Abstract:
A compact clamp design includes an upper and a lower arm fitted with gripping pads at respective front ends and hinged together at respective back ends. The rearward positioned hinge enables the clamp to open very wide since the hinge and the gripping pads are relatively very far apart. An operating handle integrated as part of an upper arm. When the clamp is closed there are no protruding members. The clamp is very compact and minimally obtrusive.

Description:
FIELD OF THE INVENTION 
   The present invention relates to holding clamps. More precisely the present invention relates to a quick action “C” clamp. 
   BACKGROUND OF THE INVENTION 
   Various types of clamps are known. The common “C” clamp is a simple low cost device. A “C” shaped body includes an elongated screw at one end. The screw is advanced toward the opposite end of the clamp to hold an object between. Another well-known type of clamp is a screw actuated pivoted clamp, or cantilevered clamp. A typical version is shown in U.S. Pat. No. 2,726,694. This design allows a large opening size in a relatively compact form, except that the screw and cantilevered arm protrude greatly from the actual clamping structure. A similar clamp is disclosed in U.S. Pat. No. 4,258,908, except that a quick release screw is included to enable faster size closing action. 
   A more self-contained shape is shown in the clamp of U.S. Pat. No. 5,570,500. A sliding cam is hammered to move it along a triple pivot arrangement. Two pivoted arms move to squeeze an object. It is a specialty device that has a limited clamping range. 
   A “Spring Chuck” is shown in U.S. Pat. No. 6,212,977. A plier-like clamp includes pivoting jaw pads and a stepless locking mechanism including a bar and surrounding wedge to bind the bar. The maximum opening size is limited since the pivot or hinge is relatively close to the jaw. A similar design is shown in Exhibit A under the brand name “Quick-Grip Handi-Clamp”. The Handi-Clamp uses an arcuate locking bar rather than the straight bar of &#39;977. A related type of locking plier is shown in U.S. Pat. No. 3,313,190. A conventional steel plier includes a stepless locking bar and related wedge at the handle distal end. The locking bar is curved as in the “Handi-Clamp”. The opening size is very linited since the hinge is very near to the jaws, as is typical is a plier. In the above plier style clamps there is a clear trade-off between available force and clamping force. More leverage or force leads to less possible opening size. 
   Another design uses a two stage closing process to enable fast action and high force. U.S. Pat. No. 2,838,973 is an example of this well known design for locking pliers. A high force clamping action follows a high speed closing motion. However since the hinge is very near to the jaw the possible opening size is small. 
   The prior art all have either limited opening capacity or are not compact in size. Most require two hands to operate. It is desirable to have a clamp that is: compact, one handed, large capacity and have high force. 
   SUMMARY OF THE INVENTION 
   The present invention provides many improvements to the function of a clamp. An upper and a lower arm are fitted with gripping pads at their front ends and hinged together at respective back ends. The designations of upper and lower are arbitrary; naturally the clamp may be operated in various positions with respect to gravity or other reference factor. This design contrasts with the typical prior art quick action clamps that use the plier type design. An advantage of the rearward positioned hinge is that the clamp can open very wide since the hinge and the gripping pads are relatively very far apart. The present invention clamp comprises primarily just two arms with an operating handle integrated as part of an upper arm. When the clamp is closed there are no protruding members. The clamp is thus very compact and minimally obtrusive. Such compactness may be compared to a hand that has just a thumb and one opposed finger. 
   In the preferred embodiment the clamp operates by means of one hand through its full range of motion. Pressing the handle causes the lower arm to move up toward the upper arm. A two-stage action links the handle, through the upper arm, to the lower arm. A first stage includes a fast closing motion and second stage includes a slow clamping motion. The first stage is a high arm speed, low arm leverage action that serves to position the clamp gently about or adjacent to an object. The fast first stage continues until the pad of the lower arm meets an obstruction. The obstruction will be either the object that is being clamped or the opposed upper pad if the clamp is empty. A clutch releases a handle-to-lower arm linkage, corresponding to the first stage, as the handle is urged to press against the obstruction. At a predetermined position of the handle, the second stage clamping action begins. Some handle travel normally occurs between the point that the lower arm meets the obstruction (end of first stage) and the actual clamping action starts (start of second stage). The extent of such transitional travel depends on how far the clamp has closed when it meets the obstruction, less transition for small objects, more for large objects. This is discussed further in the detailed description. The high leverage of the second stage enables tight clamping of the object. 
   In the first stage the handle pivots between outer positions within the upper arm. The clutch preferably pivots about the same position in the upper arm and is further pivotal relative to the handle. The clutch includes an extension that defines a lower distal end of a handle assembly. This lower distal end presses a suitable engagement point of the lower arm such that a small motion of the handle produces a large motion of the lower arm. This first stage engagement point lies between the handle pivot and the rearward hinge of the respective arms. When the lower arm can move no more, the clutch partially releases so that the handle can continue to move even as the lower arm does not, the handle pivoting in relation to the “stationary” clutch and lower arm. The clutch retains some linking force between the handle and lower arm after clutch release so that the lower arm does not reopen while the handle is in the transitional travel mode approaching the second stage. 
