US3317187A

US3317187A - Scissors jack

Info

Publication number: US3317187A
Application number: US525588A
Authority: US
Inventors: William J Steppon
Original assignee: Ryerson and Haynes Inc
Current assignee: Ryerson and Haynes Inc
Priority date: 1966-02-07
Filing date: 1966-02-07
Publication date: 1967-05-02
Anticipated expiration: 1984-05-02

Description

y 2, 1967 w. J. STEPPON 3,317,187

SCISSORS JACK I I 2 Sheets-Sheet 1 Filed Feb. 7, 1966 INVENTOR WILLIAM J. STE PPON 16.3 V W W ATTORNEYS y 2, 1967 w. J. STEPPON 3,317,187

SGISSORS JACK Filed Feb. 7, 1966 2 Sheets-Sheet 2 INVENTOR WILLIAM J. STEPPON @AWWQWS ATTORNEYS U *d s P 3,317,187 H1116 t3IS 2ltI1t C V patented May 2, 1967 FIG. 1 is an elevational, perspective view of a scissors 3,317,187 jack in accord with the invention shown in the partially SCISSORS JACK William J. Steppon, Jackson, Mich., assignor to Ryerson & Haynes, I'nc., Jackson, Mich, a corporation of Michigan 'Filed Feb. 7, 1966, Ser. No. 525,588 9 Claims. (Cl. 254-126) The invention pertains to load lifting devices and particularly relates to scissor jacks.

Jacks of the scissors type wherein a plurality of pivotally interconnected links are adjusted by means of a screw have recently found increased usage with automobiles as emergency equipment for tire changing. Scissor jacks may be employed directly below the vehicle undercarriage, are of compact storage size and configuration, and are simple to use, yet dependable in operation. While an automobile jack used for the purpose of changing tires is usually operated only a few times during its life, the jack must be dependable and safe in operation and operable at all times, and the scissors-type jack has been experiencing increased popularity as standard equipment with new automotivetype vehicles.

It is an object of the invention to provide a scissors jack which may be used with automotive-type vehicles wherein the jack is of a rugged, high strength construction, dependable and safe in use, may be readily manufactured and assembled, and may be constructed from economically produced components.

Another object of the invention is to provide a scissors jack of unusually high strength, wherein one of the links of the jack is formed of an elongated member having a channel configuration, and wherein one end of this member defines a yoke and the other end thereof forms a convex bearing surface for sliding cooperation with the jack load rest.

An additional object of the invention is to provide a scissors jack employing a load rest which is pivotally mounted to one set of links of the jack and is slidably engaged by the end of another jack link, and the load rest is of such a configuration that extra lift or elevation of the load rest is obtained as the jack approaches its maximum elevation position.

A further object of the invention is to provide a linkage for a scissors jack which is of an integral channel-shaped, transverse cross section and includes a convex bearing surface at one end. The bearing surface of the formed link is manufactured by economical stamping procedures, and is of high strength characteristics, and includes a hinge portion supported on its end by side portions of the channel member.

Yet another object of the invention is to provide a method of forming a channel-shaped-scissors jack link having a convex bearing surface at one end wherein the bearing surface is defined by a tongue formed from the base portion of the channel configuration, and the tongue is supported by the leg portions of the channel configuration.

Another object of the invention is to provide a scissors jack link of a channel-shaped, transverse cross section wherein one end of the link is in the shape of a yoke and each of the yoke portions includes a pivot pin receiving opening. The pivot pin receiving opening includes a throat or entrance portion which intersects an edge of the associated yoke portion permitting ready assembly of the link to the jack structure. Additionally the yoke portion includes a deformable portion wherein a pivot pin may be locked Within the pin receiving recess once the link is properly assembled to the pivot' pin.

These and other objects of the invention arising from the details and relationships of the components of an embodiment thereof will be apparent from the following description and accompanying drawings wherein:

elevated position, portions of the structure being cut away for purposes of illustration,

FIG. 2 is an elevational view of a scissors jack in accord with the invention when fully retracted, a portion of the load rest mounting linkage being cut away to illustrate the relationship of the load rest to the pivot stud,

FIG. 3 is an enlarged, detail, elevational, sectional view of the load rest and associated links during elevation in accord with the invention,

FIG. 4 is a side elevational view of the formed channel jack link in accord with the invention,

FIG. 5 is a plan view of the link of FIG. 4,

FIGS. 6, 7 and 8 are elevational, sectional views taken through the link of FIG. 4 along sections VIVI, VII VH, and VIII-VIII, respectively,

7 FIG. 9 is a plan view of the end of the blank from which the channel-shaped link of FIG. 4 may be formed, prior to folding of the blank, and

FIG. 10 is an elevational, detail view of a modification of pivot pin receiving opening and throat defined in a yoke portion. 7

The arrangement of the components of a scissors jack in accord with the invention will be appreciated from FIGS. 1 and 2. The jack includes a base 10 preferably formed of a sheet material fabricated by a stamping and bending operation. The base 10 includes a substantially horizontally disposed portion 12 from which depend vertically extending spaced wall portions 14. A pair of spaced,

parallel pivot pins

16 and 18 are mounted on the base wall portions 14 and extend thereacross. The pivot pin 16 serves as the support for the jack link 20 and the pivot pin 18 supports the jack link 22. The link 20 and the link 22 each consists of a pair of spaced, parallel, stamped

metal elements

24 and 26, respectively, having a lower end through which the associated pivot pin extends. The pivot pins are each provided with a sleeve spacer 28 circumscribing the central region of the pivot pin to maintain the spacing and separation of the elements of a common link. As is the usual practice, the lower ends of the link elements of the links 20 and 22 are each provided with meshing gear teeth 30, whereby pivoting of the links with respect to the base 10 is controlled, and the links 20 and 22 will pivot in an equal manner relative to the base during operation of the jack.

The jack also includes a link 32 and a link 34, each having an upper end and a lower end. The link 32 consists of a pair of stamped, parallel elements 36 and the link 34 is of a channel transverse cross-sectional configuration which will be more fully described later. The lower end of the link 34 is formed as a yoke defined by a pair of spaced link portions 38.

The upper ends of the link elements 24 are pivotally mounted upon pivots 40 extending from opposite ends of a block 42 interposed between the link elements, FIG. 1. H FIG. 1 only one of the pivots 40 is shown, in that the other extends away from the viewer. The lower end of each of the link elements 36 is provided with a hole through which a pivot 40 extends, and the pivots 40 are swaged at 44 to maintain the

link elements

24 and 36 thereon in a pivotal manner.

The link elements 26 are pivotally mounted upon pivots 46 extending from the end surfaces 48 of a block 50. Also, the yoke portions 38 of the link 34 are disposed adjacent the block surfaces 48 and are formed with an opening for receiving the pivots 46. In this manner it will be appreciated that the upper end of the link 20 is pivotally connected to the lower end of the link 32, and the upper end of the link 22 is connected to the lower end of the link 34.

The block 50 is provided with a bore through which the cylindrical shank 52 of an adjusting screw 54 extends. The adjusting screw 54 has a hexagonal head 56 defined on the outer end thereof, and a thrust bearing is interposed between the head 56 and the block 50. The thrust bearing, preferably, consists of a pair of steel washers 58 having a nylon washer 60 inserted therebetween. The adjusting screw shank portion 52 may be staked, or otherwise provided with means disposed adjacent the inside of block 50, to prevent axial movement of the adjusting screw relative to the block but permit rotation of the screw relative thereto. The block 42 includes a threaded bore 62 through which the threaded portion of the screw shaft 54 extends.

The link elements 36 pass on each side of the link 34 and a pivot stud 64 extends through holes in the link elements 36 and the link 34 to pivotally connect the

links

32 and 34 together.

