Google Patents

Description

1952 E. w. J. BARRINGTON ET AL 2,620,048

LUBRICATING DEVICE Filed Dec. 23, 1947 2 SHEETS-SHEET l E. .JTBa/rrb ,B abrirueolv I Dec. 2, 1952 E. w. J. BARRINGTON ET AL 2,620,043

LUBRICATING DEVICE 2 SHEETS-SHEET 2 Filed Dec. 25, 1947 Patented Dec. 2, 1952 LUBRICATING DEVICE Edward William Jack Barrington, Ealing, London, andEric Ernest Robinson, North Wembley, England, assignors to Rotax LimitecLLondon,

England Application December 23, 1947, Serial No. 793,506

In GreatBritain November 14, 1946 8 Claims. 1 For the lubrication of various forms of mechanisms it is a known practice to employ a pad "impregnated with a lubricatingoil or grease, and

to arrange it in contact with a rotary part of a mechanism to be lubricated. For example, in

electric spark ignition apparatus for use with internal combustion engines, where a rotary. cam 'is employed for actuating an interrupter, it is known to mountadjacent to the cam a pivotally mounted "lubricant pad which bears on the periphery of theccam.

It has been found that when the mechanism is subject to considerable temperature changes, the amount of-lubricant deposited by the pad whilst satisfactory at the lower temperatures tends to become excessive at the higher temperatures, and the object of the present invention is to provide a simple means forminimising this tendency.

In the accompanying drawings:

.Figure 1 is an elevation, partly in section, of .a lubricating arrangement for the rotary cam of an interrupter in a spark ignition apparatus, constructed in accordance with the invention.

Figure 2 is a plan view of the arrangement.

Figure 3 is an elevation of ca modified form of lubricating arrangement.

Figure 4 isa longitudinal section of the lubricating pad of Figure 3, taken in the direction of the arrow a.

Figure 5 is an elevation of another modified form of lubricating arrangement.

Figure 6 is a longitudinal section of. the lubricating pad of Figure 5, taken in the direction of the arrow -b.

Figures 7 and 8 are longitudinal sections, in different operative states, of another modified form of lubricating pad.

In one convenient manner of applying the invention to the lubrication of the rotary cam of an interrupter in a-spark ignition apparatus as illustrated in Figures 1 and 2, the cam l which actuates the interrupter arm. 2 has lubricant applied to the periphery thereof by means of a pad 3 which is pivotally mounted on a pin 4 extendingfrom the base 5 and is pressed into engagement with the cam by a'spring-fi. A pin 7 of a material harder than the pad is fitted within a hole near the free endoi thepad and'projects slightlybeyond the sides thereof. A pair of bimetallic strips 8 are mounted on the base at opposite sides of the spacer 9 and their free ends extend in parallel relation to embrace the end of the pad 3 containing the pin 1. The arrangement is such that at the lower temperatures the pad is free to oscillate between the strips 8 under the action of the cam and the loading spring 6, the latter being suitably adjusted to cause the pad to exert suificient pressure on the cam to ensure the desired lubricating effect at those temperatures. "But with increase of temperature the free ends of the strips close on to the'sides of the pad to engage the projecting ends of the pin land exert thereon a progressively increasing braking actionwhich results in corresponding decrease of v the pressure between the pad and the cam with consequent avoidance of excessive lubrication.

hi another manner of carrying the invention into effect appliedto a similar interrupter mechanism as illustrated in Figures 3 and 4, the loading spring itself is bi-metallic. The lubricating pad 3 is formed with a central slot [0 extending outwardly from the pivot hole. A bi-metallic ribbon strip H is coiled in helical form upon the pivot pin l2 and one end thereof extends into the slot ID of the'pad, the pivot hole of which is fitted over the helical portion of the strip. The

opposite end of the said strip extends outwardly through a cut-away portion of the pad and is secured to a bracket 13 on the base. The arrangement is such that at lower temperatures the resilience of the bi-metallic-strip exerts sufficient pressure on the pad to ensure the desired lubrication, but as the temperature increases the pressure between the pad and the cam' is progressively reduced. If desired, the bi-metallic strip may be adapted to move the pad clear of the 'cam when the temperature exceeds a given upper limit, but for most purposes it is only required to diminish the pressure between the pad and the cam sufilciently to prevent excessive lubrication.

In another manner of carrying the invention into effect applied to a similar form of interrupter mechanism as illustrated in Figures 5 and 6, the lubricating pad 3 is formed with an interior slot [0 communicating with the pivot as in themevious example. A lei-metallic ribbon strip 14 is wound in the form of a helix upon the post l2 and one end thereof extends into the slot as shown. A coil spring l5 loosely surrounds the helical portion of the bi-metallic strip, one end Iii extending into the slot l0 and the opposite end being anchored to a post ll, the arrangement being such that the spring exerts sufficient pressure on the pad to afford a desirable amount of lubrication at the lower temperatures. The coiled portion of the bi-metallic strip 14 is loose upon the pivot pin l2 at this time, and consequently does not afiect the motion of the pad. The arrangement of the strip is such that as the temperature rises the coiled portion of the strip contracts upon the pin [2 and thereby applies a progressively increasing force retarding the motion of the pad and therefore reducing the pressure between the pad and the cam. Ultimately the pad may be held steady in a position in which it lightly engages the crests of the cam contour.

In carrying the invention into effect according to another mode as illustrated. in Figures 7 and 8, a lubricating pad I8 is pivotally mounted upon a post I9 and friction washers 22 are secured to opposite sides of the pad surrounding the pivot holes. The outer end of the post is reduced and threaded to take a knurled nut 21, and a coil spring is interposed between this nut and the adjacent friction washer 20 which has a reduced central hole fitting the reduced end portion of the post. Interposed between the opposite friction washer and the base are three bimetallic Washers 22 so constructed that they are flat when at ordinary temperatures but assume a dished form when heated, the washers being disposed so that expansion to dished form takes place in opposite directions in adjacent washers. The arrangement is such that at ordinary temperatures with the Washers 22 lying fiat, the friction washer 26 adjacent to the coil spring rests upon the shoulder of the pin it and the pad is freely movable since the coil spring is practically uncompressed in this position which is shown in Figure 7. The pad may be provided with a loading spring and arranged for lubrication of a cam as shown in Figure 1 for example, the spring being adjusted to give the desired amount of lubrication at the lower temperatures. With increase of temperature the bimetallic washers 22 will assume a dished form as shown in Figure 8, thereby forcing the pa d against the coil spring and providing a progressively increasing motion-retarding action on the pad whereby the desired reduction in the lubricating effect is achieved.

By this invention there is ensured substantially uniform lubrication at all temperatures within a normal range of temperature variation in a very simple and satisfactory manner.

The invention is not, however, limited to the examples above described. Further it may be applied in essentially the same manner to other forms of mechanisms.

Having thus described our invention What we claim as new and desire to secure by Letters Patent is:

1. A device for lubricating a rotary member, comprising the combination with said rotary member, of a stationary support, a loaded lubricating pad movably mounted on said support in contact with the periphery of said rotary member, and at least one temperature-responsive member carried by said support, said temperatore-responsive member being deformable by temperature variations, and being arranged to co-operate with said pad for reducing the pressure thereof on said rotary member with increase of temperature.

2. A device for lubricating a rotary member, comprising the combination with said rotary member, of a stationary support, a loaded lubricating pad pivotally mounted on said support in contact with the periphery of said member, the latter being shaped so that rotary movement thereof causes oscillatory motion of said pad, and at least one temperature-responsive member carried by said support, said temperatureresponsive member being deformable by temperature variations, and being arranged to cooperate with said pad to retard oscillatory motion thereof, and thereby reduce the pressure thereof on said rotary member, with increase of temperature.

3. A device for lubricating a rotary member, comprising the combination with said rotary member, of a stationary support, a loaded lubricating pad movably mounted on said support in contact with the periphery of said member, and at least one bi-metallic member carried by said support, said bi-metallic member being deformable by temperature variations, and being arranged to co-operate with said pad for reducing the pressure thereof on said rotary member with increase of temperature.

4. A device for lubricating a rotary cam-like member, comprising the combination with said member, of a stationary support, a loaded lubricating pad pivotally mounted on said support in contact with said member, the latter being shaped so that rotary movement thereof causes oscillatory motion of said pad, and a bi-metallic member carried by said support, said bi-metallic member being deformable by temperature variations, and being arranged to reduce the pressure of said pad on said rotary member with increase of temperature, by exerting on said pad a progressivel increasing motion-retarding action.

5. A device as claimed in claim 4, in which said bi-metallic member has the form of a spring arranged to'urge said pad into contact with said rotary member.

6. A device as claimed in claim 4, and having a spring arranged to urge said pad into contact with said rotary member, said bi-metallic member being arranged to act on said pad in opposition to said spring with increase of temperature.

7. A device as claimed in claim l, in which a pin serving as a pivot for the pad is secured to said support, and in which said bi-metallic member has the form of a coiled strip mounted on said pin and having one end in engagement with said pad, said strip being arranged to grip said pin with increase of temperature.

8, A device as claimed in claim 4, in which a post serving as a pivot for the pad is secured on said support, and in which said bi-metallic member has the form of a washer mounted on said post.

EDWARD WILLIAM JACK BARRINGTON.

ERIC ERNEST ROBINSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,972,907 Shaw Sept. 11, 1934 2,007,217 Rose July 9, 1935 2,265,047 Tognola Dec. 2, 1941 2,421,713 Porter June 3, 1947 2,435,128 Carlson Jan. 27. 1948

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