   The second stage involves high forces and thus relies upon hardened steel linkages. This contrasts with the elements of the low force first stage that may be of plastic material. The handle contains a steel lever with gear teeth at the lower end of the lever. The lever pivots about the same point of the upper arm as the handle. The lower arm contains a gear that can mesh with the teeth of the lever. At the predetermined position of the handle the lever is urged to engage the gear, while the clutch holds the lower arm in position. The geometry of the lever and gear is such that the lever has a high leverage upon the gear. This means that the handle, that includes the lever within, can exert a strong closing force upon the lower arm that contains the gear within. This high leverage mode comprises the second stage. The handle pivots about the upper arm upon a fixed location while the lever can translate or slide slightly within the handle to engage or disengage the lever from the gear. 
   The dual action of the present invention clamp enables a single stroke of a handle to, first adjust a clamp size, and second to squeeze an object so sized. The operation of the distinct stages is not obvious to a user. The combined closing and clamping action thus feels like a single and unexpectedly efficient process. The long reach of the arms of the clamp allows it to hold large objects using a compact form. The actuating element, in this case the handle, is a minimally protruding member of one of the clamp arms. 
   In a preferred embodiment the lever is held in a clamped position through a stepless locking mechanism. Thus the lever will not retract even slightly after it is pressed into position. This provides the second stage clamping action with a maximum possible holding force. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevation of a clamp of the invention, in partial cut-away sectional view, with the lower arm and handle in a fully open position. 
       FIG. 2  is the clamp of  FIG. 1 , in a position just beginning the second stage clamping action. 
       FIG. 3  is the clamp of  FIG. 2 , in a fully tightened position. 
       FIG. 3A  is a detail view of a lever holding mechanism. 
       FIG. 4  is a cut-away partial sectional view of the clamp of  FIG. 2 , viewed from an opposite side. 
       FIG. 5  is an exterior view of the clamp of  FIG. 3 . 
       FIGS. 6A to 6F  are views of an upper arm. 
       FIG. 6A  is a side elevation of the upper arm. 
       FIG. 6B  is the upper arm of  FIG. 6A , in partial section. 
       FIG. 6C  is the upper arm of  FIG. 6A , view from an opposite side. 
       FIG. 6D  is the upper arm of  FIG. 6C , in partial section. 
       FIG. 6E  is a top view of the upper arm. 
       FIG. 6F  is a front view of the upper arm. 
       FIGS. 7A to 7E  are views of a lower arm. 
       FIG. 7A  is a top view of the lower arm. 
       FIG. 7B  is side elevation of the lower arm of  FIG. 7A . 
       FIG. 7C  is the lower arm of  FIG. 7B , in partial section. 
       FIG. 7D  is a bottom view of the lower arm. 
       FIG. 7E  is the lower arm of  FIG. 7C , view from an opposite side. 
       FIGS. 8A to 8F  are views of a handle. 
       FIG. 8A  is a side elevation of the handle, partially in section. 
       FIG. 8B  is an exterior view of the handle of  FIG. 8A . 
       FIG. 8C  is a side elevation of the handle of  FIG. 8A , partially in section and partially hidden, viewed from an opposite side, with a lever in its respective position. 
       FIG. 8D  is the handle of  FIG. 8B  viewed from an opposite side. 
       FIG. 8E  is a bottom view of the handle. 
       FIG. 8F  is a front view of the handle. 
       FIGS. 9A to 9C  are views of a clutch. 
       FIG. 9A  is a side elevation of the clutch, with a spring installed. 
       FIG. 9B  is the clutch and spring of  FIG. 9A  viewed from an opposite side. 
       FIG. 9C  is a bottom view of the clutch of  FIG. 9B . 
       FIG. 10A  is an end view of a gripping pad. 
       FIG. 10B  is a side elevation of gripping pad. 
       FIGS. 11A to 11D  are views of a front guide. 
       FIG. 11A  is a front elevation of the front guide. 
       FIG. 11B  is a side elevation of the front guide. 
       FIG. 11C  is a sectional view of the front guide of  FIG. 11B . 
       FIG. 11D  is a rear elevation of the front guide. 
       FIG. 12  is a side elevation of a gear. 
       FIG. 13  is a side elevation of a lever. 
       FIGS. 14A to 14C  are views of a release member. 
       FIG. 14A  is a front elevation of the release member. 
       FIG. 14B  is a side elevation of the release member. 
       FIG. 14C  is a bottom view of the release member 
       FIG. 15  is a side elevation, partly in section, of a release position of an alternate embodiment ratcheting clamp. 
