The present invention relates to a hack saw and more particularly to a close quarter hack saw which has a replaceable blade.
Close quarter hack saws have been known for a number of years. They consist of a frame in the form of a handle with a hack saw blade mounted on and extending from the front of the handle. However, some of such close quarter hacksaws may not easily be used for effective close quarter work. In others the blade may not be easily adjusted relative to the handle and/or may not be easily replaced. In addition, some of such close quarter hack saws are expensive and complicated to manufacture and/or are difficult to use.
Objects
The present invention overcomes these difficulties and has for one of its objects the provision of an improved close quarter hack saw which may be easily used for close quarter work.
Another object of the present invention is the provision of an improved close quarter hack saw in which the blade may be easily removed.
Another object of the present invention is the provision of an improved close quarter hack saw in which the blade may be easily adjusted relative to the handle.
Another object of the present invention is an improved hack saw which is simple to use.
Another object of the present invention is an improved hack saw which is simple and inexpensive to manufacture and assemble.
Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to described, or will be indicated in the appended claims and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
A preferred embodiment of the invention has been chosen for purposes of illustration and description and is shown in the accompanying drawings forming a part of the specification, wherein:
Referring to the drawings, the close quarter hacksaw 1 of the present invention comprises an outer hollow handle 2, an inner frame assembly 3 and a blade guide 4.
The hollow handle 2 comprises upper, lower and rear walls 5,6 and 7, respectively, opposed side walls 9 and a front open mouth 8 adapted to receive the inner frame assembly 3.
The inner frame assembly 3 comprises a rear blade-receiving portion 10 and a front lock portion 11 which are preferably integral (one piece) with each other. The blade-receiving portion 10 comprises upper, lower and rear walls 12, 13 and 14, respectively, and an open front mouth 10B. The blade receiving portion 10 is insertable in the open front mouth 8 of the handle 2 and is held in place therein by any well known fastening means (not shown) extending through openings 3A and 10A in the handle 2 and in the blade-receiving portion 10, respectively. A plurality of staggered (offset) partitions 15-16 extend between the upper and lower walls 12 and 13, respectively, of the blade receiving portion 10 on each side of its longitudinal center line to provide a longitudinal central passageway 19 to guide a blade B within the blade receiving portion 10.
Each partition 15 and 16 in the blade receiving portion 11 has a longitudinal side groove 17 and 18, respectively, which are opposite to and on the same plane with each other. The front lock portion 11 of the blade receiving portion 10 is in the form of a stop plug 20 having a channel 21 therein. The channel 21 is coextensive with the passageway 14 and with the open mouth 10B.
The blade guide 4 comprises a u-shaped body 25 having opposed legs 26 connected together by a base 27 with an open edge 28 opposite the base 27. The blade guide 4 has a pair of outwardly extending guide keys 22 at the rear. The blade guide 4 is slidably mounted within the passageway 19 and the channel 21 through the open front mouth 10B with the guide keys 22 inserted within the opposed side grooves 17-18 in the blade receiving portion. Hence, blade guide 4 is movable within the passageway 19 and the channel 21 with its guide keys 22 sliding in the opposed side grooves 17-18. Movement of the blade handle 4 is limited by the stop plug 20 at the front of the blade receiving portion 10. The guide keys 22 are wider than the channel 21 in stop plug 20 so that they will strike the stop plug 20 and are prevented from further movement. Hence, the blade guide 4 is moveable within the inner frame assembly 3 between the rear wall 7 and the stop plug 20 with the guide keys 22 and the stop plug 20 preventing any further forward movement of the blade guide 4. It will thus be noted that the blade guide 4 cannot be removed from the blade receiving portion 11.
The blade B is the usual form of hack saw blade and is mounted within the blade guide 4 and is moveable relative thereto between the legs 26 thereof. A pair of threadably mounted lock nuts 30 and 31 are provided on opposite sides of the stop plug 20 which are threadably mounted in openings 32 and 33 therein, respectively, located on opposite sides of the stop plug 20. The lock nuts 30 and 31 are planarly offset from each other (on different planes) so that one of the lock nuts 30 is at the same level as the blade guide 4 and the other lock nut 31 is at the same level as the blade B. By tightening the lock nut 30 the blade guide 4 is held in place in a particular position. By tightening the lock nut 31 the blade B is held in a place in a particular position on the blade guide 4.
In operation when it is desired to change the position of the blade guide 4 relative the blade receiving portion 10, the lock nut 30 is loosened. This permits the blade guide to move (with the blade B) within the blade receiving portion 10 in paragraph 19 and channel 21 with guide keys 22 sliding in grooves 17 and 18. When the desired position is achieved, the lock nut 30 is tightened to lock blade guide 4 with blade B in that particular position. When it is desired to remove the blade B or to adjust its position of the blade B relative the blade guide 4, the lock nut 31 is loosened and the blade B is moved relative to the blade guide 4 to the desired position. The lock nut 31 is then tightened to the lock the blade B in that particular position.
It will thus be seen that the present invention provides and improved close quarter hack saw which may be easily used for close quarter work in which the blade may be easily removed, in which the blade may be easily adjusted relative to the handle, which is simple to use and which is inexpensive to manufacture and assemble.
Accordingly, while only a few embodiments of the present invention have been shown and described, it is understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as defined in the appended claims.