US1812820A - Clamping lever for planes - Google Patents

Description

June 30, 1931. J. M. BURDICK CLAMPING LEVER FOR PLANES Filed March 15, 1950 PatenteclJune 30, 1931 1,812,820

UNITEDSTATES PATENT OFFICE Application .filed March 15, 1930. Serial No. 436,062.

Thisinvention'has' to do broadlyfwith the in the lever arm' extends forwardly rather art of planesand'ismorepartioularly conthan re-arwardly it is possible and practical cerned with those planes having clamping to provide a much longer lever arm under devices for :clamping the cutting blades in the same conditions as'io limitations of space.

operative position. Other objects will be in part obvious and 55 Aplane' which is typical of the now known in, part pointed out more in detail hereindevices of this character ordinarily includes a after. blade and a clamping member for holding The invention accordingly consists in the the bla'de'inproper operative position, and features of construction, combination of elewhich clamping member has associated therements and arrangement of parts which will so with-"a lever which'may be moved into difbe exemplified -in the construction hereinferentpositions to clamp or release the blade after set forth and the scope of the applica' as the case may be; Prior to this invention it tion of which will beindicated in the aphasbeen the practice to have this lever dispended claim.

posed rearwardly of the plane and mounted For afull and more complete. un'derstand- 65 in the end portion of the clamping member, ing of the invention, reference may be had to which portion was bifurcated. The lever the following description and accompanying itself wasusually of'a curved 'construction'to drawings, wherein provide: one end which engaged the blade, Figure l is a side view, partly in elevation and'at the same time provided a finger grip and partly in section, of a plane construc- 70 intermediate the ends of the lever. 7 tion embodying the improvements of this The present inventioinc onforms' to the'invention. In this view certain parts of the prior artpractice insomuch as a clamping plane have been omitted to more clearly bring member together witha lever is provided to outthe details important'to the invention.

. hold the blade of the plane in position. How- Figure 2 is a detail plan view ofa clamping I ever, the *various features" associated with member, together with the lever in clamping the-leverar'rangementwhich characterize the position, and prior art const'ructions are departed from Figure 3 is a view in side elevation of the I with material advantages'resulting from the clamping member shown in Figure 2, the

departure. full line position indicating the lever in the 90 An important objectin view is to provide, position in which the blade is released, with in -a'-plane construction, a clamping lever the dotted'lines bringing out the clamping whichextends forwardly of'the plane and position of the lever.

wheni'n clamping position lies fiati against Referring now to the "drawings, a plane the clamping member. Incarrying out this construction of a well-knowntype is shown idea in a practical embodiment, the clamping generally in Figurel, with certain parts such member is formed with a closed slot in which as the frog omitted. Briefly describing some the "lever ispivotally mounted. The latter of the parts which are present in a convenhas, at its freeextremity, a transverse piece tional type of plane, it is noted that the illuswhich renders the lever construction what is, trated construction comprises a plane bottom in efi'ect a so-called T-lever. This trans- 10 which has at its front end a knob 11 and verse piece projects beyond thefclamping' at its rear end a handle 12. Intermediate the member at each side thereof to provide at knob '11 and thehandle 12 are located the I each'side a finger grip for'operating the lever. several instrumentalities constituting the es- In the arrangement justnoted the mechanical sential parts of the plane. These include a advantage "of 'the full length of thelever arm wedge-shaped block member 13 which is car is obtained, which'fis in contrast with the 'ried by the plane bottomlO and against which priorart constructions wherein the finger bears a blade 14 having a cutting edge 15! exgrip' is disposedintermediate the ends of the tending through a slot 16 in the plane bottom lever." Moreover, in an arrangementwhere- 10. This blade'is provided with an opening through which extends a screw member 17 having a headed end 18. This screw member 17 is threaded into the block 13 and cooperates with the clamping member to be hereinafter described to hold the blade 14 in position. A means for adjusting the position of the blade in the plane is shown in the form of the mechanism associated with an adjusting nut 19.