       FIG. 16  is the clamp of  FIG. 15 , at the end of a final ratcheting stroke. 
       FIG. 17  is the clamp of  FIG. 16 , with the handle in its upper ratcheting position. 
       FIG. 18  is a side elevation view of an upper arm according to an alternate embodiment of the invention. 
       FIG. 19  is the upper arm of  FIG. 18 , the arm and a frontguide viewed partly in section from an opposite side from  FIG. 18 , including a release member in a locked condition. 
       FIG. 20  is a detail view of the arm of  FIG. 19 , with the release member in an unlocked condition. 
       FIG. 21  is the detail view of  FIG. 20 , with the frontguide viewed in side elevation. 
       FIGS. 22A to 22C  are views of an alternate embodiment release member. 
       FIG. 22A  is a front elevation of the release member. 
       FIG. 22B  is a side elevation of the release member. 
       FIG. 22C  is a bottom view of the release member. 
       FIG. 23  is a view partly in section of an upper arm assembly in the area of the release member. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1 to 3  show the primary components and operating principles of the clamp of the present invention. The clamp is being used to hold two blocks  200  together in the exemplary Figures. In  FIG. 1  the clamp is fully open. Handle  30  is in its uppermost rotational position, while lower arm  20  is rotated to its lowermost position. Handle  30  rotates about dowel  111  that is fitted into hole  11 A of upper arm  10 . See dowel  111  also in  FIG. 5 . Clutch  50  is engaged in  FIG. 1 , wherein cam  54  of clutch  50  rests upon ledge  32  of handle  30 . Hole  56  of clutch  50  fits about post  36 ,  FIG. 8D , of handle  30 . See also  FIGS. 8 and 9 . Clutch  50  can therefore rotate about post  36 . Spring  90  provides a bias within clutch  50  tending to spread the clutch to hold cam  54  in engagement. If clutch  50  is made of a suitably resilient material then flexible segment  53  could provide the bias without the assistance of spring  90 . Clutch distal end  51 , visible in cut-away in  FIG. 1 , hidden view in  FIGS. 2 and 3 , presses cam  21  of lower arm  20 . In the fully open position of  FIG. 1  stop  15  of upper arm  10  limits the motion of lower arm  20  at stop  23 . Stop  23  is visible in  FIGS. 1 and 4 , but is cut away in  FIGS. 2 and 3 . Stop  23  defines the most open possible position of the clamp, limiting factors including the size of the section of gear  60  that includes an arcuate array of teeth  65 , and maintenance of a reasonable distance between grip pads  70  and hinge dowel  110 , or “throat” distance. 
     FIG. 1  represents the start of the first stage of clamping. In this stage lower arm  20  will be moved up to contact blocks  200 ,  FIG. 2 . Pressing handle  30  downward causes the handle, and clutch  50 , to rotate about dowel  111 . Clutch distal end  51  presses upward on cam  21  of the lower arm, causing the lower arm to rotate toward the upper arm about hinge dowel  110 . Dowel  110  fits through hole  11 B,  FIG. 6 , of upper arm  10 , and hole  26  of lower arm  20 ,  FIG. 7 . When grip pads  70  are positioned about blocks  200 ,  FIG. 2 , lower arm  20  can move no more. If handle  30  is forcibly moved further, clutch  50  will remain largely stationary within upper arm  10 , since the obstruction created by blocks  200  prevents the lower arm and thus cam  21  from moving any further. Clutch  50  will then release whereby cam  54  slides out of contact with ledge  32 . In  FIG. 2  this sliding disengagement is just beginning. If blocks  200  were thicker lower arm  20 , and cam  21 , would be immobilized earlier in the stroke of handle  30 . Clutch  50  would then release with handle  30  in a higher position than that shown in  FIG. 2 . In any case the release of clutch  50  represents the end of the first stage closing action. In  FIG. 2 , the position of handle  30  is slightly above the predetermined position of the start of the second stage clamping action. In the case of the larger blocks  200 , handle  30  would need to rotate further to reach the start of the second stage since the first stage would end with a higher handle position. Rotation of handle  30  between the end of the first stage and the start of the second stage is called transitional travel. The start of the second stage is a fixed handle position while the end of the first stage depends on the size of the clamped object, and the related position of the handle. The amount of transitional travel will therefore depend on the object size. As an example, if the object were sized to span the maximum distance represented by the opening in  FIG. 1 , clutch  50  releases nearly instantly with no motion of lower arm  20 . Handle  30  will then move from the uppermost position of  FIG. 1  to a lower position just past that of  FIG. 2 . During this transition, no apparent action occurs on the arms of the clamp. 
   However during the transition, transition edge  55  of the clutch,  FIG. 3 , presses wall  37  of handle  30  at all times that the clutch is disengaged. The geometry of this interaction is such that clutch  50  is always biased to return to the engaged state of  FIG. 1  by sliding of edge  55  down along wall  37 . This transition bias serves two functions: to reset the clutch for another cycle, and to maintain lower arm  20  in position against the under side of blocks  200  during the transition travel of the handle through continued pressure between distal end  51  and cam  21 . Optionally one or both surfaces of edge  55  and wall  37  may directionally serrated to increase the sliding resistance between the surfaces. This increase would add more force to hold lower arm  20  in its up position against blocks  200 . 
   At a handle position just below that shown in  FIG. 2 , the second stage clamping action begins. The second stage comprises an interaction between lever  40 ,  FIG. 13 , and gear  60 ,  FIG. 12 . At the lower end of lever  40  is a set of teeth  43 . Gear  60  has corresponding teeth  65 . In  FIGS. 1 to 3  clutch  50  is cut away to show these teeth. Lever  40  is fitted within handle  30 . Lever  40  can slide slightly within handle  30  by motion of the lever about dowel  111  in slot  45 . Slot  45  is best seen in  FIG. 8C , and as a hidden line in  FIGS. 1 to 3 . Hole  31  of handle  30  contains dowel  111 . Cross rib  35  holds lever  40  from moving down in handle  30 ,  FIG. 8C . The handle is therefore rotatably fixed within upper arm  10 . However slot  45  enables the lever to translate front to back within the handle. In  FIGS. 1 and 2 , the start and end of stage  1  closing, the respective teeth  43  and  65  are separated and do not interact. In  FIG. 1  slot  45  can be seen extending up from dowel  111 . This means that lever  40  is moved up and away from gear  60 . In  FIG. 2  dowel  111  is in an intermediate position within slot  45 . Lever  40  is moving toward gear  60 . The lever translation is controlled by sliding contact between cam  42  of the lever and ramp  12  of the upper arm. In  FIG. 1  cam  42  and ramp  12  are holding the lever up. In  FIG. 2  cam  42  has moved to a lower position against ramp  12 . Lever teeth  43  are prepared to engage gear teeth  65  in  FIG. 2 . A gap is visible under cam  42  indicating that lever  40  is loosely confined in its sliding motion in  FIG. 2 . Cross rib  35 ,  FIG. 8 , holds lever  40  from falling out of handle  30 , but is located to enable assembly of the lever into the handle. 
   To ensure that the lever is urged to engage gear  60 , frontguide  100  presses stem  41  of lever  40  for all handle positions below that of  FIG. 2 , this being during the stage  2  clamping motion. Frontguide  100  is resilient so that as stem  41  slides past, see also  FIG. 11 , face  105  pushes the lever rearward as the frontguide flexes forward to accommodate stem  41 . Frontguide  100  is fixed at its lower end at tabs  101  and catch  102 . Tabs  101  fit into notches  17  of upper arm  10 ,  FIG. 6 . Catch  102  snaps over rib  13  of the upper arm during a one-time assembly operation. The vertical part of frontguide  100  is free to flex forward about the anchor defined by tab  101  and catch  102 . 
   Optional smooth edge  44  of lever  40  is a synchronizing feature that helps ensure that lever teeth  43  and gear teeth  65  do not engage on their respective points as the lever moves downward and frontguide  100  pushes the lever into gear  60 . A further synchronizing feature is shown at stops  22  of lower arm  20 ,  FIGS. 1 and 2 , as a gap between extension  62  of gear  60  and stops  22 . Gear  60  preferably includes the lever like extension  62  to transmit torque created by lever  40  during second stage clamping to the body of lower arm  20 . As the lever teeth engage the gear at the start of second stage clamping, gear  60  rotates slightly about hole  26  and dowel  110  within lower arm  20 . In  FIG. 3  gear  60  has rotated and the gap at  22  is gone. The process of closing this gap produces a gentle rolling motion between lever teeth  43  and gear teeth  65 . This provides an opportunity for the teeth to mesh before high force is applied to the teeth. Optionally smooth edge  44  could be eliminated so that teeth  43  would clear gear teeth  65  just by rotating the handle upward. Slot  45  could also be a simple hole, with no translation of the lever needed to clear gear teeth  65 . 
   In  FIG. 3  the clamp is fully closed and pressed about blocks  200 . Lever teeth  43  are fully engaged into gear teeth  65 . The handle/lever assembly has been moved as far as it can go down toward upper arm  10 . It can be seen that further travel of the lever into the upper arm is possible if gear  60  and associated lower arm  20  were free to rotate further upward. However the obstruction of blocks  200  prevents further travel. The particular stopping point of the lever depends on two items: how closely the arms were positioned about blocks  200  during the first stage closing, and upon the precise position of gear teeth  65  as determined by the thickness of blocks  200 . The first item, positioning, is affected by the strength of clutch  50  engagement and transition bias discussed above (wall  37  and edge  55 ), as well as how the operator holds blocks  200  or other objects. In a worst case if the clamp is positioned too loosely in closing, then more of second stage clamping motion is needed to move the lower arm into position. Since second stage clamping produces high force but relatively little arm motion, it is possible that lever  40  will move down to its limit within upper arm  10  while blocks  200  are still not adequately pressed together. It is then necessary to open the clamp again to get the arms closer in first stage closing. It has been found in practice that adequate clamping is most often achieved before the lever bottoms out. The second item, which tooth  65  of gear  60  is first caught by lever teeth  43 , especially determines how far down the lever will ultimately move. In  FIG. 2  it can be seen that gear tooth  65 A is going to be caught first by lever teeth  43 , the lever teeth having just missed the adjacent tooth below  65 A. However if blocks  200  were slightly thinner, the next down tooth would in fact be caught first since the gear teeth  65  would all be higher when first stage closing is done as in  FIG. 2 . 
   In  FIG. 2  frontguide  100  presses stem  41  rearward, and thus teeth  43  into gear teeth  65 . However there will be some wasted motion, as the first or top tooth  43  must move up substantially to meet and press gear tooth  65 A. Therefore lever  40  will have moved down relatively far by the time blocks  200  are well pressed together. The final clamping position is in  FIG. 3 . In contrast if the gears had meshed immediately in  FIG. 2  the final position shown in  FIG. 3  would have the lever/handle assembly higher since there would be no take up of gear lash. The Figures show a best case with respect to how well the arms are pre-positioned (first stage) about the blocks. In reality there would be some additional closing motion needed in the second stage to abut the blocks before clamping, so the respective position in  FIG. 3  would have the lever/handle lower. In fact much of the motion available in second stage clamping, represented by the length of stem  41 , is to provide for final arm closing and gear meshing. Only a small motion is needed to actually squeeze blocks  200 . A finer resolution of the gear teeth will minimize the worst-case motion needed for gear meshing. However the tooth size must be adequate for strength. 
   While a user will press handle  30  to squeeze blocks  200 , there must be a way to hold the clamp after the user is done squeezing. This is a key function of stem  41 . Release  80 ,  FIGS. 1–3 ,  3 A, and  14 , wedges about stem  41  for any position of stem  41  within slot  81  of release  80 . Release  80  pivots within slot  14  of arm  10 ,  FIG. 3A . Slot  14  is seen alone in  FIGS. 6A , and  6 D. Upward force upon stem  41  causes release  80  to press upward in slot  14 , at surface  85  of release  80 . Such pressing produces a bending moment on release  80  relative to stem  41 . This causes release  80  to grab stem  41  thereby holding lever  40  in a down position. Stem  41  could optionally use a toothed ratchet action. However a stepless action as shown is desirable to reduce any kickback of lever  40 . Any upward free-play in lever  40  would cause the arms to back off of blocks  200 , wasting available clamping force. Tabs  105   a  and  105   b  of face  105 ,  FIG. 11D , keep stem  41  centered about slot  81  as the stem enters the slot. 
   In the illustrated embodiment release  80  binds about rectangular sectioned, or other elongated sectioned such as ovoid, stem  41  by pressing the wide side surface of stem  41 . The stem thus includes a narrow thickness and a larger width. The wide side surface or width of stem  41  is shown in all drawings of the stem other than  FIGS. 3A and 23 , where the thickness is shown. The release element or “binding wedge” pivots about a location facing the wide surface (slot  14  or  214 ) as best seen in  FIGS. 3A and 23 . This contrasts with the typical prior art stepless binding methods, such as in a quick action bar clamp. In such prior art designs a stem or bar of elongated sectional shape fits through a corresponding shaped slot in a wedge element. The wedge binds the bar at the thin edges of the bar, the wedge pivoting about a point facing the thin surface of the bar. The thin edges may be straight or arcuate in the case of an ovoid sectional bar. Thus the extent of the binding surface is defined by the thickness of the bar in the prior art designs. In the present invention the binding surface is much greater since it is upon the width or wide side surface of the bar, and normally includes the entire width. A larger binding surface prevents damage to the wedge or bar that may occur from high stresses if a high force were applied by binding just the thin edge of the bar. Therefore a compact wedge element can provide a high binding force by binding upon a much larger surface in the present invention. This improved binding method could be applied to any mechanism that uses a stepless binding system, such as bar clamps, caulking guns, jacks, etc. 
   To open the clamp a user presses release  80  at tab  83 , to the right in  FIG. 3A . This causes release  80  to rotate within slot  14 , clockwise in  FIG. 3A , breaking the hold of stem  41 . The lever/handle assembly moves upward from the configuration of  FIG. 3  toward that of  FIG. 1 . As the clamp opens stem  41  moves up past face  105  of frontguide  100 . Lever  40  is then free to move out of engagement with teeth  65  of gear  60 . Cam  42  presses ramp  12 , ensuring that the respective teeth remain out of engagement. The clutch reset discussed above, using edge  55  and wall  37 , causes clutch  50  to revert to the state of  FIG. 1 . Handle  30  at the same time reverts to its linkage to lower arm  20  by way of clutch distal end  51  and cam  21 . A further element of the opening process is return spring  190 ,  FIG. 4 . Torsion spring  190  presses down upon arm  10  at support  191 . Dowel  111  forms a central mandrel for the spring. At the rear spring  190  presses down upon tab  64  of gear  60 . Tab  64  extends out of the page in  FIG. 4 , into the page in the opposite view  FIG. 12 . Spring  190  thus creates a bias to move lower arm  20  away from upper arm  10 , through the linkage of gear  60 . A secondary bias occurs against gear  60  relative to lower arm  20 . By pressing at tab  64  rather than directly on lower arm  20 , spring  190  urges extension  62  of gear  60  away from stops  22  in lower arm  20 . As discussed earlier the resulting gap provides an opportunity for gear  60  to rotate slightly and for the respective gear teeth to mesh before high force is applied to the teeth. Spring  190  holds this gap open until the start of second stage clamping forces gear  60  to pivot slightly within lower arm  20 . 
   Frontguide  100  includes elements that interact with release  80 . Resilient arm  103  provides a bias to hold release  80  at an angle to ensure that release  80  binds upon stem  41 . Release  80  pivots in slot  14  about surface  85 ,  FIG. 3A . To free stem  41  a user presses tab  83  toward surface  19  of upper arm  10 . Tab  83  is spaced from surface  19 ,  FIGS. 3A ,  4  and  6 . The lower portion of release  80  moves downward as tab  83  is pressed. This lower portion includes angled tab  84  that slides along ramp  104  of frontguide  100 . As tab  84  moves down, it forces the frontguide to deflect forward, to the left in  FIGS. 1 to 3 . Surface  105  then moves away from, or at least presses more weakly upon, the front edge of stem  41 . The action of tab  84  causes a net rearward force upon release  80 . To hold release  80  in position rear wall  82 ,  FIG. 14B , slides against rib  16  of upper arm  10 . 
   In  FIGS. 18 to 23  an alternate embodiment release and frontguide design are shown. In this design the frontguide presses the release member directly in the release action. This contrasts with the above embodiment of  FIGS. 11 and 14  where the release member presses the frontguide. An advantage of the present alternate embodiment is that the frontguide is directly urged to clear stem  41  of lever  40  to enable the lever to rotate upward freely. 
   In  FIG. 19  the elements of the alternate embodiment are all shown. Lever  40  is held in slot  281 ,  FIG. 22C , of release member  280 . In the locked condition of stem  41 , release member  280  is angled,  FIG. 23 . Frontguide  230  pivots about point  232  and is biased clockwise in  FIG. 19  by resilient extension  231  pressing rib  311  of upper arm  310 . The clockwise bias of the frontguide causes corner  235  to press stem  41  rearward. Teeth  43  are thus urged to engage further gear teeth, not shown, of gear  60 ,  FIG. 12 , according to the mechanism described for  FIGS. 1 to 3 . Arms  233  of frontguide  230  straddle stem  41 . Points  232  of arms  233  may comprise outward extensions, not shown, that engage corresponding holes in upper arm  310 . Frontguide  230  can be assembled into upper arm  310  by forcibly sliding the fronguide into the opening of upper arm  310 ,  FIG. 23 . The outward extensions of the frontguide will snap into the corresponding holes of the upper arm through spreading action from the resilience of extended arms  233 . 
   Release member  280  pivots about edge  317  within upper arm  310 ,  FIG. 23 . Tab  283  extends into slot  316 , holding release member  280  in position laterally. Release member  280  must be biased upward, or counterclockwise in  FIG. 23 , to hold release  280  at an angle to ensure that release  280  binds upon stem  41 . A member similar to resilient arm  103  described above may provide the bias. Or as illustrated in  FIGS. 19 to 23 , an alternate embodiment may be used. The resilient bias member here is rib  313 ,  FIGS. 18 and 23 . Gap  318  creates rib  313 . More convoluted shapes for rib  313  could provide greater resiliency. Bump  312  of rib  313  presses under release member  280 . As stem  41  binds in slot  281 , release member  280  rotates downward to enable the stem to fit, causing rib  313  to deflect. The horizontal distance between edge  317  and bump  312  of rib  313  defines a torsion arm that gently rotationally biases the release member. Alternately a resilient material such as rubber could be fitted to upper arm  310  in the regions of rib  313  and gap  318  to serve the same biasing function upon release member  280 . In  FIGS. 18 and 23 , stiffening rib  319  adds strength and a place to fit slot  316 . Release member  280  fits within opening  314 ,  FIGS. 18 and 23 ;  FIG. 18  shows only upper arm  310 , without further components. 