The upper end of the link 32 is provided with a pivot pin 66 upon which the channel-shaped load rest 68 is pivotally mounted. The load rest 68 includes a base portion 70 from which depends side portions 72 which are in spaced, parallel relation to each other. The load rest base portion 70 is of a nonplanar, concave configuration, as will be apparent from FIG. 3, and includes a convex undersurface 74 adapted to be slidingly engaged by the upper end of the link 34. The load rest base portion 70 is of a configuration wherein when the ends of the load rest are substantially horizontally related, the lowermost portion of the base portion underside as represented at 76 occurs well toward the pivot pin 66 with respect to the right load rest end, FIG. 3. The purpose of the convex configuration of the load rest surface 74 is to increase the elevation of the load rest base portion as the jack approaches its maximum elevation, and this operation will be more fully described later in the specification.

With some vehicles it is desirable that a frame engaging saddle be affixed to the load rest, and such a saddle is shown in dotted lines in FIG. 3. The saddle 78 may be of sheet material and includes a groove 80 in which a rib or projection defined on the underside of the vehicle body may be received.

The link 34 is of a channel-shaped, transverse cross section including a base portion 82 from which dpeends lateral side portions 84 terminating in side edges 86. A longitudinally extending depression is, preferably, formed in the base portion 82 for increasing the resistance of the link to bending. The link side portions 84 are each formed with a hole 88 intermediate the ends of the link for receiving the pivot stud 64. Adjacent each of the holes 88 defined in the side portions, the side portions are deformed outwardly at 90 to define outer edges which serve to space the link elements 36 when the jack is assembled.

The lower end of the link 34, as previously mentioned, is defined by a yoke formed from extensions of the side portions 84 to form yoke portions 38 which are outwardly related to the side portions 84. Each of the yoke portions 38 is formed with an end edge 92 and a lower edge 94 which lies on the same plane as the side portion edges 86. An opening 96 is defined in each of the yoke portions 38 and is preferably of a circular configuration capable of receiving a pivot 46 of the block 50. A slot, or throat 98, is defined in the yoke portions 38 intersecting the end edge 92. The throat 98 is of a normal transverse dimension capable of slidably receiving the pivots 46 whereby the yoke may be assembled to the block 50. After the yoke side portions 38 have been slipped over the pivots 46, the yoke is deformed by swaging, or similar operation, in a direction indicated by the arrows 100, FIG. 4, to reduce the transverse dimension of the throat 98 to such a dimension as to prevent the pivots 46 from leaving the openings 96 and entering into the throat whereby the yoke could be removed from the pivots. After the yoke portions 38 have been deformed, the yoke will be permanently connected to the pivots 46, yet a pivot interconnection between the link 34 and the block 50 will be maintained as the pivots will be rotatably received within the circular openings 96.

As the upper end of the link 34 is adapted to slidingly engage undersurface 74 of the load rest base portion 70, the link upper end is provided with a convex bearing surface 102 which is capable of engaging the load rest undersurface without galling or otherwise damaging the load rest. To provide the convex bearing surface at the upper end of the link 34, a portion of the link member base portion 82 is arcuately bent from the general plane of the base portion in the direction of the side portions 84. The side portions 84 are each formed with a longitudinally extending shoulder 104 immediately adjacent their ends 106 which is substantially parallel to the general plane of the base portion, and a surface 108 is formed in each side portion which intersects the shoulder 104. The surface 108 is perpendicularly disposed to the longitudinal length of the link, and is located inwardly of the associated end 106 of the side portion a distance substantially corresponding to the thickness of the portion of the base portion which is bent toward the side portions. The end 110 of the bent base portion 112 engages the shoulders 104, and the underside thereof engages the surface 108 whereby the relationship which will be apparent from FIGS. 3, 4 and 8 is produced. It will be noted that portion 112 is of a width adjacent its end 110 equal to the normal width of the link 34. In this manner the convex portion 112 is firmly supported and will maintain its arcuate form to define bearing surface 102 even under heavy loads.