A clamping member 20, which is clearly shown in Figures 2 and 3, has a front edge A cam member 27 is pivotally mounted in the,

slot 23 on a pin 28 extending thereacross; and extending from'the cam member 27 is a lever arm 29 which terminates at its extremity in a crosspiece 30. When the lever arm is in the position shown in Figure 2 the crosspiece 30 has extremities 31 which pro ect beyond the sides of the clamping member 20 to provide for easy clamping of the crosspiece by the finger of an operator.

Intermediate its ends, the clamping member 20 is formed with a keyhole slot 32 which receivesthe screw 17.

In the operation of the foregoing mechanism the blade is first adjusted into a desired position whereupon the V clamping member 20 is placed over the screw 18 and moved downwardly to cause the head 18 to fit over the sides of the narrow portion of thekeyhole slot 32. During this operation the T-shaped clamping lever 29 is in the upstanding posltion shown in'full lines in Figure 3. After the clamping member 20 has been properly positioned with respect to the screw 17 th s lever 29 is swung forwardly down into a position wherein it lies flat against the member 20, with the crosspiece 30 in the positlon shown in Figure 2. This operation serves to rotate the cam member 27 about the pin 28 as an axis to urge the portion 25 of the spring 24: away from the clamping member 20. What this operation does in effect is to move the rear end of the clamping member 20 outwardly with respect to the blade 14 to positively clamp: the latter in proper operatlve position.

When it is desired to release the blade by removal of the clamping member, the opera tor grips the extremities 31 of the transverse piece 30 with his fingers and moves the clamping lever into'the position shown in Figure 3. It is evident that this operation has been rendered comparatively easy due to the fact that the mechanical advantage accompanying the full use of the lever arm 29 is obtained. Moreover, a side finger grip is provided which is attained comparatively easily, owing to the disposition of the extremities 31 of the crosspiece 30 which project beyond the sides of the member 20, whereby the under surface of these projections is maintained free and in a condition permitting of the ready gripping thereof.- I

The construction above described has the advantage of not only providing a pleasing appearance effect, but also a compact structure which may be accommodated in the space conditions of the now known types of planes, and which at the same, time provides for increased leverage vduefto the disposition of the lever arm. From the manufacturers view point theconstruction is desirable because the T-shaped clamping lever "is more easily manufactured than the prior artcounterparts of this device which ordinarily are of a curved and ribbed design. By locating the cr'osspiece 31 at the extremity-of the lever arm the full benefits of the latter are availed of which heretofore has not been the case. A further advantage to be noted in connection with the foregoing clamping construction is that the clamping'member itself is formed with a closed slot therein, which is to be contrasted with the prior art practice of mounting the clamping member in the bifurcated end of the clamp. In the instant construction improved properties of strength and resistance to use accompany the closed slot design. c

It will further be observed that in the operation'of the T-lever' from the inoperative position to an operative one it is swung downwardly and forwardly, thatis, it is moved in the general direction in which it is desired to urge the .clampingg plate or member20 so as to insure that the screw 18 fits in the smaller upper end of the keyhole slot. When it is desiredto dis-assemble the parts, the T-lever is moved upwardly and rearwardly, andin the same general direction as that 'inwhich the'clamping member is moved to disengage the latter from the I screw 18. n V c As-many changes could be made in the above construction and many apparently.

widely different embodiments of this invention could, be madefwithout departing from the scope thereof, it is'intended that all matter, contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 7

It 's also to be understood that the language used in the following claim is intended to cover allof the generic and specific features of theinventionherein described and J all statements of theisc ope of the invention which, as a matter of language might be said to fall therebetween.

What is claimed is A plane comprising a plane body, a blade mounted on said body, a clamping plate between Which and said plane body said blade is located, said clamping plate being reduced in Width at its rear end, and a clamping lever pivoted to the rear end of said clamping plate and having a cam, said lever also having a flat T-shaped arm extending forward- 1y of the plane from its pivotal connection With the clamping plate and lying flat against the clamping plate When in damp ing position, the stem of said arm being located in the medial longitudinal line of said clamping plate and the cross-piece of the arm extending across the reduced portion of the clamping plate and having its ends projecting beyond the sides thereof When the lever is in clamping position.

JAMES BURDICK.

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