US3738180A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control devices
Assignee: Fiat SpA
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Filing: 1971-05-26
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Granted: 1973-06-12
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Expires: 1991-05-26
Abstract
Abstract A control device suitable for the fuel injection pump of an internal combustion engine is shown. The device comprises a rotatable cam having a plurality of symmetrical lobes and a cam follower having two rollers which are both in contact with the cam face. The cam follower is linked to an operating member of an associated pump. The rollers of the cam follower are relatively large to withstand the forces produced at high speed and the pivot for the cam follower is arranged so that it does not obstruct the space between the two rollers. The cam profile is so shaped that the two rollers are both always in contact with the surface of the cam so that there is no play in their movement.
Inventors
- 👤 G Sola
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:26
CPC Classifications
F; F02; F02M; F02M59/00; F02M59/02; F02M59/10; F02M59/102; F02B; F02B2275/00; F02B2275/14; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10T; Y10T74/00; Y10T74/18; Y10T74/18056; Y10T74/1828
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
227 words
A control device for a fuel injection pump of a multicylinder internal combustion engine, said control device having a casing, a cam rotatably mounted in the casing, said cam having a surface including a plurality of lobes, each said lobe being symmetric about a radial line passing through the top dead center of said lobe, cam follower means comprising a rocker arm having at each end thereof a roller, said rollers both being in contact with the surface of said cam, a support member attached to the casing support means on said rocker arm cooperating with said support member to support said rocker arm for pivotal movement about an axis intermediate said rollers, said support means being outside the region between said rollers and a connecting rod having one end operatively connected to one of said rollers and the other end connected to a cursor slidable in said support members, said cam surface being shaped such that the part of the profile of each lobe of said cam between the top dead center position and the half lift position of said cam follower is determined to be the appropriate envelope of the successive positions of said roller when the other said roller moves over the part of the profile of said cam between the bottom dead center position and said half lift position of said cam follower.
Claim 2
Dependent Claim
227 words
A control device for a fuel injection pump of a multicylinder internal combustion engine, said control device having a casing, a cam rotatably mounted in the casing, said cam having a surface including a plurality of lobes, each said lobe being symmetric about a radial line passing through the top dead center of said lobe, cam follower means comprising a rocker arm having at each end thereof a roller, said rollers both being in contact with the surface of said cam, a support member attached to the casing support means on said rocker arm cooperating with said support member to support said rocker arm for pivotal movement about an axis intermediate said rollers, said support means being outside the region between said rollers and a connecting rod having one end operatively connected to one of said rollers and the other end connected to a cursor slidable in said support members, said cam surface being shaped such that the part of the profile of each lobe of said cam between the top dead center position and the half lift position of said cam follower is determined to be the appropriate envelope of the successive positions of said roller when the other said roller moves over the part of the profile of said cam between the bottom dead center position and said half lift position of said cam follower.
Claim 3
Dependent Claim
95 words
The device of claim 1, wherein said rocker arm comprises two plate-like elements, each said plate-like element having substantially the form of an isosceles triangle with rounded vertices and with a base longer than the sides, a bridge element rigidly connecting said plate-like eleMents side by side at the vortex opposite said base, said support means including a stub shaft projecting outwardly from each of said plate-like elements, means forming axially aligned apertures in each pair of the other rounded vertices of the plate-like elements an axle means for said rollers disposed in said apertures.
Claim 4
Dependent Claim
128 words
The device of claim 2 wherein said support member for said rocker arm comprises a substantially U-shaped element having in each limb thereof a circular aperture of diameter larger than the diameter of each said stub shaft, a slot in each limb of the U-shaped element, each said aperture communicating laterally with a respective said slot so as to provide a passage of width at least equal to the diameter of each said stub shaft to allow the radial introduction thereof into said aperture, a bush in each said aperture having an external diameter equal to the diameter of the respective aperture, said bush arranged for insertion into said aperture over said stub shaft, said bush serving to lock each said stub shaft in position in said aperture.
Claim 5
Dependent Claim
24 words
The device of claim 3 wherein the base of said U-shaped element has an aperture surrounded by a collar through which said cursor passes.
Claim 6
Dependent Claim
28 words
The device of claim 2 wherein there is provided a bush between each axle for said rollers and the respective apertures in the ends of said rocker arm.
Claim 7
Dependent Claim
107 words
The device of claim 1 wherein said cam has five or more lobes, and wherein a first part of said profile of each lobe, from the bottom dead center position up to the point corresponding with the half lift position of said cam follower means, comprises a concave curve having a radius between 35 and 45 mm, and at least one rectilinear section between said point corresponding to said half lift position of said cam follower and said concave curved section to which it is tangential, said rectilinear section extending to a point which corresponds substantially to a quarter of the lift of said cam follower means.
Claim 8
Dependent Claim
64 words
The device of claim 6, wherein said first portion of said profile of each said lobe comprises a first rectilinear section, said concave curved section with radius between 35 and 45 mm, and a second rectilinear section formed by said rectilinear section extending to said half lift position of said cam follower means, both of said rectilinear sections being tangential to said curved section.
Claim 9
Dependent Claim
65 words
The device of claim 7 wherein, for cams of five to eight lobes, said first rectilinear section subtends an angle between 2* and 5* at the center of said cam, said curved section subtends an angle of between 7* and 9* at said center of said cam and said second rectilinear section subtends an angle between 2* and 5* at said center of said cam.
Claim 10
Dependent Claim
70 words
The device of claim 6 wherein said second rectilinear section of said first part of said profile of said cam lobe which extends at least between said point corresponding substantially to the quarter lift position of said cam follower means and said point corresponding to said half lift position of said cam follower means, has a gradient of between 0.5 and 0.3 mm per degree of rotation of said cam.
Claim 11
Dependent Claim
97 words
The device of claim 6 wherein said second rectilinear section of said first part of said cam lobe, extending at least between said point corresponding substantially to the quarter lift position of said cam follower means and said point corresponding to said half lift position of said cam follower means, has a gradient arranged so that when said device is used with a pump having a diameter no greater than twice the stroke, will provide a theoretical gradient of delivery from said pump of between 30 mm3 and 45 mm3 per degree of rotation of said cam.
Claim 12
Dependent Claim
107 words
The device of claim 1 wherein said two rollers of said cam follower means are a main roller and a subsidiary roller, and a second part of said profile of each said lobe, extending from thE top dead center of said half lift position of said cam follower means, has a convex curve in which the section adjacent said second rectilinear section of said first part of said profile, from said half lift position of said cam follower means to about a three-fourths lift position of said cam follower, has a radius not less than half the diameter of said main roller of said cam follower means.
Claim 13
Dependent Claim
85 words
The device of claim 1 wherein said two rollers of said cam follower means are a main roller and a subsidiary roller, and a second part of said profile of each said lobe, between top dead center and said half lift position of said cam follower means has a radius of not less than one-third of said diameter of said main roller of said cam follower means at the section extending about the position corresponding to the five-sixths lift position of said cam follower means.
Claim 14
Dependent Claim
84 words
The device of claim 1 wherein said two rollers of said cam follower means are a main roller and a subsidiary roller, and a second section of said profile of each said lobe, between top dead center and said half lift position of said cam follower means has a radius of not less than one-fourth of said diameter of said main roller of said cam follower means at the section extending about the position corresponding to nine-tenths lift position of said cam follower means.
Claim 15
Dependent Claim
61 words
The device of claim 1 where said two rollers of said cam follower means are a main roller and a subsidiary roller, and the profile of said peak of each said lobe of said cam, about the top dead center position thereof, has a radius not less than one-fifth of the diameter of said main roller of said cam follower means.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |