US3377088A

US3377088A - Universal boom support

Info

Publication number: US3377088A
Application number: US638966A
Authority: US
Inventors: Arthur B Millay; George W Wilkie
Original assignee: Newport News Shipbuilding and Dry Dock Co
Current assignee: Newport News Shipbuilding and Dry Dock Co
Priority date: 1967-05-16
Filing date: 1967-05-16
Publication date: 1968-04-09
Anticipated expiration: 1985-04-09

Description

April 9, 1968 A. B. MILLAY ETAL 3,377,088

UNIVERSAL BGOM SUPPORT Filed May 16, 1967 Y 3 She ts-Sheet 1 GEORGE W. WILKIE FIG I BYFMMWM ATTORNEYS April 1968 A. B. MILLAY ETAL 3,377,088

UNIVERSAL BGOM SUPPORT 3 Sheets-Sheet 2 Filed May 16, 1967 INVENTORS ARTHUR B. MILLAY &

GEORGE W. WlLKlE WMwWv ATTORNEYS April 1968 A. B. MILLAY ETAL 3,377,088

- UNIVERSAL BOOM SUPPORT Filed May 16, 1967 INVENTORS 6 ARTHUR B. MILLAY 8 GEORGE W. WILKIE 3 Sheets-Sheet 5 ATTORNEYS United States Patent ()fi lice Patented Apr. 9, 1968 ABSTRACT OF THE DISCLOSURE A support for a boom adapted to pass over center for use on either a forward or an after hatch is provided with cams and associated cam followers to provide for athwartship tilting as the boom approaches and passes a vertical position. The bearing member employed is shaped to abut against a substantial area of a depending member attached to the tilted boom. A ball supported in the bearing member is mounted so as to rotate only to permit tilting of the boom.

Background of the invention It is Well known to use a boom which can be moved over center in order to serve either a forward or an after hatch. Reference may be had, for example, to Sparrow et al. Patent 3,110,403 and Sperg Patent 3,286,851. Generally, such booms are provided with conventional boom supports which have been used on booms of all types for many years. It has been found that a conventional boom support is frequently subjected to very high stresses if the boom is moved through the vertical position to shift it from one hatch to another hatch. This problem has been recognized in Gandy Patent 3,176,805 which provides for a structure which permits the boom to tilt to a limited degree as it passes through the upright position to alleviate the stresses in the event that the boom deviates slightly from the true vertical.

The Gandy boom support presents a problem in that the structure which permits the tilting at and near the vertical position of the boom is equally free to tilt when the boom is in any other position of elevation, a serious disadvantage particularly where a split cargo purchase is employed since such tilting in operation causes the purchase to chafe against the boom. Further, it permits movement about a vertical axis which is already accommodated for by mounting the bearing member for rotation about a vertical axis. This causes unnecessary wear of the tilting mechanism. In addition, the jaws of the Gandy structure imposed undue stresses on the bearing member by making only a line contact with the bearing member.

Summary of the invention The universal boom support of the invention has a base in which a bearing member is mounted for rotation about a substantially vertical axis. The bearing member has opposite sides each having an opening for the passage of means to secure the conventional dependin portions of a boom heel. A ball is mounted in the bearing member and is connected to the bearing member to restrict its rotation to a single axis which is substantially horizontal. A boom heel with conventional depending portions has the said depending portions pivotally connected to the ball. The depending boom heel portions are each provided with a cam follower engaging a cam surface on the adjacent side of the bearing member, each cam surface having a low portion to provide for the limited tilting of the boom as it approaches and passes through the vertical position and high portion to prevent the boom from tilting at normal operating elevations. Each side of the bearing member slopes inwardly to permit the adjacent depending portion of the boom heel to lie fiat against a substantial portion thereof when maximum tilt of the boom is achieved.

It will be apparent that this structure is advantageous in that the movement and consequent wear on the ball is limited to the desired tilting when the boom is being moved from an after hatch to a forward hatch or vice versa. Further, undue stresses on the bearing member in which the ball is mounted are eliminated.

Drawings FIGURE 1 is a rear elevation, partially broken away, of a universal boom support in accordance with the invention;

FIGURE 2 is a vertical section, partially broken away, taken on a plane indicated by the line 22 in FIGURE 5 with the boom heel attached;

FIGURE 3 is a vertical section taken on the planes indicated by the line 33 in FIGURE 1;

FIGURE 4 is a vertical section taken on the plane indicated by the line 44 in FIGURE 1;

FIGURE 5 is a front perspective view, partially broken away, of the bearing member and ball of the boom support of FIGURE 1; and

FIGURE 6 is a side perspective view of the ball and pin of the boom support of FIGURE 1.

Preferred embodiment Referring first to FIGURE 1, a universal boom support 2 has a base 4 mounted on 3. ships deck indicated at 5. Base 4 has a vertical bore 6 which receives a pin 7 fixedly secured to bearing member 8. Bearing member 8 is provided with a horizontal flange 10 which rests on the top of base 4.

Bearing member 8 is provided with a lower spherical surface indicated at 16, and a removable cap 18 having an inner spherical surface 20. As best seen in FIGURE 3, cap 18 is held in position by means of

machine screws

22, 22.

Sides

24 and 26 of bearing member 8, which are mirror images of each other, are respectively provided with

openings

28 and 30.

