US2781803A - Cam actuated adjustable hold down clamp - Google Patents

Description

Feb. 19, 1957 J. w. NELSON CAM ACTUATED ADJUSTABLE HOLD DowN CLAMP Filed sepia. 23, 1953 Writ llnited States Patent O CAMACTUATED ADJUSTABLE HOLD DOWN CLAMP John W; Nelson, Minneapolis, Minn.

Applicatonseptember 23, 1953,v Serial No. 381,924

' 2 Claims. (Cl. 1.44-290) This invention relates to adjustable clamps and more particularly to an adjustable safety clamp or vice with latchingzmeans for preventing the accidental unclamping or loosening thereof.

It is an important object of the invention to provide a simplev and eilicient adjustable safety clamp in the` nature of an improvement over the clamp disclosure inv my United States Patent Number 2,157,345 issued May 9`, 1939, and in` my United States patent application Serial Number 289,849 filed May 24,. 1952, and now abandoned. In clamps of this class, the jaw is set frictionally against the work andV in contact with a vertically reciprocablesleeve which extends through the jaw and in binding relation' therewith. The sleeve is forced downwardly by a cam which s actuatedv by a reciprocable handle. In many instances it is not feasible to operate the cam' all the way fromV its uppermost position to the extreme lowerrnost position, the low position being the latching or locking position. The present invention contemplates a latching arrangement wherein the handle and cam element may be stopped at any intermediate position at which suic'ient pressure has been put upon the workpiece to hold it in clamped position with respect to a supporting structure.

Another feature of clamps such as that disclosed in my issued' patent above notedIk and in the above patent application, is the revolvability of the jaw element and of the handle element independently of each other. Thus, a piece of work can be clamped at any circular position aboutl the'body or standard or" the clamp device and at the same time the handle may be rotated to the same` or to any other position which is convenient to the user. However,-since the upper portion of the clamp body or standard is required to be rotatable with respect to the lower or' xed portion and since the uppermost end of' the mounting structure or sleeve must bear a surface cooper ablewith the camon the handle, it becomes necessary to provide for internaly rotation` of the upper end of the standardv with respect to the lower. In4 my previously issued patent, I provide simply for a threaded connection between an eye bolt and the upper end of the standard'. Such arrangement allows complete rotation of the handle but does not preclude the accidental unscrewing of the handle, results of which may be dangerous if a piece of work isv tightly clamped in position when the handle is near its uppermost threaded position. In my abandoned application, I provided for an internal stop means and a tool by which the stop means could be releasably retained until the threaded eye bolt was sutliciently advanced in the' assemblage thereof and, upon release of the tool, would henceforth permit but a single turn of the handle and'prevent; the unscrewing of the threaded eye bolt from the trop of the standard. l found, however, that this arrangement was complicated and that a simpler and more convenient means should be` devised so as to permit the clamp assembly to be put together rapidly and cliiciently, permit independent` rotating of both the handle element and the jaw element through 36V degrees of operability,

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It is therefore another object ofthe invention to providev fori latching means' on the clamp assembly which vvill permit thelhandle element to be positionedat an adequate" angle with respect tothe vertical to frictionally set the jaw member against-the work to be held, yet permitting the handle to operate at anyconvenient radial angle with respect to the axi's of the clamp, the work at all times bcing held firmly with respect to the clamp support.

lt is al further ob'ject of the invention to' provide for a. simple and convenient latch assembly which will be self containedy within the handle and cam and the assembly and disassembly of which can be elected externally of the jaw sleeve.

It is a still further object of the invention to provide a` simple and convenient clamp of the nature described which will be? safe andY reliable in its clamping action and haveanovel and inexpensive latch means' associated with the'pivotal cam connection in a novel and eflicietmanner.

These' 'andv other objects and advantages of my' invention will more fully appear from the followingV descriptionV madefin connection with the accompanying drawings wherein likel reference characters refer to similar parts throughout the several views and in which:

'Fig l is a vertical sectional view of my adjustable clamp with thel handle and cam arrangement in raised'l or non-operative position, parts of the clamp being shown inv full line;

Fig. 2 is a' segmental view of the' upper portion of the@ clamp, certain portions being shown in vertical section to show the relationship of the parts and Fig. 3 is a detailed view of the upper portion of theclamp taken in vertical section with the handle and cani in lower or latched position.