   In  FIG. 19  the assembly is in the locked condition with stem  41  bound in slot  281 . In  FIGS. 20 and 21 , the assembly is in the released condition. In  FIG. 21 , corner  236  is pressing release member  280  down so that the release member is not angled in contrast with  FIG. 19 . Corner  236  is cut away in the section view of the frontguide in  FIG. 20 . Frontguide  230  is urged counterclockwise by pressing tab  234  forward. The lower distal end of resilient extension  231  slides along rib  311  as frontguide  230  moves forward. It can be seen that extension  231  has moved downward by comparing  FIG. 19  to  FIG. 20 , at the distal end of extension  231 , while extension  231  has also straightened in  FIG. 20 . It can be further seen that corner  235  is spaced from stem  41  in  FIG. 20 . Thus in  FIGS. 20 and 21 , stem  41  is free to move upward. In  FIG. 23  corner  236  is just pressing release member  280  so that release member  280  begins to rotate and slot  281  begins to unbind stem  41 . 
   Returning to  FIGS. 1 to 17 , to accommodate different opening positions of the clamp, pads  70  may pivot about respective holes  18  and  24  of the upper and lower arms. Pads  70  are fitted with posts  72 ,  FIG. 10A , to engage the holes. 
   Based on tests of a working model the presence of two distinct stages is not obvious to users as the clamp closes. Rather the single stroke closing and clamping action feels just like a single stroke. Therefore the present invention feels uncomplicated in use. 
   It is not required that lever  40  and handle  30  rotate together for all positions. Cross rib  35  of the handle could be deleted to allow them to rotate separately. For example as the clamp opens, lever  40  may rise just high enough to disengage lever teeth  43  from gear teeth  65 . A tab, on the end of stem  41  for example, could limit the upward travel of the lever. This would be near the lever position of  FIG. 2 . Handle  30  would continue to rise up to the position of  FIG. 1  to fully open the clamp. This design may be selected if it is desired to more clearly identify the two stages as the handle closes. In the first stage only the handle moves. In the second stage the handle and lever move together. 
   Alternate constructions may be anticipated where the assembly of handle  30  and lever  40  extends toward lower arm  20  and is pulled upward for an actuation stroke. The handle/lever assembly may be refered to generically as a lever. 
     FIGS. 15 to 17  show an alternate embodiment of the present invention. The arms close by means of a ratcheting action upon the handle. The handle is repeatedly pressed down and allowed to return to an upper ratcheting position. A maximum height of the handle corresponds to a release position of the handle. The components of the single stroke two stage design described above may be adapted to the ratcheting embodiment of the clamp, with some modifications. 
   In  FIG. 15  the release position is shown. Upper arm  210  pivots about pin  410  in relation to lower arm  220 . Pads  70  press blocks  200  during clamping. Handle  530  rotates about pin  411 , where pin  411  is further fitted in respective holes, not shown, in upper arm  210 . Lever  240  is held within handle  530 . Lever  240  rotates along with the handle about pin  411 , and includes an elongated lever slot to fit around pin  411  such that lever  240  may translate slightly longitudinally relative to handle  530 . This allows teeth  243  to align or synchronize with gear teeth  265  as handle  530  is lowered from the position of  FIG. 15  to that of  FIG. 17 , where the ratcheting process starts. Smooth edge  244  of lever  240  holds the lever away from the gear teeth until a suitable position is reached wherein the respective teeth are aligned as the handle moves down. This synchronizing function is similar to that for the single stroke version of the invention described above. To move lever  240  away from gear  260  in the release position, cam  242  of lever  240  slides up ramp  212  to cause the lever to move away from the respective teeth  265  of gear  260 . 
   In the exemplary embodiment a second set of coaxial gear teeth  265   a  are fixed to gear  265 . These gear teeth define a smaller radius than that of teeth  265  in the Figures. They may define an equal or larger radius if preferred. Teeth  265   a  engage teeth  255  of detent  250  to hold the clamp in position after an advancing stroke has been completed. Detent  250  is spring biased, not shown, to engage the respective teeth  265   a  and  255 . Detent  250  pivots about pin  412 , with the pin supported in upper arm  210 . Alternately, instead of coaxial gear teeth  265   a , the arc formed by teeth  265  could extend further downward or rearward along gear  260 , and detent  250  be positioned respectively below or above the engagement zone of teeth  243 . Further the positions of detent  250  and gear teeth  265   a  could be reversed whereby a detent may be rotatably fixed to the lower arm and an arcuate set of teeth for the detent to engage fitted to the upper arm. 
   The lower end of detent  250  is a detent trigger that serves to disengage the detent from gear  260 . In  FIG. 15  detent trigger  250  has been depressed rearward so that a space is visible at detent teeth  255 . This has allowed lower arm  220  to open to the position shown. Preferably the handle rises to the uppermost position in  FIG. 15  only when the trigger of detent  250  is pressed. This occurs through a tab or other linkage, not shown, between detent  250  and lever  240  or handle  530 . If the trigger is not pressed then the handle does not rise past the position of  FIG. 17  when the handle is released. 