A manner of forming the upper end of the link member 34 is illustrated in FIG. 9. The link 34 may be formed from flat sheet steel which is folded to the channel-shaped configuration of the link. When the link 34 is formed in this manner, the arcuate end thereof is formed as shown in FIG. 9 prior to the link being bent into the channel shape. Prior to forming the end of the link, the link blank 114 would have a rectangular end configuration as represented by the dotted lines 116, FIG. 9. The blank 114 is placed within a die and is notched adjacent the end on both sides of the blank central region to define a pair of notches 118. The notches 118 form parallel surfaces 120 which define the maximum width of the tongue 122. Surfaces 124 define the minimum width of the tongue, and the

surfaces

120 and 124 on each side of the tongue are interconnected by an inclined surface 126. Arcua-tely formed surfaces 128 intersect the surfaces 124 and intersect the surfaces 108 which are perpendicularly disposed to the longitudinal axis of the blank. The shoulder surfaces 104 are disposed parallel to each other and to the longitudinal axis of the blank. The ends of the side portions are defined by the surfaces 106, as described above, and the end of the tongue constitutes end 110. After the blank is shaped as shown in FIG. 9,. the blank is folded along longitudinally extending dotted lines 130 to the channel configuration, whereby the side portions 84 are disposed in a substantially parallel rela-' tion on a common side of the general plane of the central base portion 82. The tongue 122, which forms base portion 112, is then bent toward the shoulders 104 to engage the shoulders 104 and surface 108, as shown in FIGS. 3, 4 and 8. The formation of the convex link end does not require welding or other secondary operations after the portion 112 is bent into engagement with the shoulders 104 and surfaces 108. As will be apparent from FIGS. 5 and 8, the width between the surfaces 120 corresponds to the width of the link end and a clean appearing and effective convex bearing surface is provided which is capable of withstanding the loads which will be imposed thereon during ordinary service.

Extension and retraction of the jack is produced by rotating the screw 54 by means of a wrench applied to the hexagonal head 56. Normally, the threads of the screw will be of a right hand whereby clockwise rotation of the screw draws the

blocks

42 and 50 toward each other to extend the jack and raise the load rest 68 relative to the base 10. When the screw 54 is rotated the maximum degree in the counterclockwise direction, the jack will assume the retracted and compact relationship shown in FIG. 2. In FIG. 2 a portion of a link element 36 is broken away to illustrate the presence of the notch 132 defined in each of the side portions 72 of the load rest which provides clearance for the pivot stud 64 and the outwardly formed spacer deformations 90 formed on the link 34 adjacent the pivot stud holes 88.

As the jack is extended from the position shown in FIG. 2 toward the extended position, it will be appreciated that the link 34 will slide relative to the load rest 68. In the fully retracted position of FIG. 2, the convex end of the link 34 extends substantially beyond the load rest and as the jack is extended, the load rest undersurface 74 will slide along the link base portion 82. As the jack approaches its maximum extension, the arcuate, convex bearing surface 102 will engage the load rest undersurface 74, as shown in FIG. 3. Preferably, the undersurface 74 is lubricated to minimize the friction between the load rest undersurface and the convex bearing surface. Further extension of the jack from the position shown in FIG. 3 causes the convex bearing surface 102 to approach and ride on the downwardly depressed portion 76 of the load rest base portion as the convex bearing surface approaches the pivot pin 66. The downwardly depressed portion 76 will cause an increased counterclockwise pivoting of the load rest 68 about the pivot pin 66, FIG. 3, in an upward manner even though little relative sliding movement between the convex bearing surface and the load rest undersurface takes place. Thus, the presence of the downwardly deflected load rest portion 76 permits an extra elevation of the load rest 68 which would not be possible if the load rest base portion were of a planar configuration.

In FIG. a modification of the formation of the pin receiving openingand throat defined in the yoke portions 38 of the link 34 is shown. In FIG. 10 the pivot pin circular opening 134 is located with respect to the associated yoke portions at the same location as the embodiment of FIG. 4. However, the pin receiving slot or throat 136 defined by the surfaces 138 intersects the lower edge 94 of the yoke portions 38', rather than the end 92' thereof, as in the embodiment of FIG. 4. The yoke employed in the embodiment of FIG. 10 is placed on the pivots 46 in the same manner as previously described and after assembly to the pivots 46, the yoke portions 38' are subjected to a force as indicated by the arrow 140 to reduce the dimension of the space separating the throat surfaces 138 and, thus, retain pivots 46 within the circular openings 134.