Referring now more particularly to the drawing, the adjustable clamp devicecomprising my invention is shown in an upper or retracted position in Fig; l with the standard 10 and the handle element 11 disposed vertically and in alignment one with the other. The standard' 10 is an' elongated member terminating at one end in securing means 12 for mounting the standard on a support or base such as table top 13. The securing means may comprise simply a washer 14 and nut 15 threadably mounted at the lower end of standard 1i) and in opposition to a second Washer 16 and second nut 17 which can be drawn up to effect a secure mounting through opening 18 disposed in supporting surface 13. The upper end 19 of the elongated body iti is pivotally secured to the handle 11 by means of pivot pin Ztl; The upper end 19 of the elongated standard' preferably constitutes an extension which is aligned generally with the elongated standard 1l) and secured against lengthwise movement while still permitting axial rotation' thereof with respect to the lower portion of elongatedY standard itl. rthe extension 19 may be intertted with the elongated standard lil by means of an annular groove formedy in one of the members and a cooperating abutment secured to the other. ln the form shown in Fig'. l, the extension 19 contains' an annular groove 21 which isformed in the lower end of the extension 19 and within the axial opening 22 formed in the upper end of the main body portion of elongated standard 11i. The lateral' opening is drilled through the standard 10 to receive an abutment such as pin 23 which in turn is adapted to cooperate slidably with the annular groove 21 formed at the lower end of extension 19. The pin 23 is preferably formed of hardenable material which can withstand high stresses and which will intert nicely with the annular groove 21 and permit axial rotationy of the extension 19VV while securely preventing discontinuity between the upper and lower ends of the standard during the operation of the device.

A mounting element 24 is formed in the nature of a sleeve which is slidably received over the elongated standard and is preferably slidable in close fitting relation therewith. The sleeve 24 terminates at its upper end in a cam bearing surface 25 which has an opening 26 formed therethrough for slidably receiving the upper extension 19 of elongated standard 10. Interposed between the inside of cam bearing surface 25 and a shouldered portion 27 of the main body portion of elongated standard 10 is a resilient means such as compression spring 28 for constantly urging upwardly the sleeve member 24.

A clamping jaw 29 has a milled clamping surface 30 and an adjustable connection 31 for engagement with the sleeve 24. The adjustable connection 31 may simply comprise an opening slightly larger than the diameter of sleeve 24 so as to be held against upward movement by canting and frictional engagement with the outer surface of sleeve 24. The latter arrangement of jaw and sleeve is disclosed more fully in my issued Patent Number 2,157,345 previously mentioned in this specification. It should be pointed out that the clamping jaw 29 is positionable at any circular angle about sleeve 24 so as to bring the milled jaw surface in opposed relation with supporting surface 13 and with a piece of work 32 interposed therebetween.

The handle 11 has a cam means 33 formed adjacent and eccentrically with respect to pivot 20, the cam means preferably constituting a pair of matching eccentric ears through which the pivot pin 20 can extend. The cam arrangement is likewise similar to that disclosed in my issued patent and cooperates with the cam bearing surface 25 so as to depress the sleeve 24 when it is desired to effect a clamping of work upon a supporting surface.

interposed between the handle element 11 and an upper position on the elongated standard 10 is a retention means such as the latch assembly 34. The latch 34 may comprise simply a ratchet head 35 having peripheral teeth 36 thereon and a cooperating pawl 37 which is spring pressed thereagainst to prevent movement of handle 11 in a clockwise direction as viewed in Fig. l. The ratchet head 35 is drilled to receive the upper end of extension 19 and is cross drilled to receive the pivot pin 20 as shown. With the arrangement thus described, the pivot pin 20 performs the dual function of fastening in place the ratchet head 35 while at the same time providing a bearing pin for the reciprocation of the handle 11. The pawl 37 is pivotally mounted at 38 within the handle 11 and has a rearward extension 39 to which is pivotally attached a thumb button 40 which in turn extends outwardly through an opening 41 formed in handle 11. A leaf spring 42 is mounted within handle 11 and is interposed between a retaining pin 43 and the extension 39 of pawl 37 so as to urge the pawl against the periphery of ratchet head 35 and in locking engagement with one of the teeth 36 under normal circumstances. When thumb button 4i) is depressed, the pawl 37 will be caused to disengage from teeth 36 and permit the oscillation of handle 11 in a clockwise direction as well as counterclockwise.