A ball 34 is mounted inside bearing member 8, being held in position by cap 18. Ball 34 is provided with a pair of opposite openings, 36, 36 (only one being shown in FIGURE 5) each of which receives a stub shaft 38. Each stub shaft 38 is received in an opening 40 formed in bearing member 8 (only one opening 40 being shown in FIGURE 5) to mount the ball for pivotal movement within bearing member 8 only on the axis passing through

shaft

38, 38.

A boom heel member 44 is secured as by welding to the lower end of a boom 46 and has a pair of spaced depending

members

48 and 50 provided with

openings

52 and 54 respectively. A pin 56 having a head 58 provided with a chamfered portion 60 and a threaded end 62 for the reception of a nut 64 passes through opening 54, opening 30 in bearing member 8, a central bore 68 in ball 34, opening 28 in bearing member 8, and opening 62. The pin is held in place by nut 64. Chamfered portion 60 engages a bar 70 welded to depending member 50 which causes pin 56 to rotate with heel member 44. A spacer ring 74 keeps depending member 48 spaced from ball 34 and a spacer ring 76 keeps depending member 50 spaced from ball 34.

Each of

sides

24 and 26 is provided with an upper cam 80 and a lower cam 82. Cam 80 has a raised portion 84 and sloping

faces

86 and 88. Cam 82 has a raised portion 90 and sloping

faces

92 and 94, the areas between sloping

faces

86 and 92 and 88 and 94, respectively, in

effect form cam low portions. Each of the depending

portions

48 and 50 is provided with a pair of diametrically opposed

cam followers

96, 96 which are adapted to cooperate with raised

portions

84 and 90 of the

adjacent earns

80 and 82 being engaged therewith when the boom is in normal operating positions. Each of

sides

24 and 26 of bearing member 8 is provided with chamfered

portions

104 and 106, respectively, to provide for substantial bearing surfaces to be engaged by the inner

flat faces

108 and 110 of depending

members

48 and 50, respectively.

Operation In operation, boom support 2 is free to move about a vertical axis by virtue of the rotatably mounted pin 7. Raising and lowering of the boom is freely permitted by virtue of the rotation of pin 56 within ball 34. The engagement of

shafts

38, 38 in bearing member 8 on an axis lying in a plane perpendicular to the axis of pin 56 prevents the rotation of ball 34 as the boom is being elevated or lowered and similarly prevents ball 34 from rotating about a vertical axis.

During normal operation, earns 96, 96 on each of

dependent members

48 and 50 are in contact with the raised

portions

84 and 90 respectively of the

adjacent cams

80 and 82 to prevent the movement of boom heel member 44 and boom 46 in a plane passing through the axis of pin 56 and the axis of boom 46. However, when it is desired to move the boom 46 through a vertical position to shift, for example, from an after to a forward hatch,

cam followers

96, 96 on depending

members

48 and 50, respectively, are carried clear of the raised

portions

84 and 90 of

adjacent earns

80 and 82 permitting a tilting movement of heel member 44 and boom 46 in the event that the boom is not in a truly vertical plane. The limit of tilting is determined by the engagement of one of

faces

108 and 110 with the adjacent chamfered portion 104 and the engagement of the other face with the adjacent chamfered portion 106 depending upon which way the boom tilts. Preferably arthwartship tilting of from about 2 to about 3 /z to either side is provided for. Advantageously, freedom for tilting will be provided for about to about preferably about 15, forward and after the vertical topped position of the boom as it passes from a forward to an after hatch or vice versa. After passing the substantial vertical position and being lowered in the other direction,

cam followers

96, 96 will engage sloping portions on the

adjacent cams

80 and 82 depending upon the direction of movement of heel support member 44 and boom 46 to be cammed upwardly onto the high portion of the cams and again restrain the movement of support member 44 and boom 46 in a plane passing through the axis of pin 34 and the axis of boom 46.

It will be understood that the above described embodiment is intended to be illustrative and not limiting.

We claim:

1. A universal boom support comprising:

a base,

a bearing member having two opposite sides each with an opening therethrough,

means mounting the bearing member for rotation on the base about a substantially vertical axis,

a ball mounted in the bearing member,

means limiting the movement of the ball in the bearing member to rotation on a substantially horizontal axis,

a heel member adapted to be secured to the lower end of a boom and having spaced heel portions,

means pivotally connecting the spaced heel portions to the ball adjacent the openings through the sides of the bearing member,

cam means on each opposite side of the bearing member,

a cam follower on each spaced heel portion for respective engagement of the cam means,

each of said cam means having a low portion to provide for limited tilting of the heel member when the heel member is in the vicinity of a vertical position and out of its normal operating position and a high portion to prevent such tilting when the boom is in normal operation.

2. A boom support in accordance with claim 1 in which the ball has an opening thercthrough in alignment with the openings in the sides of the bearing member, the depending portions have openings in alignment with the openings in the sides of the bearing member and a heel pin passes through the openings in the depending portions, the sides of the bearing member and the ball.

3. A boom support in accordance with claim 2 having means to look the pin against relative rotation with respect to the depending portions.

4. A boom support in accordance with claim 1 in which a portion of each side of the bearing member is chamfered to be parallel to and in contact with a substantial portion of the adjacent depending portions when the boom is tilted to move against the bearing member and spacer rings space the depending portions from the ball.

References Cited UNITED STATES PATENTS 663,109 12/1900 Tucker 212- 3,176,805 4/1965 Gandy 287-87 3,210,103 10/1965 Montgomery 28787 EVON C. BLUNK, Primary Examiner.

H. C. HORNSBY, Assistant Examiner.