It will be appreciated that in accord with the invention the link 34 has high strength characteristics. By utilizing the channel-shaped configuration, high resistance to bending of the link 34 is achieved even though the link may be formed of #7 gauge hot rolled sheet steel. The yoke construction at one end of the link permits the link to be readily aflixed to the pivots of the block 50 and the pivot receiving openings and throat defined therein simplify assembly. The construction of the integral convex bearing surface 102 reduces fabrication costs, in that extra material is not required and, yet, an effective nongalling, convex bearing surface is achieved. The support of the bearing surface on the shoulders 104 and surfaces 108 adequately supports the convex bearing surface defining portion 112, and scissor jacks constructed in accord with the invention have continued to operate successfully well beyond the required number of cycles during life determination tests.

It is appreciated that various modifications to the disclosed embodiment may be apparent to those skilled in the art without departing from the spirit and scope thereof, and it is intended that the invention be limited only by the following claims.

I claim:

1. A scissors jack comprising,

(a) a base,

(b) first and second links pivotally mounted on said base, each of said links having a first end and a second end, said links first ends being pivotally mounted on said base,

(c) third and fourth links each having first and second ends,

(d) pivot means pivotally connecting said second end of said first link to said first end of said third link and pivot means pivotally connecting said second end of said second link to said first end of said fourth link,

(e) screw adjustment means interposed between said first and third links and said second and fourth links adapted to vary the spacing between said second ends of said first and second links,

(f) said fourth link constituting an integral, inverted channel-shaped member having a yoke defined at said first end thereof and a convex surface defined at said second end thereof,

(g) a pivot stud pivotally interconnecting said third and fourth links intermediate said first and second ends thereof, and

(h) a load rest pivotally mounted on said second end of said third link, said load rest having a fourth link engageable surface, said fourth link second end convex surface slidably engaging said load rest surface.

2. In a scissors jack as in claim 1 wherein:

(a) said pivot means pivotally connecting said second end of said second link and said first end of said fourth link comprises a spacer block having spaced end surfaces, a pivot extending from each of said end surfaces,

(b) said fourth link yoke including a pair of spaced yoke portions receiving said spacer block therebetween whereby each yoke portion is disposed adjacent a block end surface, and

(c) a slot defined in each of said yoke portions receiving the pivot extending from the adjacent spacer block end surface.

3. In a scissors jack as in claim 2 wherein:

(a) said first, second and third links each comprise a pair of parallel, spaced link elements,

(b) said pivots extending from said spacer block each being pivotally connected to the second end of a second link element.

4. In a scissors jack as in claim 2 wherein:

(a) said slot defined in each of said yoke portions includes a pivot receiving opening of a partially circular configuration and a pivot entrance portion intersecting an-edge of the associated yoke portion and intersecting said pivot receiving opening, said yoke portions being deformed upon said pivots being received within said slots pivot receiving opening to reduce the transverse dimension of said slots pivot entrance portions preventing said pivots from being removed from the associated slots pivot receiving openings.

5. In a scissors jack as in claim 1 wherein:

(a) said load rest fourth link engageable surface comprises an undersurface of a convex configuration whereby movement of said fourth link convex end on said undersurface toward the load rest pivot connection of said load rest on said third link moves the fourth link convex surface over the portion of said undersurface disposed nearest to said base.

6. In a scissors jack as in claim 1 wherein:

(a) said fourth link includes a base portion and spaced, parallel side portions depending from said base portion, said side portions adjacent said fourth link in combination,

second end each being notched to define a shoulder facing in the direction of said base portion, said base portion adjacent said fourth link second end being separated from the adjacent side portions and having an end and being bent toward said side portions notches whereby said base portion end engages said side portions shoulders, said bent base portion defining said convex surface at the second end of said fourth link.