In the assembly and operation of my adjustable clamp, I rst insert the extension 19, with the annular groove 21 in interfitting relation with the endwise bore 22 in body 10, and align the groove 21 with the lateral opening 23a drilled transversely of the standard 10 as shown. The abutment pin 23 is then inserted through opening 23a in engagement with the annular groove and the spring 28 is placed over the end of extension 19, the lower end thereof resting against the shouldered end 27 of the standard 10. Sleeve element 24 is then placed over the standard 10 and its extension 19, the opening 26 slidably receiving the outer end thereof. The sleeve 24 is then forcibly depressed and the ratchet head 35 placed upon the uppermost end of extension 19 with the pivotal openings in alignment. The handle element 11 is next brought with t head 35 and that of the extension 19. Pivot pin 20 is then placed in position, extending through the eccentric cam members 33 as well as through the ratchet head 35 and the end of extension 19. The pivot pin 20 is preferably provided with a head 20a and a threadable connection between its opposite end and the nut 20b.

It will be noted that the jaw 29 and the sleeve element 24 may be rotated together or independently through circular angles up to 360 degrees, the jaw 20 thus being available for contact with a workpiece 32 at any point of the compass with respect to the axis of the standard 10. It is also to be noted that handle 11, together with extension 19, may be rotated to any direction of the com- A 29 upon the work 32 as is the case in my previous clamp device disclosed in the above noted patent. Furthermore. the abutment pin 23 can be directly inserted through the standard 10 into operable position with relation to the extension 19 and the annular groove 21 without the aid of any special tools. As a matter of fact, the pin 23 can be quite loosely disposed in the opening 23a since the sleeve 24, when placed over the elongated standard 10 will prevent displacement of pin 23. The novel ratchet head connection permits the placement and removal of sleeve 24 directly over the top of extension 19 when the ratchet head is disengaged therefrom. The pivot pin 20 cooperatively forms a bearing for the handle and cam members while at the same time providing a securing means to retain the ratchet head 35 in position. The

' convenient and simple latch arrangement permits the handle 11 to be positively positioned in clamping relation at any point of the compass, the latch mechanism turning therewith in unison. Since the sleeve 24 is independently rotatable about the same axis of standard 10, it will continuously present new cam bearing surface to the cam members 33. This arrangement will, of course, assist in preventing undue wear at any local area and will prolong the life of the adjustable safety clamp.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of my invention.

What I claim is:

l. In an adjustable safety clamp the combination of an elongated standard having means at one end for securing to a support, an extension secured axially with respect to said standard and in intertitting relation, said securing being accomplished by an annular groove in one of saidextension for engagement with said annular groove to4 permit axial rotation while preventing lengthwise movement of the extension with respect to said standard, a sleeve element surrounding said standard and said extension at least in the area of the juncture between the extension and the standard, said sleeve element having a cam hearing surface at one end thereof and provided with an opening through the cam bearing surface for permitting said extension to extend freely therethrough, a laterally extending work-engaging jaw mounted on said sleeve in opposed relation to a support when the safety clamp is mounted thereon, a ratchet head positionable at the end of said extension, a reciprocable handle likewise positionable at the end of said extension, securing means for releasably retaining both of said ratchet head and said handle in operable position, and cooperating latch mechanism on said handle for engaging with said ratchet head to hold said handle and cam in clamping relation with respect to said sleeve element and said work engaging jaw.

In an adjustable safety clamp, the combination of an arenaria elongated standard having means at one end for securing in upstanding relation with respect to a support, a diminished extension rotatably mounted in alignment with the longitudinal disposition of said standard and secured against relative longitudinal movement therewith, a sleeve slidably mounted in closely tting relation with said elongated standard and having an upwardly facing cam bearing surface annularly disposed. thereon, said sleeve further having closely intertting relation with said diminished extension and relatively slidable on the medial portion thereof, a jaw adjustably mounted on said sleeve in outstanding relation therewith and opposed to said support in operable condition, a ratchet head positionable at the end of said diminished extension, a reciprocable camming handle likewise positionable at the end of said extension and rotatable about the vertical axis of said standard, securing means for releasably retaining both said ratchet head and said handle in operable position with respect to said extension, and cooperating latch mechanism on said handle for engaging said ratchet head to hold the camming handle in clamping relation with respect to said sleeve element and said work-engaging Y jaw, said diminished extension with the ratchet head and handle removed permitting removal and replacement of said sleeve and consequent uncovering and covering of the rotatable union between said diminished extension and said upstanding standard.

References Cited in the tile of this patent UNITED STATES PATENTS

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