   A closing stroke is represented in  FIGS. 16 and 17 . The handle is repeatedly pressed and released to close lower arm  220  in increments toward the obstruction of blocks  200  in a ratcheting process.  FIG. 16  shows a lowermost handle position for the particular thickness of blocks  200 , as may occur when the obstruction is reached and the arms can close no further. The resulting “last stroke” of the handle closely resembles the second stage stroke of the two stage closing embodiment above, with the difference that multiple strokes are used in the present ratcheting embodiment to close the arms rather than the fast action first stage of the two stage embodiment. The handle is able to go lower than in  FIG. 16  if the obstruction of blocks  200  is not yet reached. When the handle is released between strokes it raises up to the position of  FIG. 17 , being stopped preferably by the aforementioned link to detent  250 . Lever  240  has a light bias spring, not shown, to urge the lever toward gear  260 . In the return stroke the respective backside angles of the lever teeth  243  and gear teeth  265  allow the lever to ride up the gear against the bias of the light spring, producing a characteristic ratcheting sound. When the handle is in the full up release position, and smooth edge  244  holds the lever away from the gear, there will be no tooth engagement. 
   Detent  250  will hold gear  260 , or any other element that the detent engages, in a finite set of positions determined by the resolution of the respective teeth. In certain conditions the arms will separate slightly after the last stroke of the handle as detent  250  finds an engagable set of teeth  265   a  with which to seat. To retain a squeezing force upon blocks  200  as gear  260  rotates back slightly, counterclockwise in  FIGS. 15 to 17 , spring  295  may press extension  262  of gear  260 . Spring  295  should maintain a bias through a rotation of gear  260  equivalent to one tooth of the gear. Then as the gear rotates back, a net squeezing force remains. In  FIG. 16  the last stroke has been completed, and gear  260  is rotated to its maximum clockwise position in lower arm  220 , so that the extension is contacting the stop ribs to each side of spring  295 . Note slight spaces between detent teeth  255  and teeth  265   a  in  FIG. 16 . The detent has not seated in this position. In  FIG. 17  the last return stroke is completed and gear  260  with teeth  265   a  rotate counterclockwise until teeth  255  are fully seated. It can be seen that extension  262  has moved downward in the lower arm. However spring  295  continues to force lower arm upward to squeeze blocks  200 . Spring  295  may take a variety of forms and locations. For example it may be a flat spring or a conical spring washer. Spring  295  biases the gear in the same direction as spring  190 ,  FIG. 4 , of the two stage version. However spring  295  of the ratchet design is much more stiff than spring  190  of the two stage design since the respective functions are quite different. Spring  295  contributes directly to the squeezing action, while spring  190  provides a light synchronizing motion. 
   The embodiments of the two stage closing clamp and the ratcheting clamp include many similar elements and concepts in the illustrated embodiments. The leverage of a handle is used in an actuating stroke to squeeze two opposed arms about an object. One difference may be the method used to hold the arms in a squeezing state. The present embodiment two stage design holds the lower arm indirectly by grabbing and holding the lever, while the ratcheting design directly holds the lower arm by a detent. A second difference is the method for positioning the arms about an object. The two stage design uses a disengagable fast motion first stage to close the arms. The ratcheting version uses multiple ratcheting strokes to incrementally close the arms. In either version it is normally possible to use a second hand to position the arms about the object instead of first stage closing or multiple ratcheting strokes. However one feature of the present invention is that it may be used with only a single hand. 
   In the illustrated embodiments particular shapes for the various components are shown. Other shapes may be used depending on design choice. Also other locations or designs for certain components may be used. For example release  80  and stem  41  may be located elsewhere on upper arm  10 , such as closer to dowel  111  or even behind dowel  111 . In the ratcheting design detent  250  may be oriented or positioned elsewhere, such as with the trigger extending upward from pin  412 . A detent similar to  250  may be substituted into the two stage design in place of release  80  and stem  41 . In this option the lower arm is held more directly rather than through an element of lever  40 . 
   In a further variation the clamp closing may be caused or assisted by action upon gear  60 . A lever, cam or other interface could operate on extension  62  to force gear  60  to rotate, counterclockwise in the Figures, in relation to lower arm  20 . If gear  60  is fixed relative to upper arm  10 , the lower arm moves toward the upper arm. This leveraging could be instead of the second stage clamping. Or it could provide a supplement to second stage clamping to squeeze an object more tightly. Similar leveraging of gear  260  could supplement a final ratchet stroke of the ratcheting design of  FIGS. 15 to 17 , or directly provide the ratcheting stroke by pressing gear  260  against a detent within upper arm  210  as lower arm  220  moves toward upper arm  210 .