7. A link for a scissors jack comprising,

(a) an elongated channel member having first and second ends, said member including a base portion and spaced side portions depending from said base portion,

(b) a yoke defined at said first end of said member, said yoke being formed by extensions of said side portions longitudinally extending beyond the termination of said base portion adjacent said first end,

(c) a pivot receiving opening defined in each of said portions defining said yoke, said openings being in opposed relation to each other,

((1) means dissassociating said side portions from the base portion adjacent said member second end whereby said side portions each include a free longitudinally extending end and said base portion defines a tongue having an end transversely disposed to the length of said member, and

(e) a shoulder defined on each of said second end side portions adjacent the free end thereof, said shoulders facing toward said base portion tongue, said base portion tongue being arcuately bent to engage the end thereof with said shoulders whereby said tongue forms a convex bearing surface.

8. In a link for a scissors jack as in claim 7:

(a) said member portions defining said yoke each having an end edge transversely disposed to the longitudinal axis of said member and a side edge lying in a plane substantially parallel to the member longitudinal axis,

(b) said pivot receiving openings including an enlarged portion and a throat portion intersecting one of said yoke portion edges and intersecting the associated opening enlarged portion, said throat portion being of lesser transverse dimension than the associated opening enlarged portion and defining a deformable portion on said associated yoke portion.

9. In a link for a scissors jack as in claim 7:

(a) a pivot stud opening defined in each of said side portions intermediate said first and second ends, said pivot stud openings being in opposed coaxial relation having an axis perpendicularly related to the member longitudinal axis,

(b) said side portions surrounding said pivot stud openings being deformed outwardly with respect to said member defining spacer means adjacent said pivot stud openings.

References Cited by the Examiner UNITED STATES PATENTS 1,954,558 4/1934 Conrad 254126 2,071,470 2/1937 Marlowe 254-l26 3,203,670 8/1965 Farris 254-122 3,259,369 7/1966 Gridley 254-122 WILLIAM FELDMAN, Primary Examiner. OTHELL M. SIMPSON, Examiner.

Claims

1. A SCISSORS JACK COMPRISING, IN COMBINATION, (A) A BASE, (B) FIRST AND SECOND LINKS PIVOTALLY MOUNTED ON SAID BASE, EACH OF SAID LINKS HAVING A FIRST END AND A SECOND END, SAID LINKS'' FIRST ENDS BEING PIVOTALLY MOUNTED ON SAID BASE, (C) THIRD AND FOURTH LINKS EACH HAVING FIRST AND SECOND ENDS, (D) PIVOT MEANS PIVOTALLY CONNECTING SAID SECOND END OF SAID FIRST LINK TO SAID FIRST END OF SAID THIRD LINK AND PIVOT MEANS PIVOTALLY CONNECTING SAID SECOND END OF SAID SECOND LINK TO SAID FIRST END OF SAID FOURTH LINK, (E) SCREW ADJUSTMENT MEANS INTERPOSED BETWEEN SAID FIRST AND THIRD LINKS AND SAID SECOND AND FOURTH LINKS ADAPTED TO VARY THE SPACING BETWEEN SAID SECOND ENDS OF SAID FIRST AND SECOND LINKS, (F) SAID FOURTH LINK CONSTITUTING AN INTEGRAL, INVERTED CHANNEL-SHAPED MEMBER HAVING A YOKE DEFINED AT SAID FIRST END THEREOF AND A CONVEX SURFACE DEFINED AT SAID SECOND END THEREOF, (G) A PIVOT STUD PIVOTALLY INTERCONNECTING SAID THIRD AND FOURTH LINKS INTERMEDIATE SAID FIRST AND SECOND ENDS THEREOF, AND (H) A LOAD REST PIVOTALLY MOUNTED ON SAID SECOND END OF SAID THIRD LINK, SAID LOAD REST HAVING A FOURTH LINK ENGAGEABLE SURFACE, SAID FOURTH LINK SECOND END CONVEX SURFACE SLIDABLY ENGAGING SAID LOAD REST SURFACE.